US20050130647A1 - Wireless lan system, communication terminal and communication program - Google Patents

Abstract

A wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point.

Description

BACKGROUND OF THE INVENTION
• The present invention relates to a wireless LAN system in which data communication between a wireless access point and a wireless station is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point, a communication terminal usable in the wireless LAN system, and a communication program.
• Nowadays, the so-called wireless LANS, realizing data communication among a plurality of wireless stations or data communication between a wireless station and an external network by use of radio waves, have become widespread.
• In the wireless LANs, various communication methods, such as “infrastructure mode” in which each wireless station carries out radio communication via a repeater station and “ad hoc mode” in which wireless stations directly communicate with each other by radio, are employed. Each wireless station, configured to be capable of switching its communication method depending on the purpose, is generally used in the “infrastructure mode”.
• In a network employing the “infrastructure mode”, the wireless station becomes capable of accessing a wireless access point by adjusting various settings (connection method, etc.) of its own. The “connection method” system a method of wireless connection which is specified by, for example, a wireless LAN standard (IEEE802.11b, -a, -g. etc.) employed for the wireless connection, a frequency range (the so-called “channel”) employed in the wireless LAN standard, etc.
• The above various settings of each wireless station would be completed easily if the wireless station had a user interface of high operability like that of a personal computer (hereinafter abbreviated as “Pc”).
• However, with wireless stations equipped with a user interface of lower operability compared to that of a PC (e.g. printers providing services via a network), adjusting the settings through the user interface becomes an extremely complex and troublesome task.
• To avoid the problem, there exist some wireless stations configured to support “remote setup”. For example, the communication method of the wireless station (first wireless station) is changed to the “ad hoc mode” together with another wireless station (second wireless station) and the settings of the first wireless station are made indirectly from the second wireless station (remote setup) by exchanging data regarding the settings between the wireless stations. Or the wireless station is directly connected to a PC and the settings of the wireless station are made indirectly from the PC by the exchange of data regarding the settings between the wireless station and the PC.
• However, even the remote setup described above is still a troublesome task to the user since the user is required to move the wireless stations (after switching the communication method to the “ad hoc mode”) to positions allowing wireless communication or to move the PC to a position allowing the direct connection to the wireless station by a cable.
• Especially when a wireless station which has been used in the “infrastructure mode” is employed for the remote setup, the user has to return the communication method of the wireless station from the “ad hoc mode” to the “infrastructure mode” after the remote setup is finished, which makes the task more troublesome.
• As described above, in cases of wireless stations equipped with a user interface of lower operability compared to that of a PC (e.g. printers providing services via a network), the adjustment of the settings through the user interface takes time and trouble.
• Recently, some techniques for reducing the time and trouble required for the task of setting have been proposed. In a technique, a network device such as a printer functioning as a wireless station is provided with a function as a wireless access point (relay station), and an independent wireless network is established by the function (relay function unit). From another wireless station connected to the wireless station via the wireless network, settings of the wireless station necessary for establishing connection with another wireless network by its wireless station function (terminal function unit) are adjusted indirectly, and then the function of the wireless station as a wireless access point is stopped. An example of such a technique is disclosed in Japanese Patent Provisional Publication No. 2003-143156.
• By such a technique, the time and trouble necessary for the adjustment of various settings can be reduced for wireless stations that are not equipped with a user interface of high operability.
• However, even though the technique mentioned above can reduce the time and trouble necessary for the task (moving the wireless stations after switching the communication method to the “ad hoc mode” to positions allowing wireless communication or moving the PC to a position allowing direct connection to the wireless station by a cable) accompanying the setting, setting operation itself (operations for adjusting the settings) has to be done by the user.
• Building up a network by wireless LAN requires not only general settings regarding LAN (wired LAN) but also settings (“connection method”) specific to wireless LAN. Since the wireless LAN settings require a wide range of expertise, even users with technical knowledge of wired LAN can not necessarily adjust the wireless LAN settings with ease. Thus, the adjustment of wireless LAN settings is extremely difficult for users unfamiliar with LAN itself.
• As described above, the task of wireless LAN settings is presently a heavy load on the user and it is regarded as a factor blocking the prevalence of wireless LAN. Therefore, techniques capable of reducing the load of the task of wireless LAN settings on the user have been hoped for.
SUMMARY OF THE INVENTION
• The present invention is advantageous in that the load of the task of wireless LAN settings on users as described above can be reduced.
• According to an aspect of the invention, there is provided a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point.
• Specifically, the wireless station includes method switching system, announcement transmission system and method setting system. The method switching system switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals. The announcement transmission system transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method, on each switching of the connection method by the method switching system. The method setting system stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point. Meanwhile, the wireless access point includes notification transmission system which transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station.
• In the wireless LAN system composed as above, the wireless station transmits the announcement data according to each of a plurality of connection methods while successively switching the connection method in turn. The announcement data is received by the wireless access point to which the same connection method (i.e. the connection method of the wireless station at the point of the transmission of the announcement data) has been set, and the wireless access point notifies the wireless station that wireless connection by use of the same connection method as the received announcement data is possible, by transmitting the notification data. The wireless station which received the notification data sets the connection method notified by the notification data (i.e. the connection method set to the wireless access point) to itself. By setting the wireless station to the same connection method as the wireless access point as above, wireless connection between the wireless access point and the wireless station becomes possible.
• As above, in the wireless station, the connection method for the connection to the wireless access point is set automatically by the method setting system via the switching of the connection method by the method switching system and the transmission of the announcement data by the announcement transmission system. Therefore, the load on the user regarding the wireless LAN settings can be lightened remarkably.
• Only by letting the method setting system stop the successive switching of the connection method when the notification data is received, the wireless station can set the connection method at the point of the stop of the connection method switching (that is, the connection method set to the wireless access point) to itself.
• Incidentally, the “connection method” system a method of wireless connection which is specified by, for example, a wireless LAN standard (IEEE802.11b, -a, -g, etc.) employed for the wireless connection, a frequency range (the so-called “channel”) employed in the wireless LAN standard, etc.
• In the wireless station, the “announcement data” transmitted by the announcement transmission system is data for announcing the connection method switched and set by the method switching system to devices around the wireless station. In general, the announcement data is only required to contain parameters indicating the connection method. However, in the case where the wireless access point is configured to receive data according to the preset connection method only, the wireless access point can recognize at the point of the reception of the announcement data that the connection method announced by the announcement data is the same as the connection method preset to itself. Therefore, in this case, the announcement data does not have to contain the parameters indicating the connection method.
• While the timing for the method switching system of the wireless station to start the switching of the connection method is not particularly limited, the method switching system may be configured to start the switching when an instruction from outside is received and/or when the wireless station is started up.
• By such composition, the setting of the connection method to the wireless station can be ordered explicitly from outside. Alternatively or optionally, the setting of the connection method to the wireless station can by initiated simply by starting up the wireless station.
• Incidentally, the “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless station, data transmitted from a communication terminal which is connected to the wireless station to communicate data, etc.
• In the wireless access point, the notification transmission system is a system for transmitting the notification data to the wireless station when the announcement data is received from the wireless station. The notification data is transmitted according to the preset connection method
• The notification transmission system may be configured to transmit a request reminder data, for reminding the wireless station to request permission of the wireless access point for wireless connection, to the wireless station as the notification data when the announcement data transmitted according to the preset connection method is received and thereafter transmit an association reply, giving the wireless station permission for the wireless connection, to the wireless station when an association request as data for requesting the permission for the wireless connection is received from the wireless station.
• By such composition, the wireless connection between the wireless access point and the wireless station can be realized via the exchange of the association request and the association reply, after the setting of the connection method is made by the wireless station.
• While the notification transmission system can transmit the notification data when the announcement data is received regardless of the content of the announcement data, the notification transmission system may also be configured to transmit the notification data to wireless stations transmitting the announcement data satisfying a prescribed condition according to the preset connection method.
• By such composition, the wireless access point is allowed to set the connection method only to wireless stations transmitting the announcement data satisfying the prescribed condition, by transmitting the notification data.
• While the content of the “prescribed condition” in this configuration is not particularly limited, since the wireless station switches the connection method repeatedly until it receives the notification data, “announcement data transmitted twice or more” (via the repetition of the connection method switching) maybe employed as the condition, for example.
• For this, the wireless access point may include announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, and after the collection of the announcement data by the announcement collection system is finished, the notification transmission system may transmit the notification data to a wireless station transmitting announcement data according to the same connection method as announcement data included in the collected announcement data.
• By such composition, the wireless access point is allowed to set the connection method only to wireless stations successively transmitting the announcement data twice or more, by transmitting the notification data.
• Incidentally, the announcement collection system is a system for collecting the announcement data as mentioned above, which collects the announcement data received from wireless stations for a prescribed period of time preparatory for the notification transmission system.
• As the aforementioned “prescribed condition”, “(announcement data of) the highest reception level” may also be employed.
• For this, the wireless access point may include announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, and the notification transmission system may transmit the notification data to a wireless station transmitting announcement data according to the same connection method as announcement data having the highest reception level among the announcement data collected by the announcement collection system.
• By such composition, the wireless access point is allowed to set the connection method to the wireless station transmitting the announcement data of the highest reception level, by transmitting the notification data to the wireless station.
• Such transmission of the notification data to the wireless station transmitting the announcement data of the highest reception level is advantageous for preventing erroneous setting of the connection method of the wireless station to a false connection method different from the method for the connection to the correct wireless access point.
• When the connection method (for the connection to the wireless access point) is set to the wireless station, if another wireless access point having the notification transmission system also exists in the vicinity of the wireless station (e.g. in an adjacent residence), notification data is sent also from the (other) wireless access point to the wireless station and thus there is a possibility that a connection method identical with the method set to the (other) wireless access point might be set to the wireless station regardless of the user's intention, depending on the timing of the reception of notification data.
• However, since the connection method specified by the notification data of the highest reception level can be set as the connection method for the connection to the wireless access point as mentioned above, the erroneous connection method setting based on the notification data from other wireless access points can be avoided only by putting the wireless station and the wireless access point sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
• Incidentally, the announcement collection system in this composition collects the announcement data received from wireless stations for a prescribed period of time, as mentioned above.
• The notification transmission system of the wireless access point may also be configured to transmit the notification data to a wireless station transmitting announcement data that is selected from the announcement data, transmitted according to the preset connection method, based on an instruction from outside.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station that can transmit the announcement data selected based on the instruction from outside, by transmitting the notification data to the wireless station.
• The wireless access point may include announcement collection system which collects the announcement data transmitted according to the: preset connection method for a prescribed period of time, and after the collection of the announcement data by the announcement collection system is finished, the notification transmission system may transmit the notification data to a wireless station transmitting announcement data according to the same connection method as announcement data that is selected from the collected announcement data based on an instruction from outside.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station that can transmit the announcement data selected from the announcement data collected by the announcement collection system based on the instruction from outside, by transmitting the notification data to the wireless station.
• Incidentally, the announcement collection system in this composition collects the announcement data received from wireless stations for a prescribed period of time, as mentioned above.
• The announcement data collected by the announcement collection system may be stored in memory, etc. so that the connection method, for example, can be identified. In this case, the notification transmission system may be configured to transmit the notification data to a wireless station transmitting announcement data that is selected from the collected announcement data based on the instruction from outside.
• The “instruction from outside” in this configuration system, for example, a particular operation by the user to an operation unit of the wireless access point. For this, a configuration described below is possible.
• That is, the wireless access point includes first user selection system which lets a user select one or more wireless stations from the wireless stations transmitting the announcement data collected by the announcement collection system, after the collection of the announcement data by the announcement collection system is finished, and the notification transmission system transmits the notification data to the one or more wireless stations selected by the user through the first user selection system.
• By such composition, the wireless access point is allowed to set the connection method only to the one or more wireless stations arbitrarily selected by the user, by transmitting the notification data.
• For using a particular operation by the user as the “instruction from outside”, a configuration as follows is possible.
• That is, the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data. The announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data. The wireless access point includes second user selection system which lets a user select one or more pieces of the identification data from the identification data associated with the announcement data collected by the announcement collection system, after the collection of the announcement data by the announcement collection system is finished. The notification transmission system transmits the notification data to one or more wireless stations identified by the identification data selected by the user through the second user selection system.
• By such composition, the wireless access point is allowed to set the connection method only to the one or more wireless stations identified by the identification data arbitrarily selected by the user, by transmitting the notification data.
• The “instruction from outside” may also mean data transmitted from a communication terminal which is connected to the wireless access point to communicate data. For this, a configuration described below is possible.
• That is, the notification transmission system of the wireless access point is configured to determine the wireless station to which the notification data should be transmitted according to an instruction from a communication terminal which is connected to the wireless access point to communicate data.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station transmitting the announcement data that is selected (from the announcement data collected by the announcement collection system) based on the instruction from the communication terminal, by transmitting the notification data to the wireless station.
• In this composition, the communication of the instruction with the communication terminal can be realized by, for example, a configuration as follows.
• That is, in a wireless LAN system, the wireless access point includes announcement collection system and listing transmission system. The announcement collection system collects the announcement data transmitted according to the preset connection method for a prescribed period of time and thereby stores data indicating correspondence between the collected announcement data and wireless stations which transmitted the collected announcement data in a storage unit. The listing transmission system transmits listing data, representing a list of wireless stations whose correspondence has been stored in the storage unit by the announcement collection system, to the communication terminal when request data requesting the list of the wireless stations is received from the communication terminal. After the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more wireless stations selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data corresponding to one of the wireless stations represented by the selection data, is received from the wireless station. Meanwhile, the communication terminal includes request transmission system, third user selection system and selection transmission system. The request transmission system transmits the request data to the wireless access point. The third user selection system lets a user select one or more wireless stations from the list represented by the listing data when the listing data is received from the wireless access point after the request data is transmitted to the wireless access point by the request transmission system. The selection transmission system transmits the selection data, representing the one or more wireless stations selected by the user through the third user selection system, to the wireless access point.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless stations arbitrarily selected by the user of the communication terminal based on the correspondences collected by the announcement collection system, by transmitting the notification data.
• Incidentally, the announcement collection system in this composition collects the announcement data received from wireless stations for a prescribed period of time, as mentioned above.
• The announcement data collected by the announcement collection system may be stored in memory, etc. so that the correspondence between the connection method and the source of the announcement data, for example, can be identified. In this case, the listing transmission system may be configured to transmit the listing data, representing a list of wireless stations which can be identified by the stored correspondences, to the communication terminal.
• Optionally, the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data. The wireless access point includes announcement collection system and listing transmission system. The announcement collection system collects the announcement data transmitted according to the preset connection method together with the identification data associated with the announcement data for a prescribed period of time and thereby stores data indicating correspondence between the identification data and wireless stations which transmitted the collected announcement data in a storage unit. The listing transmission system transmits listing data, representing a list of identification data whose correspondence has been stored in the storage unit by the announcement collection system, to the communication terminal when request data requesting the list of the identification data is received from the communication terminal. After the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more pieces of the identification data selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data corresponding to a piece of the identification data represented by the selection data, is received from the wireless station. Meanwhile, the communication terminal includes request transmission system, fourth user selection system and selection transmission system. The request transmission system transmits the request data to the wireless access point. The fourth user selection system lets a user select one or more pieces of the identification data from the list represented by the listing data when the listing data is received from the wireless access point after the request data is transmitted to the wireless access point by the request transmission system. The selection transmission system transmits the selection data, representing the one or more pieces of identification data selected by the user through the fourth user selection system, to the wireless access point.
• By such composition, the wireless access point is allowed to set the connection method only to wireless stations that can transmit the announcement data according to the same connection method as announcement data corresponding to the identification data arbitrarily selected by the user of the communication terminal based on the correspondences collected by the announcement collection system, by transmitting the notification data.
• Incidentally, the announcement collection system in this composition collects the announcement data received from wireless stations for a prescribed period of time, as mentioned above.
• The announcement data collected by the announcement collection system may be stored in memory, etc. so that the correspondence between the identification data and the connection method corresponding to the announcement data (or the announcement data itself), for example, can be identified. In this case, the listing transmission system may be configured to transmit the listing data, representing a list of identification data which can be identified by the stored correspondences, to the communication terminal.
• Each user selection system mentioned above is a system for letting the user make a selection. For example, the user is informed through a display unit, printing unit, speaker, etc. that a selection should be made from options (wireless stations, identification data) by use of an operation unit, and the user makes a selection from the options with the operation unit based on the information.
• Among the wireless access point described above, those including the announcement collection system may be configured as follows.
• That is, the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data. The announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data. The notification transmission system transmits the notification data only to wireless stations transmitting announcement data associated with the same identification data as announcement data already collected by the announcement collection system.
• By such composition, even if the wireless access point receives announcement data by the same connection method as announcement data which has already been collected by the announcement collection system, if the identification data accompanying the announcement data is not identical with identification data accompanying the already-collected announcement data, the transmission of the notification data and the setting of the connection method are canceled. By this, a wireless station trying to illicitly establish wireless connection with the wireless access point by forging announcement data collected by the wireless access point and transmitting the announcement data can be prevented from the wireless connection.
• The announcement collection system may be configured such that, after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data included in the collected announcement data, is received from the wireless station.
• By such composition, the wireless access point can transmit the notification data when the announcement data is transmitted by the wireless station, that is, while the wireless station is capable of transmitting/receiving data, by which the notification data transmitted by the wireless access point is received by the wireless station securely.
• In the wireless LAN systems described above, even if the wireless station is connected to the wireless access point by wireless connection, if the wireless access point is configured to carry out data communication employing encryption, normal data communication is generally impossible without similarly configuring the wireless station to execute the data communication employing the encryption.
• Therefore, for letting the wireless LAN system carry out data communication normally without the need of operations by the user, the wireless access point may include encryption switching system which switches an encryption method employed for the data communication with each wireless station. In cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the notification data by the notification transmission system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the notification data has been transmitted.
• By such composition, even if the wireless access point is configured to execute data communication employing encryption, normal data communication becomes possible without configuring the wireless station to execute the data communication employing the encryption. Therefore, the data communication between the wireless access point and the wireless station can be realized maintaining the security level of data communication of the wireless access point with other wireless stations or external networks.
• As another configuration for letting the wireless LAN system carry out data communication normally without the need of operations by the user, a configuration described below is also possible.
• That is, the notification transmission system of the wireless access point is configured to transmit the notification data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the notification data. The wireless access point includes encryption switching system which, after the transmission of the notification data by the method notification system, switches an encryption method employed for data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key. The wireless station includes encryption setting system which, after the reception of the notification data from the wireless access point sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the notification data.
• By such composition, the wireless access point switches its encryption method to execute data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key. Meanwhile, the wireless station which received the notification data sets itself to execute the data communication with the wireless access point by encrypting data with the second encryption key. By the settings, normal data communication becomes possible between the wireless access point and the wireless station by encrypting data with the second encryption key. Therefore, the data communication between the wireless access point and the wireless station can be realized securing a certain security level while maintaining the security level of data communication of the wireless access point with other wireless stations or external networks.
• In order to increase the security level of the data communication between the wireless access point and the wireless station, a configuration described below can be employed, for example. That is, the wireless station includes: encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system. The communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem. The encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.
• By such composition, the data communication between the wireless access point and the wireless station can be executed encrypting data with the first encryption key transferred from the communication terminal to the wireless station. Therefore, the data communication between the wireless access point and the wireless station can be realized with a security level equivalent to that of data communication of the wireless access point with other wireless stations or external networks.
• Since the transfer of the first encryption key is conducted by system of the public key cryptosystem, the probability of leak of the first encryption key during the transmission to the wireless station becomes low as a matter of course.
• In this configuration, when the communication terminal transfers the first encryption key to the wireless station, it is desirable that the communication terminal can confirm that the wireless station is a correct wireless station to which the first encryption key should be transferred. For this, a configuration described below is possible, for example.
• Optionally, the encryption key transfer system of the communication terminal is configured to transfer an authentication message/signal to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key. The communication terminal includes confirmation operation system which lets a user who confirmed the authentication message/signal outputted by the wireless station carry out a confirmation operation after the authentication message/signal is transferred to the wireless station by the encryption key transfer system. The encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system. The encryption key acquisition system of the wireless station is configured to acquire the authentication message/signal which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key. The wireless station includes message/signal output system which outputs the authentication message/signal acquired by the encryption key acquisition system. The encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication message/signal outputted by the message/signal output system.
• By such composition, the user is allowed to confirm whether or not the wireless station is a correct wireless station that should receive the first encryption key from the communication terminal, by checking whether or not the authentication message is outputted by the wireless station. After confirming the authentication message outputted by the wireless station, the user executes the confirmation operation to the communication terminal, by which the transfer of the first encryption key from the communication terminal to the wireless station is enabled. [00861 Incidentally, the above “authentication message” is a message for letting the user confirm a correct wireless station to which the first encryption key should be transferred from the communication terminal. The content of the authentication message is outputted by the wireless station for the confirmation by the user. It should be noted that the message may have a form of “signal”.
• The message output system of the wireless station is a system for outputting the authentication message by use of a display unit, printing unit, speaker, etc.
• As explained above, the wireless access point is configured to execute the transmission of the notification data by the notification transmission system and thereby let the wireless station set its connection method, that is, to support the setting of the connection method at the wireless station. However, the wireless access point may also be configured to execute the support in a particular state only.
• In a particular case, the wireless access point may include mode switching system capable of switching the operation mode of the wireless access point to either one selected from a support mode supporting the setting of the connection method of each wireless station by executing the transmission of the notification data by the notification transmission system and a normal mode not supporting the setting of the connection method without executing the transmission of the notification data by the notification transmission system.
• By such composition, the wireless access point supports the setting of the connection method at the wireless station only when the operation mode of the wireless access point has been switched to the support mode, therefore, accidental setting of a connection method to a wireless station by the wireless access point can be avoided. This system that the connection method can be set to a wireless station at any time by letting the wireless station start the transmission of the announcement data with the operation mode of the wireless access point switched to the support mode.
• While the trigger for the switching of the operation mode by the mode switching system in this configuration is not particularly limited, the mode switching system may switch the operation mode in response to an instruction from outside.
• By such composition, the operation mode of the wireless access point can be switched explicitly from outside.
• Incidentally, the “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point, data transmitted from a communication terminal which is connected to the wireless access point to communicate data, etc.
• While the operation mode is switched to the support mode or the normal mode by each explicit instruction from outside in this composition, if the user forgets to return the operation mode from the support mode to the normal mode, there is a possibility of the aforementioned accidental setting of a connection method to a wireless station by the wireless access point.
• Optionally, the mode switching system may switch the operation mode to the normal mode when a prescribed period of time has passed since the switching of the operation mode to the support mode.
• By such composition, even if the user forgets to return the operation mode from the support mode to the normal mode, the operation mode can automatically be returned to the normal mode when a prescribed period of time has passed.
• Further optionally, the mode switching system may also be configured to switch the operation mode to the normal mode when the notification data has been transmitted by the reply notification transmission system for a prescribed number of times since the switching of the operation mode to the support mode.
• By such composition, even in the prescribed period after the switching of the operation mode to the support mode, the operation mode can be returned to the normal mode when the notification data has been transmitted by the reply notification transmission system for a prescribed number of times, that is, the support for the setting of the connection method can be provided to the prescribed number of wireless stations only.
• Therefore, by setting the “prescribed number” depending on the number of wireless stations to which the connection method should be set, accidental and needless setting of a connection method to a wireless station by the wireless access point can be avoided.
• Further optionally, the wireless station may include content judgment system and non-setting system. The content judgment system judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system. The non-setting system prevents the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system when the content judgment system judges that the content of the current settings does not require the new setting.
• In the wireless LAN system configured as above, the wireless station is allowed to set the connection method for the wireless connection to the wireless access point only when the content of the current settings requires new setting of the connection method for the wireless connection to the wireless access point.
• Incidentally, the non-setting system in this composition is a system for preventing the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system, and its composition for the prevention of the setting is not limited particularly. For example, the non-setting system may be configured to suspend the operation of one or more of the system, discard data received from the wireless access point, etc.
• Still optionally, the wireless station includes content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system. The announcement transmission system is configured to transmit the announcement data in a state specifying the result of the judgment by the content judgment system on the necessity of the new setting of the connection method. The notification transmission system of the wireless access point transmits the notification data only when the announcement data received from the wireless station is data capable of specifying that the new setting of the connection method is necessary.
• In the wireless LAN system configured as above, the wireless access point is allowed to set the connection method to the wireless station only when the content of the current settings of the wireless station requires new setting of the connection method, by transmitting the notification data.
• Incidentally, the cases where the “content of the current settings requires new setting of the connection method” judged by the content judgment system in the above composition include, for example, cases where the current settings regarding the connection method is the initial settings (factory shipment state), cases where part of settings necessary for the wireless connection does not exist (unregistered), etc.
• According to another aspect of the invention, there is provided a wireless LAN System in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point.
• Specifically, the wireless access point includes reply request system and method notification system. The reply request system transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods. The method notification system transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system. Meanwhile, the wireless station includes reply transmission system and method setting system. The reply transmission system transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received. The method setting system sets the connection method of the wireless station for the wireless connection to the wireless access point to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply data by the reply transmission system.
• In the wireless LAN system composed as above, the wireless access point transmits the reply request data to the wireless station according to each of the connection methods. The reply request data is received by wireless stations to which the same connection method has been set, and the wireless stations receiving the reply request data return reply data to the wireless access point in response to the reply request data. Subsequently, the wireless access point which received the reply data notifies the wireless stations of the connection method preset to the wireless access point itself by use of the notification data. Each wireless station which received the notification sets the connection method notified by the notification data (which is the same as the connection method set to the wireless access point) to itself. The connection method of each wireless station is set to the connection method identical with that of the wireless access point as above, by which the wireless connection between the wireless access point and the wireless station becomes possible.
• As above, in the wireless station, the connection method for the wireless connection to the wireless access point is set automatically by the method setting system via the reply by the reply transmission system. Therefore, the load on the user for the settings of the wireless LAN can be reduced dramatically.
• Incidentally, the “connection method” system a method of wireless connection which is specified by, for example, a wireless LAN standard (IEEE802.11b, -a, -g, etc.) employed for the wireless connection, a frequency range (the so-called “channel”) employed in the wireless LAN standard, etc.
• In the wireless access point described above, the method notification system is a system for transmitting the notification data to the wireless station when the reply data is received from the wireless station. The notification data is transmitted according to the same connection method as the received reply data (that is, the connection method set to the wireless station).
• The method notification system may be configured to transmit a request reminder data, for reminding the wireless station to request permission for wireless connection, to the wireless station as the notification data, and thereafter transmit an association reply, giving the wireless station permission for the wireless connection, to the wireless station when an association request as data for requesting the permission for the wireless connection is received from the wireless station.
• By such composition, the wireless connection between the wireless access point and the wireless station can be realized via the exchange of the association request and the association reply, after the setting of the connection method is made by the wireless station.
• In the wireless access point described above, the reply request system is a system for transmitting the reply request data according to each of the connection methods, and its composition for the transmission of the reply request data is not limited.
• For example, in cases where the wireless access point includes method switching system which switches the connection method of the wireless access point to each of the connection methods in turn at preset time intervals and thereafter returns the connection method to the connection method preset to the wireless access point, the reply request data may be transmitted according to each connection method switched and set by the method switching system on each switching of the connection method by the method switching system. In this case, the method notification system may transmit the notification data according to the connection method set at the point of the reception of the reply data when the reply data is received between the transmission of the reply request data by the reply request system and the switching of the connection method to the next connection method by the method switching system.
• By such composition., the wireless access point is allowed to transmit the reply request data according to each connection method by switching the connection method in turn. The notification data can be transmitted according to the connection method set to the wireless station transmitting the reply data, only by transmitting the notification data according to the connection method set at the point of the transmission of the reply request data.
• In this composition, while the timing for the method switching system of the wireless access point to start the switching of the connection method is not particularly limited, the method switching system may be configured to start the switching when an instruction from outside is received.
• By such composition, the setting of the connection method to the wireless station can be ordered explicitly from outside.
• Incidentally, the “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point, data transmitted from a communication terminal which is connected to the wireless access point to communicate data, etc.
• The reply request system may also be configured to transmit the reply request data according to the connection method preset to the wireless access point before the switching of the connection method by the method switching system is started.
• By such composition, the wireless connection between the wireless access point and the wireless station can be established immediately in cases where the wireless station has initial settings identical with the connection method preset to the wireless access point, by which needless switching of the connection method by the wireless access point can be avoided.
• In this composition, since the transmission of the reply request data according to the connection method preset to the wireless access point is carried out at the beginning, it is preferable that the method switching system be configured not to switch the connection method to the preset connection method.
• In the wireless station described above, the method setting system is a system for setting the connection method for the wireless connection to the wireless access point, and its composition for the setting of the connection method is not limited particularly. For example, in cases where the wireless station includes notification collection system which collects the notification data transmitted according to the connection method preset to the wireless station for a prescribed period of time, the method setting system may be configured to set a connection method notified by the notification data having the highest reception level among the notification data collected by the notification collection system as the connection method of the wireless station for the wireless connection to the wireless access point, after the collection of the notification data by the notification collection system is finished.
• By such composition, the connection method notified by the notification data having the highest reception level (among the notification data collected (received) during the prescribed period) can be set as the connection method of the wireless station for the wireless connection to the wireless access point.
• Incidentally, the notification collection system in this composition is a system for collecting the notification data. The notification data collected by the notification collection system may be stored in memory, etc. so that the correspondence of the notification data with, for example, the source (i.e. the wireless access point transmitting the notification data), the connection method and the reception level of the notification data can be specified. In this case, the method setting system may be configured to switch the connection method to a connection method corresponding to notification data of the highest reception level based on the stored correspondences.
• Such setting of the connection method (for the connection to the wireless access point) specified by the notification data having the highest reception level is advantageous for preventing erroneous setting of the connection method of the wireless station to a false connection method different from the method for the connection to the correct wireless access point.
• When the connection method (for the connection to the wireless access point) is set to the wireless station, if another wireless access point having the reply request system and the method notification system also exists in the vicinity of the wireless station (e.g. in an adjacent residence), notification data is sent also from the (other) wireless access point to the wireless station and thus there is a possibility that a connection method identical with the method set to the (other) wireless access point might be set to the wireless station regardless of the user's intention, depending on the timing of the reception of notification data.
• However, since the connection method specified by the notification data of the highest reception level can be set as the connection method for the connection to the wireless access point as mentioned above, the erroneous connection method setting based on the notification data from other wireless access points can be avoided only by putting the wireless station and the wireless access point sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
• While the method notification system of the wireless access point can transmit the notification data when the reply data is received regardless of the content of the reply data, the method notification system may also be configured to transmit the notification data to wireless stations returning the reply data satisfying a prescribed condition.
• By such composition, the wireless access point is allowed to set the connection method only to wireless stations returning the reply data satisfying the prescribed condition, by transmitting the notification data.
• While the content of the “prescribed condition” in this configuration is not particularly limited, “(reply data of) the highest reception level” may be employed as the condition, for example.
• For this, the wireless access point may include reply collection system which collects the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started, and the method notification system may transmit the notification data to a wireless station returning reply data having the highest reception level among the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station returning the reply data having the highest reception level, by transmitting the notification data.
• Therefore, erroneous transmission of the notification data to a false wireless station (different from the wireless station to which the connection method should be set) and erroneous connection method setting to the false wireless station can be avoided only by putting the wireless station and the wireless access point sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
• Incidentally, the reply collection system in this composition is a system for collecting the reply data after the transmission of the reply request data is started. The reply data collected by the reply collection system may be stored in memory, etc. so that the correspondence of, for example, the source (transmitter), the connection method and the reception level of the reply data can be specified. In this case, the method notification system may be configured to transmit the notification data according to a connection method corresponding to the highest reception level based on the stored correspondences.
• The method notification system of the wireless access point maybe configured to transmit the notification data to a wireless station returning reply data that is selected from all the reply data, returned after the transmission of the reply request data by the reply request system is started, based on an instruction from outside.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station returning the reply data that is selected based on the instruction from outside, by transmitting the notification data.
• The wireless access point may include reply collection system which collects the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started, and the method notification system may transmit the notification data to a wireless station returning reply data that is selected from all the reply data collected by the reply collection system based on an instruction from outside after the collection of the reply data by the reply collection system is finished.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station capable of returning the reply data that is selected from all the reply data (collected during the prescribed period of time) based on the instruction from outside, by transmitting the notification data.
• Incidentally, the reply collection system in this composition collects the reply data for a prescribed period of time after the transmission of the reply request data is started, as mentioned above. The reply data collected by the reply collection system may be stored in memory, etc. so that the connection method and the source of the reply data, for example, can be identified. In this case, the method notification system transmits the notification data to the wireless station returning reply data that is selected from all the collected reply data based on the instruction from outside.
• The “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point. For this, a configuration described below is possible.
• That is, the wireless access point may include first user selection system which lets a user select one or more wireless stations from the wireless stations returning the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished. The method notification system transmits the notification data to the one or more wireless stations selected by the user through the first user selection system.
• By such composition, the wireless access point is allowed to set the connection method only to the one or more wireless stations arbitrarily selected by the user, by transmitting the notification data.
• For using a particular operation by the user as the “instruction from outside”, a configuration as follows is possible.
• Namely, the reply transmission system of the wireless station transmits the reply data associating identification data for identifying the wireless station with the reply data. Meanwhile, the reply collection system of the wireless access point collects the reply data together with the identification data associated with the reply data. The wireless access point includes second user selection system which lets a user select one or more pieces of the identification data from the identification data associated with the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished. The method notification system transmits the notification data to one or more wireless stations identified by the identification data selected by the user through the second user selection system.
• By such composition, the wireless access point is allowed to set the connection method only to the one or more wireless stations identified by (associated with) the identification data arbitrarily selected by the user, by transmitting the notification data.
• Alternatively, the method notification system of the wireless access point is configured to determine the wireless station to which the notification data should be transmitted according to an instruction from a communication terminal which is connected to the wireless access point to communicate data.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless station returning the reply data that is selected (from the reply data collected during a prescribed period of time) based on the instruction from the communication terminal, by transmitting the notification data.
• In this composition, the communication of the instruction with the communication terminal can be realized by, for example, a configuration as follows.
• That is, the wireless access point may include reply collection system and listing transmission system. The reply collection system collects the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started and thereby stores data indicating correspondence between the collected reply data and wireless stations which transmitted the collected reply data in a storage unit. The listing transmission system transmits listing data, representing a list of wireless stations whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the wireless stations is received from the communication terminal. After the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more wireless stations selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the method notification system transmits the notification data to the one or more wireless stations represented by the selection data. The communication terminal includes listing request system, third user selection system and selection transmission system. The listing request system transmits the listing request data to the wireless access point. The third user selection system lets a user select one or more wireless stations from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system. The selection transmission system transmits the selection data, representing the one or more pieces of identification data selected by the user through the third user selection system, to the wireless access point.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless stations arbitrarily selected by the user of the communication terminal based on the correspondences collected by the reply collection system, by transmitting the notification data.
• The reply collection system in this configuration collects the reply data for a prescribed period of time after the transmission of the reply request data is started, as mentioned above. The reply data collected by the reply collection system may be stored in memory, etc. so that the connection method and the source of the reply data, for example, can be identified. In this case, the method notification system transmits the notification data to the wireless station returning reply data that is selected from all the collected reply data based on the instruction from outside.
• Optionally, the reply transmission system of the wireless station may transmit the reply data associating identification data for identifying the wireless station with the reply data. The wireless access point includes reply collection system and listing transmission system. The reply collection system collects the reply data together with the identification data associated with the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started and thereby stores data indicating correspondence between the identification data and wireless stations which transmitted the collected reply data in a storage unit. The listing transmission system transmits listing data, representing a list of identification data whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the identification data is received from the communication terminal. After the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more pieces of the identification data selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the method notification system transmits the notification data to one or more wireless stations corresponding to the one or more pieces of identification data represented by the selection data. The communication terminal includes listing request system, fourth user selection system and selection transmission system. The listing request system transmits the listing request data to the wireless access point. The fourth user selection system lets a user select one or more pieces of the identification data from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system. The selection transmission system transmits the selection data, representing the one or more wireless stations selected by the user through the fourth user selection system, to the wireless access point.
• By such composition, the wireless access point is allowed to set the connection method only to the wireless stations corresponding to the one or more pieces of the identification data arbitrarily selected by the user of the communication terminal based on the correspondences collected by the reply collection system, by transmitting the notification data.
• The reply collection system in this configuration collects the reply data for a prescribed period of time after the transmission of the reply request data is started, as mentioned above. The reply data collected by the reply collection system may be stored in memory, etc. so that the correspondence between the identification data and the connection method corresponding to the reply data (or the reply data itself), for example, can be identified. In this case, the listing transmission system transmits listing data, representing a list of identification data which can be identified by the stored correspondences, to the communication terminal.
• Each user selection system mentioned above is a system for letting the user make a selection. For example, the user is informed through a display unit, printing unit, speaker, etc. that a selection should be made from options (wireless stations, identification data) by use of an operation unit, and the user makes a selection from the options with the operation unit based on the information.
• In the wireless LAN systems described above, even if the wireless station is connected to the wireless access point by wireless connection, if the wireless access point is configured to carry out data communication employing encryption, normal data communication is generally impossible without similarly configuring the wireless station to execute the data communication employing the encryption.
• Therefore, for letting the wireless LAN system carry out data communication normally without the need of operations by the user, the wireless access point may include encryption switching system which switches an encryption method employed for the data communication with each wireless station. In cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the notification data by the method notification system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the notification data has been transmitted.
• By such composition, even if the wireless access point is configured to execute data communication employing encryption, normal data communication becomes possible without configuring the wireless station to execute the data communication employing the encryption. Therefore, the data communication between the wireless access point and the wireless station can be realized maintaining the security level of data communication of the wireless access point with other wireless stations or external networks.
• As another configuration for letting the wireless LAN system carry out data communication normally without the need of operations by the user, a configuration described below is also possible.
• Optionally, the method notification system of the wireless access point may be configured to transmit the notification data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the notification data. The wireless access point includes encryption switching system which, after the transmission of the notification data by the method notification system, switches an encryption method employed for data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key. The wireless station includes encryption setting system which, after the reception of the notification data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the notification data.
• By such composition, the wireless access point switches its encryption method to execute data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key. Meanwhile, the wireless station which received the notification data sets itself to execute the data communication with the wireless access point by encrypting data with the second encryption key. By the settings, normal data communication becomes possible between the wireless access point and the wireless station by encrypting data with the second encryption key. Therefore, the data communication between the wireless access point and the wireless station can be realized securing a certain security level while maintaining the security level of data communication of the wireless access point with other wireless stations or external networks.
• While the configurations realize data communication between the wireless access point and the wireless station even when the wireless access point is configured to execute data communication employing encryption, the security level of the data communication between the wireless access point and the wireless station is not sufficiently high since the configuration employs no encryption and the configuration may involve a possibility of a leak of the second encryption key while it is transmitted from the wireless access point to the wireless station.
• In order to increase the security level of the data communication between the wireless access point and the wireless station, a configuration can be employed, for example. In the wireless LAN system described below, the wireless station includes: encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system. The communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem. The encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.
• By such composition, the data communication between the wireless access point and the wireless station can be executed encrypting data with the first encryption key transferred from the communication terminal to the wireless station. Therefore, the data communication between the wireless access point and the wireless station can be realized with a security level equivalent to that of data communication of the wireless access point with other wireless stations or external networks.
• Since the transfer of the first encryption key is conducted by system of the public key cryptosystem, the probability of leak of the first encryption key during the transmission to the wireless station becomes low as a matter of course.
• In this configuration, when the communication terminal transfers the first encryption key to the wireless station, it is desirable that the communication terminal can confirm that the wireless station is a correct wireless station to which the first encryption key should be transferred. For this, a configuration as follows is possible, for example.
• In some cases, the encryption key transfer system of the communication terminal may be configured to transfer an authentication message or signal which indicates transferring of the first encryption key to the wireless station by the public key cryptosystem, and the wireless station may include a message/signal output system which outputs the authentication message or signal acquired by the encryption key acquisition system.
• That is, the encryption key transfer system of the communication terminal is configured to transfer an authentication message/signal to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key. The communication terminal includes confirmation operation system which lets a user who confirmed the authentication message/signal outputted by the wireless station carry out a confirmation operation after the authentication message/signal is transferred to the wireless station by the encryption key transfer system. The encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system. The encryption key acquisition system of the wireless station is configured to acquire the authentication message/signal which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key. The wireless station includes message/signal output system which outputs the authentication message/signal acquired by the encryption key acquisition system. The encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication message/signal outputted by the message/signal output system.
• By such composition, the user is allowed to confirm whether or not the wireless station is a correct wireless station that should receive the first encryption key from the communication terminal, by checking whether or not the authentication message is outputted by the wireless station. After confirming the authentication message outputted by the wireless station, the user executes the confirmation operation to the communication terminal, by which the transfer of the first encryption key from the communication terminal to the wireless station is enabled.
• Incidentally, the above “authentication message” is a message for letting the user confirm a correct wireless station to which the first encryption key should be transferred from the communication terminal. The content of the authentication message is outputted by the wireless station for the confirmation by the user.
• The message output system of the wireless station is a system for outputting the authentication message by use of a display unit, printing unit, speaker, etc.
• As explained above, the wireless access point is configured to execute the transmission of the notification data by the method notification system and thereby let the wireless station set its connection method, that is, to support the setting of the connection method at the wireless station. However, the wireless access point may also be configured to execute the support in a particular state only.
• Specifically, the wireless access point may include mode switching system capable of switching the operation mode of the wireless access point to either one selected from a support mode supporting the setting of the connection method of each wireless station by executing the transmission of the notification data by the method notification system and a normal mode not supporting the setting of the connection method without executing the transmission of the notification data by the method notification system.
• By such composition, the wireless access point supports the setting of the connection method at the wireless station only when the operation mode of the wireless access point has been switched to the support mode, therefore, accidental setting of a connection method to a wireless station by the wireless access point can be avoided. This system that the connection method can be set to a wireless station at any time by letting the wireless station start the transmission of the reply data with the operation mode of the wireless access point switched to the support mode.
• While the trigger for the switching of the operation mode by the mode switching system in this configuration is not particularly limited the mode switching system may switch the operation mode in response to an instruction from outside.
• By such composition, the operation mode of the wireless access point can be switched explicitly from outside.
• Incidentally, the “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point, data transmitted from a communication terminal which is connected to the wireless access point to communicate data, etc.
• While the operation mode is switched to the support mode or the normal mode by each explicit instruction from outside in this composition, if the user forgets to return the operation mode from the support mode to the normal mode, there is a possibility of the aforementioned accidental setting of a connection method to a wireless station by the wireless access point.
• Optionally, the mode switching system may switch the operation mode to the normal mode when a prescribed period of time has passed since the switching of the operation mode to the support mode.
• By such composition, even if the user forgets to return the operation mode from the support mode to the normal mode, the operation mode can automatically be returned to the normal mode when a prescribed period of time has passed.
• However, even with such composition, there still exists a possibility of the accidental setting of a connection method to a wireless station by the wireless access point in the prescribed period after the switching of the operation mode to the support mode.
• Further optionally, the mode switching system may also be configured to switch the operation mode to the normal mode when the notification data has been transmitted by the method notification system for a prescribed number of times since the switching of the operation mode to the support mode.
• By such composition, even in the prescribed period after the switching of the operation mode to the support mode, the operation mode can be returned to the normal mode when the notification data has been transmitted by the method notification system for a prescribed number of times, that is, the support for the setting of the connection method can be provided to the prescribed number of wireless stations only.
• Therefore, by setting the “prescribed number” depending on the number of wireless stations to which the connection method should be set, accidental and needless setting of a connection method to a wireless station by the wireless access point can be avoided.
• In a wireless LAN system, the wireless station may optionally include content judgment system and operation suspension system. The content judgment system judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the reply by the reply transmission system and the setting by the method setting system. The operation suspension system prevents the reply by the reply transmission system and/or the setting by the method setting system when the content judgment system judges that the content of the current settings does not require the new setting.
• In the wireless LAN system configured as above, the wireless station is allowed to set the connection method for the wireless connection to the wireless access point only when the content of the current settings requires new setting of the connection method for the wireless connection to the wireless access point.
• Incidentally, the operation suspension system in this composition is a system for preventing the reply by the reply transmission system and/or the setting by the method setting system, and its composition for the prevention of the operation (reply, setting) is not limited particularly. For example, the operation suspension system may be configured to suspend the reply operation of the reply transmission system and/or the setting operation of the method setting system.
• Further optionally, the wireless station includes content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the reply by the reply transmission system and the setting by the method setting system. The reply transmission system is configured to transmit the reply data in a state specifying the result of the judgment by the content judgment system on the necessity of the new setting of the connection method. The method notification system of the wireless access point transmits the notification data only when the reply data received from the wireless station is data capable of specifying that the new setting of the connection method is necessary.
• In the wireless LAN system configured as above, the wireless access point is allowed to set the connection method to the wireless station only when the content of the current settings of the wireless station requires new setting of the connection method, by transmitting the notification data.
• Incidentally, the cases where the “content of the current settings requires new setting of the connection method” judged by the content judgment system in the above composition include, for example, cases where the current settings regarding the connection method is the initial settings (factory shipment state), cases where part of settings necessary for the wireless connection does not exist (unregistered), etc.
• According to a further aspect of the invention, there is provided a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point.
• Specifically, the wireless access point includes announcement transmission system. The announcement transmission system transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods. Meanwhile, the wireless station includes method setting system. The method setting system sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point.
• In the wireless LAN system composed as above, the wireless access point transmits the announcement data according to each of the connection methods. The announcement data is received by wireless stations to which the same connection method has been set, and the wireless stations receiving the announcement data set their connection methods to a connection method identical with the connection method announced by the announcement data, that is, to the particular connection method set to the wireless access point. The connection method of each wireless station is set to the connection method identical with that of the wireless access point as above, by which the wireless connection between the wireless access point and the wireless station becomes possible.
• As above, in the wireless station, the connection method for the wireless connection to the wireless access point is set automatically by the method setting system via the reception of the announcement data. Therefore, the load on the user for the settings of the wireless LAN can be reduced dramatically.
• Incidentally, the “connection method” system a method of wireless connection which is specified by, for example, a wireless LAN standard (IEEE802.11b, -a, -g, etc.) employed for the wireless connection, a frequency range (the so-called “channel”) employed in the wireless LAN standard, etc.
• Optionally, the announcement transmission system of the wireless access point may transmit data for requesting a reply made according to the particular connection method, as the announcement data. The wireless access point includes connection permission system which establishes the wireless connection with the wireless station by transmitting a request reminder data for letting the wireless station request permission for the wireless connection to the wireless access point when reply data returned from the wireless station according to the announcement data is received after the transmission of the announcement data is started by the announcement transmission system and thereafter transmitting connection permission data indicating permission for the wireless connection to the wireless access point when permission request data as data for requesting the permission for the wireless connection is received from the wireless station. Meanwhile, the wireless station includes: reply system which returns the reply data representing the reply requested by the announcement data to the wireless access point according to the particular connection method announced by the announcement data when the announcement data is received from the wireless access point; and connection establishment system which establishes the wireless connection with the wireless access point via the transmission of the permission request data and the reception of the connection permission data when the request reminder data transmitted by the wireless access point is received after the reply system transmitted the reply data to the wireless access point.
• By such composition, the wireless connection between the wireless access point and the wireless station can be realized via the exchange of the permission request data and the connection permission data, after the setting of the connection method is made by the wireless station.
• In the wireless access point described above, the announcement transmission system is a system for transmitting the announcement data according to each of the connection methods, and its composition for the transmission of the announcement data is not limited particularly.
• For example, in cases where the wireless access point includes method switching system which temporarily switches the connection method of the wireless access point to each of the connection methods, the announcement data may be transmitted according to each connection method switched and set by the method switching system during each period in which the connection method is temporarily switched by the method switching system to the connection method.
• By such composition, the wireless access point is allowed to transmit the announcement data according to each connection method by temporarily switching the connection method.
• In this composition, the length of the period in which the method switching system switches the connection method from the preset connection method should be as short as possible, as long as time necessary for the transmission of the announcement data can be secured. During the period in which the connection method is changed from the preset connection method, the wireless access point generally can not carry out data communication which should be conducted according to the preset connection method. Therefore, the shortness of the period (in which the connection method is changed) is advantageous for avoiding the inconvenience of the interruption of data communication which should be conducted according to the preset connection method.
• In this composition, while the timing for the method switching system of the wireless access point to start the switching of the connection method is not particularly limited, the method switching system may be configured to start the switching when an instruction from outside is received.
• By such composition, the setting of the connection method to the wireless station can be ordered explicitly from outside.
• Incidentally, the “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point, data transmitted from a communication terminal which is connected to the wireless access point to communicate data, etc.
• Further optionally, the announcement transmission system may also be configured to transmit the announcement data according to a preset connection method before the switching of the connection method by the method switching system is started.
• By such composition, the wireless connection between the wireless access point and the wireless station can be established immediately in cases where the wireless station has initial settings identical with the connection method preset to the wireless access point.
• In this composition, since the transmission of the announcement data according to the preset connection method is carried out at the beginning, it is preferable that the method switching system be configured not to switch the connection method to the preset connection method.
• In the wireless station described above, the method setting system is a system for setting the connection method for the wireless connection to the wireless access point, and its composition for the setting of the connection method is not limited particularly. For example, in cases where the wireless station includes announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, the method setting system may be configured to set a connection method announced by announcement data having the highest reception level among the announcement data collected by the announcement collection system as the connection method of the wireless station for the wireless connection to the wireless access point, after the collection of the announcement data by the announcement collection system is finished.
• By such composition, the connection method announced by the announcement data having the highest reception level (among the announcement data collected (received) during the prescribed period) can be set as the connection method of the wireless station for the wireless connection to the wireless access point.
• Incidentally, the announcement collection system in this composition is a system for collecting the announcement data. The announcement date collected by the announcement collection system may be stored in memory, etc. so that the correspondence of the announcement data with, for example, the source (i.e. the wireless access point transmitting the announcement data), the connection method and the reception level of the announcement data can be specified. In this case, the method setting system may be configured to switch the connection method to a connection method corresponding to announcement data of the highest reception level based on the stored correspondences.
• Such setting of the connection method (for the connection to the wireless access point) specified by the announcement data having the highest reception level is advantageous for preventing erroneous setting of the connection method of the wireless station to a false connection method different from the method for the connection to the correct wireless access point.
• When the connection method (for the connection to the wireless access point) is set to the wireless station, if another wireless access point having the announcement transmission system also exists in the vicinity of the wireless station (e.g. in an adjacent residence), announcement data is sent also from the (other) wireless access point to the wireless station and thus there is a possibility that a connection method identical with the method set to the (other) wireless access point might be set to the wireless station regardless of the user's intention, depending on the timing of the reception of announcement data.
• However, since the connection method specified by the announcement data of the highest reception level can be set as the connection method for the connection to the wireless access point as mentioned above, the erroneous connection method setting based on the announcement data from other wireless access points can be avoided only by putting the wireless station and the wireless access point sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
• While the connection permission system of the wireless access point can transmit the request reminder data when the reply data is received regardless of the content of the reply data, the connection permission system may also be configured to transmit the request reminder data to wireless stations returning the reply data satisfying a prescribed condition.
• By such composition, the wireless access point is allowed to establish wireless connection only with wireless stations returning the reply data satisfying the prescribed condition, via the transmission of the request reminder data.
• While the content of the “prescribed condition” in this configuration is not particularly limited, “(reply data of) the highest reception level” may be employed as the condition, for example.
• For this, the wireless access point may include reply collection system which collects the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started, and the connection permission system may transmit the request reminder data to a wireless station returning reply data having the highest reception level among the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished.
• By such composition, the wireless access point is allowed to establish wireless connection only with the wireless station returning the reply data of the highest reception level, via the transmission of the request reminder data.
• Therefore, erroneous transmission of the request reminder data to a false wireless station (different from the wireless station with which wireless connection should be established) and erroneous establishment of the wireless connection with the false wireless station can be avoided only by putting the wireless station and the wireless access point sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
• Incidentally, the reply collection system in this composition is a system for collecting the reply data after the transmission of the announcement data is started. The reply data collected by the reply collection system may be stored in memory, etc. so that the correspondence of, for example, the source (transmitter), the connection method and the reception level of the reply data can be specified. In this case, the connection permission system may be configured to transmit the request reminder data according to a connection method corresponding to the highest reception level based on the stored correspondences.
• The connection permission system of the wireless access point may be configured to transmit the request reminder data to a wireless station returning reply data that is selected from all the reply data, returned after the transmission of the announcement data by the announcement transmission system is started, based on an instruction from outside.
• By such composition, the wireless access point is allowed to establish wireless connection only with the wireless station returning the reply data that is selected based on the instruction from outside, via the transmission of the request reminder data.
• The wireless access point may include reply collection system which collects the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started, and the connection permission system may transmit the request reminder data to a wireless station returning reply data that is selected from all the reply data collected by the reply collection system based on an instruction from outside after the collection of the reply data by the reply collection system is finished.
• By such composition, the wireless access point is allowed to establish wireless connection only with the wireless station capable of returning the reply data that is selected from all the reply data (collected during the prescribed period of time) based on the instruction from outside, via the transmission of the request reminder data.
• Incidentally, the reply collection system in this composition collects the reply data for a prescribed period of time after the transmission of the announcement data is started, as mentioned above. The reply data collected by the reply collection system may be stored in memory, etc. so that the connection method and the source of the reply data, for example, can be identified. In this case, the connection permission system transmits the request reminder data to the wireless station returning reply data that is selected from all the collected reply data based on the instruction from outside.
• The “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point. For this, a configuration described below is possible.
• In a wireless LAN system, the wireless access point may include first user selection system which lets a user select one or more wireless stations from the wireless stations returning the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished. The connection permission system transmits the request reminder data to the one or more wireless stations selected by the user through the first user selection system.
• By such composition, the wireless access point is allowed to establish wireless connection only with the one or more wireless stations arbitrarily selected by the user, via the transmission of the request reminder data.
• For using a particular operation by the user as the “instruction from outside”, a configuration described below is possible.
• That is, the reply system of the wireless station transmits the reply data associating identification data, for identifying the wireless station, with the reply data. Meanwhile, the reply collection system of the wireless access point collects the reply data together with the identification data associated with the reply data. The wireless access point includes second user selection system which lets a user select one or more pieces of the identification data from the identification data associated with the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished. The connection permission system transmits the request reminder data to one or more wireless stations identified by the identification data selected by the user through the second user selection system.
• By such composition, the wireless access point is allowed to establish wireless connection only with the one or more wireless stations identified by (associated with) the identification data arbitrarily selected by the user, via the transmission of the request reminder data.
• The “instruction from outside” in the aforementioned configuration may also mean data transmitted from a communication terminal which is connected to the wireless access point to communicate data. For this, a configuration described below is possible.
• That is, the connection permission system of the wireless access point is configured to determine the wireless station to which the request reminder data should be transmitted according to an instruction from a communication terminal which is connected to the wireless access point to communicate data.
• By such composition, the wireless access point is allowed to establish wireless connection only with the wireless station returning the reply data that is selected (from the reply data collected during a prescribed period of time) based on the instruction from the communication terminal, via the transmission of the request reminder data.
• In this composition, the communication of the instruction with the communication terminal can be realized by, for example, a configuration described below.
• That is, the wireless access point may include reply collection system and listing transmission system. The reply collection system collects the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started and thereby stores data indicating correspondence between the collected reply data and wireless stations which transmitted the collected reply data in a storage unit. The listing transmission system transmits listing data, representing a list of wireless stations whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the wireless stations is received from the communication terminal. After the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more wireless stations selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the connection permission system transmits the request reminder data to the one or more wireless stations represented by the selection data. The communication terminal includes listing request system, third user selection system and selection transmission system. The listing request system transmits the listing request data to the wireless access point. The third user selection system lets a user select one or more wireless stations from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system. The selection transmission system transmits the selection data, representing the one or more wireless stations selected by the user through the third user selection system, to the wireless access point.
• By such composition, the wireless access point is allowed to establish wireless connection only with the wireless stations arbitrarily selected by the user of the communication terminal based on the correspondences collected by the reply collection system, via the transmission of the request reminder data.
• The reply collection system in this configuration collects the reply data for a prescribed period of time after the transmission of the announcement data is started, as mentioned above. The reply data collected by the reply collection system may be stored in memory, etc. so that the connection method and the source of the reply data, for example, can be identified. In this case, the connection permission system transmits the request reminder data to the wireless station returning reply data that is selected from all the collected reply data based on the instruction from outside.
• In the composition described above, the communication of the instruction with the communication terminal can also be realized by, for example, a configuration described below.
• That is, the reply system of the wireless station transmits the reply data associating identification data, for identifying the wireless station, with the reply data. The wireless access point includes reply collection system and listing transmission system. The reply collection system collects the reply data together with the identification data associated with the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started and thereby stores data indicating correspondence between the identification data and wireless stations which transmitted the collected reply data in a storage unit. The listing transmission system transmits listing data, representing a list of identification data whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the identification data is received from the communication terminal. After the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more pieces of the identification data selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the connection permission system transmits the request reminder data to one or more wireless stations corresponding to the one or more pieces of identification data represented by the selection data. The communication terminal includes listing request system, fourth user selection system and selection transmission system. The listing request system transmits the listing request data to the wireless access point. The fourth user selection system lets a user select one or more pieces of the identification data from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system. The selection transmission system transmits the selection data, representing the one or more pieces of identification data selected by the user through the fourth user selection system, to the wireless access point.
• By such composition, the wireless access point is allowed to establish wireless connection only with the wireless stations corresponding to the one or more pieces of the identification data arbitrarily selected by the user of the communication terminal based on the correspondences collected by the reply collection system, via the transmission of the request reminder data.
• The reply collection system in this configuration collects the reply data for a prescribed period of time after the transmission of the announcement data is started, as mentioned above. The reply data collected by the reply collection system may be stored in memory, etc. so that the correspondence between the identification data and the connection method corresponding to the reply data (or the reply data itself), for example, can be identified. In this case, the listing transmission system transmits listing data, representing a list of identification data which can be identified by the stored correspondences, to the communication terminal.
• Each user selection system mentioned above is a system for letting the user make a selection. For example, the user is informed through a display unit, printing unit, speaker, etc. that a selection should be made from options (wireless stations, identification data) by use of an operation unit, and the user makes a selection from the options with the operation unit based on the information.
• In the wireless LAN systems described above, even if the wireless station is connected to the wireless access point by wireless connection, if the wireless access point is configured to carry out data communication employing encryption, normal data communication is generally impossible without similarly configuring the wireless station to execute the data communication employing the encryption.
• Therefore, for letting the wireless LAN system carry out data communication normally without the need of operations by the user the wireless access point may include encryption switching system which switches an encryption method employed for the data communication with each wireless station. In cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the request reminder data by the connection permission system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the request reminder data has been transmitted.
• By such composition, even if the wireless access point is configured to execute data communication employing encryption, normal data communication becomes possible without configuring the wireless station to execute the data communication employing the encryption. Therefore, the data communication between the wireless access point and the wireless station can be realized maintaining the security level of data communication of the wireless access point with other wireless stations or external networks.
• As another configuration for letting the wireless LAN system carry out data communication normally without the need of operations by the user, a configuration described below is also possible.
• That is, the connection permission system of the wireless access point is configured to transmit the request reminder data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the request reminder data. The wireless access point includes encryption switching system which, after the transmission of the request reminder data by the connection permission system, switches an encryption method employed for data communication with each wireless station to which the request reminder data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key. The wireless station includes encryption setting system which, after the reception of the request reminder data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the request reminder data.
• By such composition, the wireless access point switches its encryption method to execute data communication with each wireless station to which the request reminder data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key. Meanwhile, the wireless station which received the request reminder data sets itself to execute the data communication with the wireless access point by encrypting data with the second encryption key. By the settings, normal data communication becomes possible between the wireless access point and the wireless station by encrypting data with the second encryption key. Therefore, the data communication between the wireless access point and the wireless station can be realized securing a certain security level while maintaining the security level of data communication of the wireless access point with other wireless stations or external networks.
• In order to increase the security level of the data communication between the wireless access point and the wireless station, a configuration described below can be employed, for example. That is, the wireless station includes: encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system. The communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem. The encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.
• By such composition, the data communication between the wireless access point and the wireless station can be executed encrypting data with the first encryption key transferred from the communication terminal to the wireless station. Therefore, the data communication between the wireless access point and the wireless station can be realized with a security level equivalent to that of data communication of the wireless access point with other wireless stations or external networks.
• Since the transfer of the first encryption key is conducted by system of the public key cryptosystem, the probability of leak of the first encryption key during the transmission to the wireless station becomes low as a matter of course.
• In this configuration, when the communication terminal transfers the first encryption key to the wireless station, it is desirable that the communication terminal can confirm that the wireless station is a correct wireless station to which the first encryption key should be transferred. For this, a configuration described below is possible, for example.
• That is, the encryption key transfer system of the communication terminal is configured to transfer an authentication message to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key. The communication terminal includes confirmation operation system which lets a user who confirmed the authentication message outputted by the wireless station carry out a confirmation operation after the authentication message is transferred to the wireless station by the encryption key transfer system. The encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system. The encryption key acquisition system of the wireless station is configured to acquire the authentication message which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key. The wireless station includes message output system which outputs the authentication message acquired by the encryption key acquisition system. The encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication message outputted by the message output system.
• By such composition, the user is allowed to confirm whether or not the wireless station is a correct wireless station that should receive the first encryption key from the communication terminal, by checking whether or not the authentication message is outputted by the wireless station. After confirming the authentication message outputted by the wireless station, the user executes the confirmation operation to the communication terminal, by which the transfer of the first encryption key from the communication terminal to the wireless station is enabled.
• Incidentally, the above “authentication message” is a message for letting the user confirm a correct wireless station to which the first encryption key should be transferred from the communication terminal. The content of the authentication message is outputted by the wireless station for the confirmation by the user.
• The message output system of the wireless station may be a system for outputting the authentication message by use of a display unit, printing unit, speaker, etc.
• As explained above, the wireless access point is configured to execute the transmission of the announcement data by the announcement transmission system and thereby let the wireless station set its connection method, that is, to support the setting of the connection method at the wireless station. However, the wireless access point may also be configured to execute the support in a particular state only.
• Specifically, the wireless access point may include mode switching system capable of switching the operation mode of the wireless access point to either one selected from a support mode supporting the setting of the connection method of each wireless station by executing the transmission of the announcement data by the announcement transmission system and a normal mode not supporting the setting of the connection method without executing the transmission of the announcement data by the announcement transmission system.
• By such composition, the wireless access point supports the setting of the connection method at the wireless station only when the operation mode of the wireless access point has been switched to the support mode, therefore, accidental setting of a connection method to a wireless station by the wireless access point can be avoided. This system that the connection method can be set to a wireless station at any time by letting the wireless station start the reception of the announcement data with the operation mode of the wireless access point switched to the support mode.
• While the trigger for the switching of the operation mode by the mode switching system in this configuration is not particularly limited, the mode switching system may switch the operation mode in response to an instruction from outside.
• By such composition, the operation mode of the wireless access point can be switched explicitly from outside.
• Incidentally, the “instruction from outside” in this composition system, for example, a particular operation by the user to an operation unit of the wireless access point, data transmitted from a communication terminal which is connected to the wireless access point to communicate data, etc.
• While the operation mode is switched to the support mode or the normal mode by each explicit instruction from outside in this composition, if the user forgets to return the operation mode from the support mode to the normal mode, there is a possibility of the aforementioned accidental setting of a connection method to a wireless station by the wireless access point.
• Optionally, the mode switching system may switch the operation mode to the normal mode when a prescribed period of time has passed since the switching of the operation mode to the support mode.
• By such composition, even if the user forgets to return the operation mode from the support mode to the normal mode, the operation mode can automatically be returned to the normal mode when a prescribed period of time has passed.
• However, even with such composition, there still exists a possibility of the accidental setting of a connection method to a wireless station by the wireless access point in the prescribed period after the switching of the operation mode to the support mode.
• Further optionally, the mode switching system may also be configured to switch the operation mode to the normal mode when the announcement data has been transmitted by the announcement transmission system for a prescribed number of times since the switching of the operation mode to the support mode.
• By such composition, even in the prescribed period after the switching of the operation mode to the support mode, the operation mode can be returned to the normal mode when the announcement data has been transmitted by the announcement transmission system for a prescribed number of times.
• Still optionally, the wireless station may include content judgment system and operation suspension system. The content judgment system judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the setting by the method setting system. The operation suspension system prevents the setting by the method setting system when the content judgment system judges that the content of the current settings does not require the new setting.
• In the wireless LAN system configured as above, the wireless station is allowed to set the connection method for the wireless connection to the wireless access point only when the content of the current settings requires new setting of the connection method for the wireless connection to the wireless access point.
• Incidentally, the operation suspension system in this composition is a system for preventing the setting by the method setting system, and its composition for the prevention of the setting is not limited particularly. For example, the operation suspension system may be configured to suspend the setting operation of the method setting system.
• According to a further aspect of the invention, there is provided a communication terminal which functions as the wireless station for any one of the configurations of the wireless LAN system described above.
• According to another aspect of the invention, there is provided a communication terminal which functions as the wireless access point for any one of the configurations of the
• Optionally, there is provided a program for instructing a computer system to execute processes necessary for functioning as any one of the configurations described above.
• Incidentally, each communication program described above is a program composed of a sequence of instructions suitable for being processed by the computer system, for letting the computer system execute the function of each of the wireless station, the wireless access point and the communication terminal. The program is supplied to a wireless access point, wireless station or communication terminal (hereinafter referred to as a “communication terminal, etc.”), a computer system, or a user of each device via a record medium (FD, CD-ROM, memory card, etc.) or a communication network (the Internet, etc.). As the computer system for executing the program, a computer system built in a communication terminal, etc., a computer system connected with a communication terminal, etc. via a wireless/wired communication path to communicate data, etc. can be employed.
• The present invention also relates to functions equivalent to the functions explained above in relation to a wireless LAN system, a communication terminal and a computer system achieving such a system/device. The present invention also relates to a computer program comprising program code means for realizing all or part of the functions equivalent to those explained above. Such program code means may be stored on a computer-readable medium or distributed through a network and is executed by a computer when all or part of the functions is to be realized.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
• FIG. 1 is a schematic diagram showing a network configuration.
• FIG. 2 is a flowchart showing the procedure of a connection method settling process in a first embodiment.
• FIG. 3 is a sequence chart showing communication of data between an access point and a printer in the first embodiment.
• FIG. 4 is a flowchart showing the procedure of a connection method instruction process in the first embodiment.
• FIG. 5 is a flowchart showing the procedure of a connection method instruction process in a second embodiment.
• FIG. 6 is a table showing data structure of a data table.
• FIG. 7 is a flowchart showing the procedure of a connection method instruction process in a third embodiment.
• FIG. 8 is a flowchart showing the procedure of a connection method instruction process in a fourth embodiment.
• FIG. 9 is a sequence chart showing communication of data between the access point and the printer in the fourth embodiment.
• FIG. 10 is a flowchart showing the procedure of a setting instruction process in the fourth embodiment.
• FIG. 11 is a schematic diagram showing a state in which contents of listing data are displayed.
• FIG. 12 is a flowchart (No.2) showing the procedure of a setting instruction process in the fourth embodiment.
• FIG. 13 is a flowchart showing the procedure of a connection method instruction process in the fourth embodiment.
• FIG. 14 is a flowchart showing the procedure of a connection method instruction process in a fifth embodiment.
• FIG. 15 is a flowchart showing the procedure of a connection method settling process in the fifth embodiment.
• FIG. 16 is a sequence chart showing communication of data between the access point and the printer in the fifth embodiment.
• FIG. 17 is a flowchart showing the procedure of an encryption key acquisition process in the fifth embodiment.
• FIG. 18 is a flowchart showing the procedure of a setting instruction process in the fifth embodiment.
• FIG. 19 is a flowchart showing the procedure of a setting instruction process in the fifth embodiment.
• FIG. 20 is a flowchart showing the procedure of a connection method settling process in a modified embodiment.
• FIG. 21 is a flowchart showing the procedure of a setting instruction process in the modified embodiment.
• FIG. 22 is a flowchart showing the procedure of a setting instruction process in the modified embodiment.
• FIG. 23 is a flowchart (No.1) showing the procedure of a connection method instruction process in a sixth embodiment.
• FIG. 24 is a sequence chart showing communication of data between an access point and a printer in the sixth embodiment.
• FIG. 25 is a flowchart showing the procedure of a connection method setting process in the sixth embodiment.
• FIG. 26 is a flowchart (No.2) showing the procedure of a connection method instruction process in the sixth embodiment.
• FIG. 27 is a flowchart showing the procedure of a connection method setting process in a seventh embodiment.
• FIG. 28 is a flowchart showing the procedure of a connection method instruction process in a eighth embodiment.
• FIG. 29 is a flowchart showing the procedure of a connection method instruction process in a ninth embodiment.
• FIG. 30 is a flowchart showing the procedure of a connection method instruction process in a tenth embodiment.
• FIG. 31 is a sequence chart showing communication of data between the access point and the printer in the tenth embodiment.
• FIG. 32 is a flowchart showing the procedure of a setting instruction process in the tenth embodiment.
• FIG. 33 is a schematic diagram showing a state in which contents of listing data are displayed.
• FIG. 34 is a flowchart (No.2) showing the procedure of a setting instruction process in the tenth embodiment.
• FIG. 35 is a flowchart (No.2) showing the procedure of a connection method instruction process in the tenth embodiment.
• FIG. 36 is a flowchart showing the procedure of a connection method instruction process in a eleventh embodiment.
• FIG. 37 is a flowchart showing the procedure of a connection method setting process in the eleventh embodiment.
• FIG. 38 is a sequence chart showing communication of data between the access point and the printer in the eleventh embodiment.
• FIG. 39 is a flowchart showing the procedure of an encryption key acquisition process in the eleventh embodiment.
• FIG. 40 is a flowchart showing the procedure of a setting instruction process in the eleventh embodiment.
• FIG. 41 is a flowchart showing the procedure of an encryption switching process in the eleventh embodiment.
• FIG. 42 is a flowchart showing the procedure of a connection method setting process in a modified embodiment.
• FIG. 43 is a flowchart showing the procedure of a connection method instruction process in the modified embodiment.
• FIG. 44 is a flowchart (No.1) showing the procedure of a connection method instruction process in a twelfth embodiment.
• FIG. 45 is a sequence chart showing communication of data between an access point and a printer in the twelfth embodiment.
• FIG. 46 is a flowchart showing the procedure of a connection method setting process in the twelfth embodiment.
• FIG. 47 is a flowchart (No.2) showing the procedure of a connection method instruction process in the twelfth embodiment.
• FIG. 48 is a flowchart showing the procedure of a connection method setting process in a thirteenth embodiment.
• FIG. 49 is a flowchart showing the procedure of a connection method instruction process in a fourteenth embodiment.
• FIG. 50 is a flowchart showing the procedure of a connection method instruction process in a fifteenth embodiment.
• FIG. 51 is a flowchart showing the procedure of a connection method instruction process in a sixteenth embodiment.
• FIG. 52 is a sequence chart showing communication of data between the access point and the printer in the sixteenth embodiment.
• FIG. 53 is a flowchart showing the procedure of a setting instruction process in the sixteenth embodiment.
• FIG. 54 is a schematic diagram showing a state in which contents of listing data are displayed.
• FIG. 55 is a flowchart (No.2) showing the procedure of a setting instruction process in the sixteenth embodiment.
• FIG. 56 is a flowchart (No.2) showing the procedure of a connection method instruction process in the sixteenth embodiment.
• FIG. 57 is a flowchart showing the procedure of a connection method instruction process in a seventeenth embodiment.
• FIG. 58 is a flowchart showing the procedure of a connection method setting process in the seventeenth embodiment.
• FIG. 59 is a sequence chart showing communication of data between the access point and the printer in the seventeenth embodiment.
• FIG. 60 is a flowchart showing the procedure of an encryption key acquisition process in the sixth embodiment.
• FIG. 61 is a flowchart showing the procedure of a setting instruction process in the seventeenth embodiment.
• FIG. 62 is a flowchart showing the procedure of an encryption switching process in the seventeenth embodiment.
• FIG. 63 is a flowchart showing the procedure of a connection method setting process in a modified embodiment.
• FIG. 64 is a flowchart showing the procedure of a connection method instruction process in the modified embodiment.
• FIG. 65 is a flowchart showing the procedure of a connection method setting process in the modified embodiment.
• FIG. 66 is a flowchart showing the procedure of a connection method instruction process in the modified embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
• In the following, embodiments and modifications of a wireless LAN system including a plurality of network devices (hereinafter simply referred to as “devices”) connected by a LAN will be described.
Embodiment 1
• FIG. 1 shows an exemplary configuration of a wireless LAN system according to the present invention. It should be noted that a hardware configuration of the wireless LAN system is common among the embodiments and modifications described hereinafter, the wireless LAN system will be described once as a system according to the first embodiment.
• The wireless LAN system shown inFIG. 1 is composed of anaccess point10, a network printer20 (hereinafter simply referred to as a “printer”), etc.
• Theaccess point10, which is a wireless access point for relaying data communication between devices (or external networks) connected bycables100 and data communication between wireless stations, includes aCPU11, aRON12, aRAM13, anetwork controller14, awireless LAN controller15, anoperation panel16, adisplay panel17, etc.
• TheCPU11 of theaccess point10 controls the overall operation of theaccess point10 by sending instructions to the components according to a procedure stored in theROM12, while recording the results of processes in theRAM13.
• TheROM12 is a nonvolatile memory which is readable and rewritable, having storage areas for storing the SSID (Service Set IDentifier, or ESSID (Extended SSID) ) to be used when theaccess point10 itself communicates with a wireless station, parameters indicating the method of wireless connection (hereinafter referred to as “the connection method”), etc. Incidentally, the “connection method” is specified by a wireless LAN standard selected from1st through i-th wireless LAN standards (IEEE802.11a, IEEE802.11b and IEEE802.11g, for example) and a channel selected from a plurality of channels usable in the wireless LAN standard, by which the method employed by the wireless access point for realizing wireless connection with wireless stations is defined.
• Thenetwork controller14 is an interface for realizing data communication with other devices such as a PC30 (or external networks) that are connected to theaccess point10 via thecable100.
• Thewireless LAN controller15 is an interface for realizing the communication according to the wireless LAN standard based on the parameters stored in theROM12. Thewireless LAN controller15 realizes the communication function as the wireless access point by establishing a connection with a wireless station according to the connection method specified by the “parameters indicating the connection method”
• In theaccess point10 composed as above, after the “SSID” and the “parameters indicating the connection method” are stored in theROM12, wireless stations making access to theaccess point10 by an SSID identical with the SSID stored in theROM12 and by the aforementioned connection method are permitted the communication by radio.
• Incidentally, in theaccess point10, the “SSID” and the “parameters indicating the connection method” are generated and stored in theROM12 when data regarding the settings are communicated with another device by radio or by wire and the settings are made indirectly by the device (remote setup). In this embodiment, it is assumed that parameters indicating a connection method specified by a “2nd channel” of a “1st wireless LAN standard” have been stored (set) in theROM12 by the remote setup as the “parameters indicating the connection method”.
• Theprinter20, which is a device having the function of a wireless station, is provided with aCPU21, aROM22, aRAM23, awireless LAN controller24, a PC interface unit (PC I/P)25, anoperation panel26, adisplay panel27, aprint engine28, etc.
• TheCPU21 of theprinter20 controls the overall operation of theprinter20 by sending instructions to the components according to a procedure stored in theROM22, while recording the results of processes in theRAM23.
• TheROM22 is a nonvolatile memory which is readable and rewritable, having storage areas for storing the SSID to be used when theprinter20 as a wireless station communicates with the wireless access point, the parameters indicating the connection method, etc.
• Thewireless LAN controller24 is an interface for realizing the communication according to the wireless LAN standard based on the parameters stored in theROM22 similarly to thewireless LAN controller15 of theaccess point10, thewireless LAN controller24 realizes the communication function as a wireless station by establishing a connection with the wireless access point according to the connection method specified by the “parameters indicating the connection method”.
• ThePC interface unit25 is an interface for connecting theprinter20 to a PC via a communication cable, by which data communication between theprinter20 and the PC is enabled.
• In theprinter20 composed as above, after the “SSID” and the “parameters indicating the connection method” are stored in theROM22, data communication using the SSID becomes possible via a wireless connection according to the connection method. Incidentally, in theprinter20, the “SSID” and the “parameters indicating the connection method” are generated and stored (set) in theROM22 in a connection method settling process (FIG. 2) which will be explained below.
• <Connection Method Settling Process byPrinter20>
• In the following, the connection method settling process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 2. The connection method settling process is started when an operation for turning on power, restarting (resetting), initialization (returning the settings of theprinter20 to the factory shipment state and restarting), etc. is received by theoperation panel26.
• First, whether theprinter20 is in the factory shipment state or not is checked (S100). In this step, theprinter20 is judged to be in its factory shipment state if no “parameters indicating the connection method” are stored in theROM22.
• If theprinter20 is not in the factory shipment state (S100: NO), the connection method settling process is ended. If in the factory shipment state (S100: YES), a variable M is initialized (S100). In this step, a value “1” is set in the variable M (1→M). Incidentally, a character “m” in the following description system the value set in the variable M.
• Subsequently, a variable N is initialized (S120). In this step, a value “1” is set in the variable N (1→N). A character “n” in the following description system the value set in the variable N.
• Subsequently, the method of wireless connection to the wireless access point (hereinafter referred to as “connection method”) is switched to a connection method implemented by the n-th channel of the m-th wireless LAN standard (S130). In this step, the connection method employed by thewireless LAN controller24 for the wireless connection to theaccess point10 is switched by storing the parameters (for implementing a communication function by the connection method specified by the n-th channel of the m-th wireless LAN standard) in a storage area of theRAM23 for the “parameters indicating the connection method” and letting thewireless LAN controller24 control the connection method according to the memory content of theRAM23. By this, the connection method will be controlled according to the memory content of theRAM23 until next switching (for controlling the connection method according to the memory content of the ROM22) is done in a posterior step (S301). Incidentally, when the storage area for the “parameters indicating the connection method” already holds parameters, the parameters are overwritten with the new parameters.
• Subsequently, announcement data, for announcing (or advertising) the connection method switched in the step S130 to devices around theprinter20, is generated and transmitted (S140). In this step, frame data (management frame) in which a subtype (indicating that the data is announcement data) is set in the header and a device name and a device ID for identifying the device (MAC address in this embodiment) are stored in the data body is generated as the “announcement data”, and the frame data is broadcast (transmitted using a broadcast address as the destination) by a connection method based on the n-th channel of the m-th wireless LAN standard (see “ANNOUNCEMENT 11”-“ANNOUNCEMENT 3j” inFIG. 3). In a connection method instruction process (FIG. 4) which will be described later, theaccess point10 which received the announcement data returns request reminder data (see “REQUEST REMINDER” inFIG. 3) if (the content of) the announcement data has already been registered, otherwise (if the announcement data has not been registered yet) registers the announcement data without returning the request reminder data (see “ANNOUNCEMENT 12” inFIG. 3). Incidentally, the “request reminder data” is frame data which is used by theaccess point10 for reminding the wireless station (printer20) to send a request for permission for wireless connection (association request) to theaccess point10. In the request reminder data, the SSID which is used by theaccess point10 for data communication with the wireless stations is stored.
• Subsequently, a timer is started (S150). The timer started in this step will be used for checking whether or not the request reminder data is returned within a preset time limit.
• Subsequently, whether or not a timeout has occurred since the transmission of the announcement data is checked (S160). In this step, the timeout is judged to have occurred if the timer started in the step S150 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S160: NO), whether the request reminder data has been received from theaccess point10 or not is checked (S170). If the request reminder data has not been received yet (S170: NO), the process returns to the step S160.
• After repeating the steps S160 and S170, if the timeout since the transmission of the announcement data occurs (S160: YES), the timer started in the step S150 is stopped and reset (S180) and the variable N is incremented by 1 (n+1→N) (S190).
• Subsequently, whether the transmission of the announcement data has been finished by use of all the channels of the m-th wireless LAN standard or not is checked (S200). Since the number of usable channels is specified and fixed in each wireless LAN standard, the transmission of the announcement data by all the channels is judged to have finished in the step S200 if the value n of the variable N has become larger than the number (j) of usable channels of the m-th wireless LAN standard (n>j).
• If the transmission of the announcement data by all the channels of the m-th wireless LAN standard has not been finished (S200: NO), the process returns to the step S130. Thereafter, the sequence from the step S130 to the step S200 is repeated and thereby the transmission of the announcement data is successively carried out by use of each channel of the m-th wireless LAN standard (see “ANNOUNCEMENT 11”-“ANNOUNCEMENT 1j” inFIG. 3)
• After repeating the sequence from the step S130 to the step S200, if the transmission of the announcement data by all the channels of the m-th wireless LAN standard has been finished (S200: YES), the variable M is incremented by 1 (m+1→M) (S210).
• Subsequently, whether the transmission of the announcement data has been finished by use of all the wireless LAN standards or not is checked (S220). In this step, the transmission of the announcement data by all wireless LAN standards is judged to have finished if the value m of the variable M has become larger than the number (i) of wireless LAN standards that can be used by thewireless LAN controller24 for realizing communication (m>i).
• If the transmission of the announcement data by all the wireless LAN standards has not been finished (S220: NO), the process returns to the step S120.
• Thereafter, the transmission of the announcement data by use of the next wireless LAN standard is carried out by the sequence from the step S120 (see “ANNOUNCEMENT 21”-“ANNOUNCEMENT 2j” inFIG. 3). By repeating the sequence from the step S120 to the step S220, the transmission of the announcement data is successively carried out by use of all the wireless LAN standards (see “REQUEST 11”-“REQUEST ij” inFIG. 3).
• After repeating the sequence from the step S120 to the step S220, if the transmission of the announcement data by all the wireless LAN standards has been finished (S220: YES), the process returns to the step S110.
• During the repetition of the sequence from the step S120 to the step S220, if the request reminder data is received (S170: YES), the timer started in the step S150 is stopped and reset (S230) and the SSID specified by the request reminder data is stored in theRAM23 as the SSID to be used for the data communication with the wireless access point (S240). By the storage of the SSID in this step, theprinter20 becomes capable of realizing data communication with a wireless access point (access point10) that can establish communication by an SSID identical with the stored SSID.
• Subsequently, an association request for requesting permission for wireless connection is transmitted to the access point10 (S250). The “association request” is frame data (management frame) which is used for requesting permission for wireless connection to theaccess point10. In the step S250, the SSID stored in theRAM23 in the step S240 is stored in the association request and transmitted (see “ASSOCIATION REQUEST” inFIG. 3). In the header of the association request, the device ID (MAC address) of theprinter20 is stored. From theaccess point10 which received the association request, an association reply, as frame data (management frame) indicating the permission for the wireless connection to theaccess point10, is returned (see “ASSOCIATION REPLY” inFIG. 3).
• Subsequently, another timer is started (S260). The timer started in this step will be used for checking whether or not the association reply is returned within a preset time limit.
• Subsequently, whether or not a timeout has occurred since the transmission of the association request is checked (S270). In this step, the timeout is judged to have occurred if the timer started in the step S260 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S270: NO), whether the association reply has been received from theaccess point10 or not is checked (S280). If the association reply has not been received yet (S280: NO), the process returns to the step S270.
• After repeating the steps S270 and S280, if the timeout since the transmission of the association request occurs (S270: YES), the timer started in the step S260 is stopped and reset (S290) and the process returns to the step S110.
• Meanwhile, if the association reply is received in the step S280 (S280: YES), the timer started in the step S260 is stopped and reset (S300), the parameters and the SSID stored in the storage area of theRAM23 for the “parameters indicating the connection method” in the step S130 are stored in (copied to) theROM22 so that the connection method will be controlled by the memory content of the ROM22 (S301), and the connection method settling process is ended.
• At the point when the connection method settling process is ended, the switching of the connection method by the step S130 is stopped, by which the connection method at the point when the switching is stopped (m-th wireless LAN standard, n-th channel) is settled (determined) as the connection method for the wireless connection to the wireless access point.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 4. The connection method instruction process is started when an instructing operation for switching the operation mode of theaccess point10 into a “support modem” (for supporting the setting of the connection method of the wireless station) is made by the user to the operation panel16 (e.g. pressing a particular button). Incidentally, the support mode is an operation mode which is enabled only in the connection method instruction process. When the connection method instruction process is ended, the operation mode of theaccess point10 is returned from the support mode to “normal mode”.
• First, a timer is started (S310). The timer started in this step will be used for checking whether or not the announcement data is transmitted from the printer20 (step S140 ofFIG. 2) within a preset time limit after the aforementioned instructing operation. Therefore, the user sets the connection method (for the wireless connection to the access point10) to theprinter20 by letting theprinter20 start the aforementioned connection method settling process (FIG. 2) after letting theaccess point10 start this connection method instruction process (see “INSTRUCTING OPERATION” to theaccess point10 and “ACTIVATION” to theprinter20 inFIG. 3).
• Subsequently, whether or not a timeout has occurred since the start of the connection method instruction process is checked (S320). In this step, the timeout is judged to have occurred if the timer started in the step S310 has counted a preset length of time (15 sec in this embodiment).
• If the timeout has not occurred (S320: NO), whether data has been received from theprinter20 or not is checked (S330). If no data has been received yet (S330: NO), the process returns to the step S320. Incidentally, theaccess point10 can not receive and recognize data as normal data if the data has not been transmitted according to the connection method set to theaccess point10 itself (i.e. the connection method specified by the parameters stored in the ROM12). Therefore, in the step S330, whether data transmitted according to the connection method set to theaccess point10 itself (“ANNOUNCEMENT 12” inFIG. 3 in this embodiment) has been received or not is checked.
• Meanwhile, if data is received from theprinter20 in the step S330 (S330: YES) D whether the received data is the announcement data or not is checked (S340). The “announcement data” is the data which is transmitted by theprinter20 in the step S140 ofFIG. 2.
• If the received data is the announcement data (S340: YES), whether the announcement data has already been registered or not is checked (S350). In the connection method instruction process, the device name specified by the announcement data is registered in the following step (see “REGISTRATION” inFIG. 3), therefore, the announcement data is judged in the step S350 to have already been registered if the device name specified by the received announcement data has already been registered. Incidentally, the announcement data that is judged by the step S350 to have already been registered is announcement data that is received for the second time since the start of the connection method instruction process (see “ANNOUNCEMENT 12” inFIG. 3).
• If the announcement data has not been registered yet (S350: NO), the device name and the device ID specified by the announcement data are registered (e.g. registration with a data table) by storing them in a-particular storage area of the RAM13 (S360).
• Meanwhile, if the announcement data has already been registered (S350: YES), the request reminder data (for requesting the transmission of the association request) is transmitted to theprinter20 which transmitted the announcement data (S370). In this step, the “request reminder data” as frame data for requesting the transmission of the association request, containing the “SSID” stored in theROM12, is generated and transmitted to the printer20 (see “REQUEST REMINDER” inFIG. 3). The request reminder data is the data which is received by theprinter20 in the step S170 ofFIG. 2. After the reception of the request reminder data, theprinter20 transmits not the announcement data but the association request (see “ASSOCIATION REQUEST” inFIG. 3).
• After finishing the step S360 or S370, the process returns to the step S320.
• If the received data is not the announcement data in the step S340 (S340: No), whether the received data is the association request or not is checked (S380). The “association request” is the data which is transmitted by theprinter20 in the step S250 ofFIG. 2.
• If the received data is the association request in the step S380 (S380: YES), the association reply (indicating the permission for the wireless connection to the access point10) is transmitted to theprinter20 which transmitted the association request (S400) and the process returns to the step S320. The association reply is the data which is received by theprinter20 in the step S280 ofFIG. 2 (see “ASSOCIATION REPLY” inFIG. 3). In theprinter20, the connection method at the point of the reception of the association reply is set as the connection method for the wireless connection to theaccess point10.
• In this embodiment, although detailed explanation is omitted, before the exchange of the association request and association reply, an authentication request and an authentication reply are exchanged between theprinter20 and the access point10 (similarly to ordinary wireless connection procedures) after the request reminder data from theaccess point10 is received by the printer20 (see. “AUTHENTICATION REQUEST”-“AUTHENTICATION REPLY” inFIG. 3). Incidentally, since the first embodiment does not employ encryption for data communication, the exchange of the authentication request/reply is done as open authentication (authentication without encryption).
• Meanwhile, if the received data is not the association request in the step S380 (S380: NO), a process depending on the type of the received data (other process) is carried out (S410) and the process returns to the step S320.
• After repeating the sequence from the step S320 to the step S410 as above, if the timeout has occurred in the step S320 (S320: YES), the timer started in the step S310 is stopped and reset (S420) and the connection method instruction process is ended. As above, the operation mode of theaccess point10 is returned from the support mode to the normal mode with the end of the connection method instruction process.
• In the wireless LAN system composed as above, theprinter20 transmits the announcement data according to each of a plurality of connection methods while successively switching the connection method in turn (see “ANNOUNCEMENT 11”-“ANNOUNCEMENT 3j” inFIG. 3). The announcement data is received by anaccess point10 whose connection method has been set to the connection method of theprinter20 at the point of the transmission of the announcement data (see “ANNOUNCEMENT 12” inFIG. 3), and theaccess point10 notifies theprinter20 that wireless connection by use of the same connection method as the received announcement data is possible, by transmitting the request reminder data (see “REQUEST REMINDER” inFIG. 3). Theprinter20 which received the request reminder data sets the connection method notified by the request reminder data (i.e. the connection method set to the access point10) to itself. By setting theprinter20 to the same connection method as theaccess point10 as above, wireless connection between theaccess point10 and theprinter20 becomes possible.
• As above, in theprinter20, the connection method for the connection to theaccess point10 is set automatically via the switching of the connection method and the transmission of the announcement data. Therefore, the load on the user regarding the wireless LAN settings can be lightened remarkably.
• Theprinter20 successively switches the connection method in turn at preset time interval counted by the timer (steps S110-S220 inFIG. 2) and stops the connection method switching after the request reminder data is received. Only by stopping the successive switching of the connection method as above, theprinter20 can set the connection method at the point of the stop of the connection method switching (that is, the connection method set to the access point10) to itself.
• The setting of the connection method to theprinter20 can be made (the connection method settling process (FIG. 2)) by explicitly ordering from outside by activating theprinter20.
• When the connection method has been set to theprinter20, the wireless connection between theprinter20 and theaccess point10 can be realized immediately by the exchange of the association request and the association reply.
• In the connection method instruction process (FIG. 4), theaccess point10 can set the connection method to a wireless station (printer20) successively transmitting the announcement data twice according to the same connection method, by transmitting the request reminder data to the wireless station (see “REQUEST REMINDER” inFIG. 3).
• The operation mode of theaccess point10 is returned from the support mode to the normal mode when the connection method instruction process (FIG. 4) is ended when a prescribed time period has passed since the switching of the operation mode to the support mode. Therefore, the operation mode can be returned from the support mode to the normal mode automatically without the need of an operation by the user for returning the operation mode to the normal mode, by which accidental setting of a connection method to a wireless station caused by theaccess point10 left in the support mode can be prevented.
• Meanwhile, theprinter20 is capable of setting its connection method for the wireless connection to theaccess point10 only when theprinter20 is in the factory shipment state (step S100 inFIG. 2).
• Theaccess point10 collects (registers) the announcement data in the steps S340-S360 ofFIG. 4, and when announcement data transmitted from a wireless station according to the same connection method as the collected announcement data is received, transmits the request reminder data to the wireless station (step S370). Therefore, theaccess point10 can transmit the request reminder data when the announcement data is transmitted by the wireless station, that is, while the wireless station is capable of transmitting/receiving data, by which the request reminder data transmitted by theaccess point10 is received by the wireless station securely.
Modification ofEmbodiment 1
• The first embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while the process from the step S110 is executed only when theprinter20 is in its factory shipment state (S100 ofFIG. 3), it is also possible to configure theprinter20 to execute the process from the step S110 even if it is not in the factory shipment state, in cases where the setting of the connection method is necessary (e.g. when part of the “parameters indicating the connection method” stored in theROM22 is lacking).
• While the association request and association reply are exchanged after the exchange of the authentication request and authentication reply in the above embodiment, it is also possible to omit the authentication request/reply and carry out the exchange of the association request/reply only.
• In the above embodiment, theaccess point10 can receive data by the preset connection method only. At the point of the reception of the announcement data, theaccess point10 recognizes that the connection method announced by the announcement data is the same as the connection method which has been set to theaccess point10 itself. Therefore, the “announcement data” transmitted by theprinter20 does not contain parameters indicating the connection method. However, such parameters may also be stored in the announcement data.
• While the setting of the connection method to theprinter20 is ordered and started by the activation of theprinter20 in the above embodiment, the order can also be issued by, for example, a particular operation through the operation panel26 (see “ORDER” inFIG. 3). The order may also be issued by data which is sent from another communication terminal which is connected with theprinter20 to communicate data.
• While the operation mode of theaccess point10 is switched by the instructing operation in the above embodiment, theaccess point10 may also be configured to switch its operation mode when instructed by data which is sent from another communication terminal connected with theaccess point10 to communicate data.
• While theaccess point10 in the above embodiment is configured to transmit the request reminder data repeatedly until the timeout occurs in the connection method instruction process (by the return from the step S370 to the step S320), theaccess point10 may also be configured to end the connection method instruction process (specifically, advance to the step S420) after the transmission of the request reminder data. In this case, even in the prescribed time period after the switching of the operation mode to the support mode, the operation mode can be returned to the normal mode when the request reminder data is transmitted once. Therefore, the support for the setting of the connection method can be provided only to the same number of wireless stations as the number of transmission (1) of the request reminder data. In this configuration, theaccess point10 may count the number of transmission of the request reminder data and advance to the step S420 when the count has reached a prescribed number. In this case, theaccess point10 may transmit the request reminder data and switch its operation mode to the normal mode immediately after the reception of announcement data from a wireless station, without carrying out the registration of the announcement data.
• While theprinter20 in the above embodiment checks whether its in the factory shipment state or not (S100 inFIG. 2) just after starting the connection method settling process and then executes the process from the step S110, the timing of the check on the factory shipment state is not limited to the point just after the start of the connection method settling process. For example, the check may be executed between the steps S240 and S250.
• While special-purpose frame data are employed as the “announcement data” and the “request reminder data” in the above embodiment, data of known type specified in the wireless LAN standards may also be employed as the “announcement data” and the “request reminder data”. Possible data include the probe request and probe reply. However, when the probe request and probe reply are employed, theprinter20 might respond to a probe reply from a wireless access point other than theaccess point10 and establish wireless connection without distinction, by which the establishment of the wireless connection with theaccess point10 might become difficult. Such a state is not desirable for ensuring network security. Therefore, it is desirable to configure theaccess point10 to transmit a probe reply containing parameters explicitly indicating that the setting of theprinter20 will be made as the “request reminder data” when a probe request transmitted as the “announcement data” is received, and configure theprinter20 to make the setting only when the probe reply (containing the parameters explicitly indicating that the setting will be made) is received as the “request reminder data”.
Embodiment 2
• A wireless LAN system in accordance with a second embodiment of the present invention is composed similarly to the system of the first embodiment except for some steps executed by theaccess point10, therefore, only the point of difference will be explained below.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 6. The connection method instruction process is configured by replacing part (sequence from the step S350) of the connection method instruction process in the first embodiment (FIG. 4) with the following procedure. In the following explanation, steps identical with those of the first embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• If the announcement data has not been registered yet in the step S350 (S350: NO), parameters specified by the announcement data are registered (e.g. registration with a data table) by storing them in a particular storage area of the RAM13 (S352). The step S352 is similar to the step S360 inFIG. 4; however, not only the device name and the device ID but also the reception level (radio field intensity) when the announcement data was received are registered in the step S352 associating them with one another.FIG. 5 shows an example of a data table with which the parameters specified by the announcement data are registered.
• After finishing the step S352, or if the announcement data has already been registered in the step S350 (S350: YES), the process returns to the step S320.
• Incidentally, at the point when the step S340 is executed, theaccess point10 transmits no request reminder data and receives no association request. Therefore, if the received data is not the announcement data in the step S340 (S340: NO), theaccess point10 returns to the step S320 after carrying out the aforementioned “other process” (S410).
• After repeating the steps S320-S410, if the timeout has occurred in the step S320 (S320: YES), the timer started in the step S310 is stopped and reset (S420).
• Subsequently, whether or not the registration of parameters has been carried out in the step S352 is checked (S510). In this step, the registration of parameters in the step S352 is judged to have been carried out if data written by the step S352 have been stored in the particular storage area of theRAM13.
• If the parameter registration has not been carried out (S510: NO), the connection method instruction process is ended. Meanwhile, if the parameter registration has been carried out (S510: YES), another timer is started (S520). The timer, started in this step will be used for checking whether or not the announcement data is transmitted again from theprinter20 within a preset time limit after the registration of the announcement data.
• Subsequently, whether or not a timeout has occurred since the registration of the announcement data is checked (S530). In this step, the timeout is judged to have occurred if the timer which was started in the step S520 has counted a preset length of time (15 sec in this embodiment).
• If the timeout has not occurred (S530: NO), whether data has been received from theprinter20 or not is checked (S540). If no data has been received (S540: NO), the process returns to the step S530.
• If data has been received from the printer20 (S540: YES), whether or not the received data is the announcement data or not is checked (S550). This step is a step similar to the step S340 ofFIG. 4.
• If the received data is the announcement data (S550: YES), whether the announcement data has already been registered or not is checked (S560). This step is a step similar to the step S350 ofFIG. 4.
• If the announcement data has not been registered yet (S560: NO), the process returns to the step S530.
• Meanwhile, if the announcement data has already been registered (S560: YES), whether the reception level in the parameters which have been registered regarding the announcement data is the highest reception level among all the parameters or not is checked (S570).
• If the reception level is not the highest (S570: NO), the process returns to the step S530. If the reception level is the highest (S570: YES), the request reminder data is transmitted (S370) and the process returns to the step S530.
• In the step S550, if the received data is not the announcement data (S550: NO), whether the received data is the association request or not is checked (S380).
• If the received data is the association request (S380: YES), the association reply (indicating the permission for the wireless connection to the access point10) is transmitted to theprinter20 which transmitted the association request (S400) and the process returns to the step S530.
• Meanwhile, if the received data is not the association request (S380: NO), the aforementioned “other process” depending on the type of the received data is carried out similarly to the step S410 (S580) and the process returns to the step S530.
• After repeating the sequence from the step8530, if the timeout has occurred in the step S530 (S530: YES), the timer started in the step S520 is stopped and reset (S590) and the connection method instruction process is ended.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the first embodiment.
• Theaccess point10 is capable of setting the connection method to the wireless station transmitting the announcement data of the highest reception level by transmitting the request reminder data to the wireless station (steps S570 and S370 inFIG. 6).
Modification ofEmbodiment 2
• The second embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while the step S570 judges whether or not the reception level in the parameters registered regarding the received announcement data is the highest reception level among all the parameters, the step S570 may also be configured to judge whether or not the device ID in the parameters registered regarding the received announcement data is identical with the device ID at the point of the reception of the announcement data in the step S540. In this case, even when the same announcement data as the registered announcement data is received, theaccess point10 cancels the transmission of the request reminder data and the setting of the connection method if the device ID specified by the received announcement data is not identical with the device ID on the previous registration of the announcement data. By this, a wireless station trying to illicitly establish wireless connection with theaccess point10 by forging announcement data registered with theaccess point10 and transmitting the announcement data can be prevented from the wireless connection.
Embodiment 3
• A wireless LAN system in accordance with a third embodiment of the present invention is composed similarly to the system of the second embodiment except for some steps executed by theaccess point10, therefore, only the point of difference will be explained below.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 7. The connection method instruction process is configured by adding steps S512 and S514 (explained below) after the step S510 of the connection method instruction process of the second embodiment (FIG. 6) and replacing the step S570 with a step S562 (explained below), therefore, only the procedure different from the second embodiment will be described in detail.
• If the parameter registration has been carried out in the step S510 (S510: YES), the user is notified of each device name represented by the parameter registered for each announcement data (S512). In this step, the notification is executed by displaying a list of device names represented by the registered parameters on thedisplay panel17. After the list is displayed on thedisplay panel17, the user can carry out a selection operation, for selecting one or more device names from the list, through theoperation panel16.
• The selection operation is waited for until it is made by the user (S514: NO).
• When the selection operation is made (S514: YES), the process advances to the step S520. Incidentally, to each parameter corresponding to each device name selected by the selection operation, a selection flag indicating the selection by the selection operation is set (initial value “0” is turned into “1”).
• In the step S560, if the received announcement data has already been registered (S560: YES), whether the selection flag has been set to the parameter which has been registered regarding the announcement data or not is checked (S562) instead of executing the step S570.
• If the selection flag has been set (S562: YES), the process advances to the step S370, otherwise (S562: NO), the process returns to the step S530.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the second embodiment.
• Theaccess point10 is capable of setting the connection method only to the wireless station(s) (e.g. printer20) having the device name arbitrarily selected by the user, by transmitting the request reminder data (see steps S512, S514 and S562 inFIG. 7).
Modification of Embodiment 3
• The third embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while the selection operation in the steps S512 and S514 ofFIG. 7 is carried out by the user based on device names, the selection operation may also be conducted based on-device IDs instead of the device names. In this case, the connection method can be set only to wireless station(s) having the device ID(s) arbitrarily selected by the user.
Embodiment 4
• A wireless LAN system in accordance with a fourth embodiment of the present invention is composed similarly to the system of the third embodiment. The fourth embodiment is configured so that the notification of device names and the selection operation (steps S512 and S514) carried out by theaccess point10 in the third embodiment can be executed by a commonly used computer system30 (hereinafter referred to as a “PC 30”) which is connected to theaccess point10 to communicate data via acable100.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 8. The connection method instruction process is configured by replacing the steps S512 and S514 of the connection method instruction process of the third embodiment (FIG. 7) with steps S516 and S518 which will be explained below, therefore, only the procedure different from the third embodiment will be described in detail. The connection method instruction process is started after start instruction data is received from the PC30 (see “START INSTRUCTION” inFIG. 9).
• If the parameter registration has been carried out in the step S510 (S510: YES), listing data, representing the list of the device names specified by the registered parameters, is generated and transmitted to the PC30 (the device which transmitted the start instruction data) (S516). ThePC30 which received the listing data (see “LISTING DATA” inFIG. 9) displays the list represented by the listing data on its display, by which the user is informed of the device names. Thereafter, when the selection operation (for selecting one or more device names from the device names on the list) is made by the user, selection data which can specify the selected device name(s) is transmitted to the access point10 (see “SELECTION DATA” inFIG. 9).
• After the transmission of the listing data in the step S516, reception of the selection data is waited for (S518: NO). When the selection data is received (S518: YES), the process advances to the step S520. Incidentally, in the step S370 executed later, the transmission of the request reminder data to wireless stations is carried out according to parameters (SSID, connection method) associated with the device name(s) specified by the selection data received in the step S518.
• <Setting Instruction Process byPC30>
• In the following, a setting instruction process which is conducted by thePC30 will be described referring toFIG. 10. The setting instruction process is executed according to a program installed in thePC30.
• First, the start instruction data is transmitted to the access point10 (S610). Theaccess point10 which received the start instruction data starts the aforementioned connection method instruction process ofFIG. 8 (see “START INSTRUCTION” inFIG. 9) and transmits the aforementioned listing data after a while.
• The listing data from theaccess point10 is waited for until it is received (S620: NO).
• When the listing data is received (S620: YES), the content of the listing data is displayed on the display of the PC30 (S630). After the list of device names represented by the listing data is displayed (seeFIG. 11), the user can make the selection operation (for selecting one or more device names) by use of a keyboard, mouse, etc.
• The selection operation is waited for until it is made by the user (S640: NO). When the selection operation is made (S640: YES), the selection data which can specify the device name(s) selected by the selection operation is generated and transmitted to the access point10 (S650).
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the third embodiment.
• Theaccess point10 is capable of setting the connection method only to the wireless station(s) (e.g. printer20) having the device name(s) specified by the selection data received from the PC30 (i.e. the device name(s) arbitrarily selected by the user from the registered device names) by transmitting the request reminder data to the wireless station(s) (see steps S516, S518 and S562 ofFIG. 8).
Modification of Embodiment 4
• The fourth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while theaccess point10 generates the listing data which represents the list of device names in the steps S516 and S518 ofFIG. 8, theaccess point10 may also be configured to generate and transmit listing data that represents a list of device IDs and thereby let the user of thePC30 carry out the selection operation based on the device IDs instead of the device names. In this case, the connection method can be set only to the wireless station(s) having the device ID arbitrarily selected by the user of thePC30 by transmitting the request reminder data to the wireless station(s).
• While theaccess point10 registers (collects) the parameters for a prescribed time period and thereafter transmits the listing data generated based on the collected parameters in the above embodiment, theaccess point10 may also be configured to generate and the transmit the listing data at the point when a request for transmission is received from the PC30 (see “LISTING REQUEST” inFIG. 9). For this configuration, a step for waiting for an operation requesting the listing data (step S612) is added between the steps S610 and S620 ofFIG. 10 and a step for requesting (the transmission of) the listing data in response to the above operation (step S614) is added after the step S612 as shown inFIG. 12, and a step for waiting for the request from the PC30 (step S515) is added between the steps S510 and S516 ofFIG. 8 as shown inFIG. 13, for example. Also in this configuration, the selection operation may also be carried out based on the device IDs instead of the device names, similarly to the configuration mentioned above.
• It is also possible in the above embodiment to configure theaccess point10 to notify thePC30 that the connection method has been set (or will be set) to the wireless station after theaccess point10 has transmitted the request reminder data to the wireless station (printer20). For this configuration, a step for transmitting setting notification data (for the notification of the execution of the setting) to the PC30 (S402) is added after the step S400 ofFIG. 8 as shown inFIG. 13, and a step for waiting for the setting notification data (S652) and a step for notifying the user that the connection method has been set to the wireless station in response to the reception of the setting notification data (S654) are added after the step S650 ofFIG. 10 as shown inFIG. 12, for example.
Embodiment 5
• In the embodiments described above, even if theprinter20 is connected to theaccess point10 by wireless connection, if theaccess point10 is configured to carry out data communication employing encryption, normal data communication is generally impossible without similarly configuring theprinter20 to execute the data communication employing the encryption. Therefore, the wireless LAN system of this embodiment is designed for letting the wireless LAN systems of the above described embodiments carry out data communication normally without the need of operations by the user.
• First, if a “parameter regarding security” is stored in theROM12, theaccess point10 starts executing communication with security measures based on the parameter. As the “parameter regarding security”, an encryption key for carrying out the communication in an encrypted state (e.g. WEP (wired Equivalent Privacy) key in this embodiment) can be employed for example. If an encryption key has been stored in theROM12, the access point10 (CPU11) carries out the communication with the wireless station by encrypting data with the encryption key. Incidentally, the encryption key is generated and stored in theROM12 by the aforementioned remote setup.
• Meanwhile, if a “parameter regarding security” is stored in theROM22, theprinter20 starts executing communication with security measures based on the parameter. As the “parameter regarding security”, an encryption key can be employed similarly to the case of theaccess point10. If an encryption key has been stored in theROM22, the printer20 (CPU21) carries out the communication with the wireless access point by encrypting data with the encryption key.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 14. The connection method instruction process is configured by adding a step S372 (explained below) after the step S370 of the connection method instruction process of the fourth embodiment (FIG. 8) and adding steps S592, S594 and S596 (explained below) after the step S590, therefore, only the procedure different from the fourth embodiment will be described in detail.
• In the step S370 in this embodiment, an encryption key that is different from the ordinary encryption key stored in the ROM12 (hereinafter referred to as a “tentative encryption key”) is generated randomly, and a request reminder data to which the tentative encryption key is attached is transmitted.
• Before returning to the step S530 after transmitting the request reminder data in the step S370, the device name and the device ID of the wireless station to which the request reminder data was transmitted are registered with a reminder list associating them with the tentative encryption key attached to the request reminder data in the step S370 (S372). The “reminder list” is a data table which is generated in theRAM13 for the registration of the data.
• After finishing the step S590, the release of wireless connection with any one of the wireless stations registered with the reminder list in the step S372 is waited for (S592: NO). When the wireless connection is released (S592: YES), the information registered with the reminder list regarding the wireless station corresponding to the released wireless connection is deleted (S594).
• After finishing the step S594, whether there exists registered information remaining in the reminder list or not is checked (S596). If there remains registered information (S596: YES), the process returns to the step S592. The judgment is repeated and when the reminder list is empty (S596: NO), the connection method instruction process is ended.
• <Connection Method Settling Process byPrinter20>
• In the following, a connection method setting process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 15. The connection method settling process is configured by adding the following procedure to the connection method settling process of the previous embodiments (FIG. 2). In the following explanation, steps identical with those of the previous embodiments will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• After receiving the request reminder data in the step S170, the SSID specified by the request reminder data is stored in theROM22 and the tentative encryption key is stored in a storage area of theRAM23 for the “parameter regarding security” (S174). Thereafter, by switching the connection method in the step S224, data communication with the wireless access point (access point10) is carried out by encrypting data with the tentative encryption key stored in the storage area for the “parameter regarding security”.
• After finishing the step S301, the encryption key of theaccess point10 is acquired (S700). The step S700 is a step for acquiring the encryption key of theaccess point10 from thePC30 by system of the public key cryptosystem (see “ENCRYPTION KEY (ENCRYPTED BY RANDOM NUMBER)” inFIG. 16). Details of the step S700 will be explained later in an explanation of an encryption key acquisition process (FIG. 17).
• If the encryption key is acquired successfully in the step S700 (S302: YES), the encryption key is stored in the ROM22 (S304). In this step, in addition to the storage of the encryption key in theROM22, deletion of the tentative. encryption key from theRAM23 is executed.
• Subsequently, the wireless connection with theaccess point10 is released (S306). In this step, the wireless connection with theaccess point10 is released by transmitting an authentication release message to the access point10 (see “AUTHENTICATION RELEASE” inFIG. 16).
• Subsequently, the wireless connection with theaccess point10 is reestablished (S308). In this step, the wireless connection is reestablished by exchanging the authentication request/reply with theaccess point10 similarly to the aforementioned procedure. After the wireless connection is established by this step, data communication is executed by encrypting data with the encryption key stored in theROM22 in the step S304.
• After the step S308, or if the encryption key has not been acquired in the step S302 (S302: NO), the connection method settling process is ended.
• <Encryption Key Acquisition Process byPrinter20>
• In the following, an encryption key acquisition process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 17. The encryption key acquisition process is the details of the step S700 ofFIG. 15.
• First, a public key and a private key used for the public key cryptosystem as a pair are generated (S710).
• Subsequently, the public key generated in the step S710 is transmitted to the PC30 (S720). In this step, data of the public key is transmitted to thePC30 as a prescribed device. ThePC30 which received the public key encrypts a random number (which is generated randomly) by the public key and transmits the encrypted random number to theprinter20. ThePC30 further transmits prescribed print data (representing a prescribed message image) encrypted by the random number to theprinter20.
• Theprinter20 receives the encrypted random number from the PC30 (S730), receives the encrypted print data from the PC30 (S740), decrypts the message image (represented by the print data received in the step S740) by the public key generated in the step S710, and lets theprint engine28 print the message image (S750). The message image printed in this step contains a message for letting the user confirm that the random number received in the step S730 was transmitted by thePC30 certainly to theprinter20 itself. The user who confirmed the fact conducts a confirmation operation (which will be described later in an explanation of a setting instruction process (FIG. 18)) by use of thePC30. After the confirmation operation, the encryption key encrypted in the step S730 will be transmitted from thePC30 to theprinter20.
• A timer is started (S760) and whether the encryption key has been received or not is checked (S770). If the encryption key has been received (5770: YES), the timer which was started in the step S760 is stopped and reset (S780) and the encryption key acquisition process is ended.
• On the other hand, if the encryption key has not been received (S770: NO), whether a timeout has occurred or not is checked (S790). In this step, the timeout is judged to have occurred if the timer started in the step S760 has counted a preset length of time (30 sec in this embodiment).
• If the timeout has not occurred (S790: NO), the process returns to the step S770. If the timeout has occurred (S790: YES), the process advances to the step S780. by which the encryption key acquisition process is ended without acquiring the encryption key.
• <Setting Instruction Process byPC30>
• In the following, a setting instruction process which is conducted by thePC30 will be described referring toFIG. 18. The setting instruction process is executed according to a program installed in thePC30. The setting instruction process is configured by adding the following procedure after the step S650 of the setting instruction process of previous embodiments (FIG. 10). In the following explanation, steps identical with those of the previous embodiments will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• After the step S650 is finished, the public key transmitted from theprinter20 is waited for until it is received (S810: NO). The public key is the data which is transmitted by theprinter20 in the step S720 ofFIG. 17.
• When the public key is received (S810: YES), a random number (generated randomly) is encrypted by the public key and the encrypted random number is transmitted to theprinter20. The encrypted random number is the data which is received by theprinter20 in the step S770 ofFIG. 17.
• Subsequently, the print data representing the message image is encrypted by the random nubmer received in the step S810 and the encrypted print data is transmitted to the printer20 (S830). The encrypted print data is the data which is received by theprinter20 in the step S740 ofFIG. 17. Theprinter20 which received the print data prints the message image, and the user conducts the confirmation operation to thePC30 after the message image is printed out, as mentioned above. The confirmation operation is done by pressing a particular key/button, pressing keys/buttons in a particular order, etc.
• The confirmation operation is waited for until it is done by the user (S840: NO).
• When the confirmation operation is conducted (S840: YES), the encryption key is encrypted by the random number generated in the step S820 and the encrypted encryption key is transmitted to the printer20 (S850). The encrypted encryption key is the data which is received by theprinter20 in the step S770 ofFIG. 17. Incidentally, the encryption key is data which has previously been stored in memory, etc.
• After finishing the step S850, the setting instruction process is ended.
• <Encryption Switching Process byAccess Point10>
• Theaccess point10 is configured to execute an encryption switching process when the time of data communication (transmission/reception of data) with a wireless station has come since its activation. In the following, the encryption switching process will be described referring toFIG. 19.
• First, whether the wireless station (to carry out data communication with) is a wireless station having a device name or device ID registered with the reminder list of theRAM13 or not is checked (S910).
• If the wireless station is one having a device name or device ID registered with the reminder list (S910: YES), data communication is carried out by encrypting data with a tentative encryption key corresponding to the device name or device ID (S920).
• On the other hand, if the wireless station is one having no device name nor device ID registered with the reminder list (S910: NO), ordinary data communication is carried out by encrypting data with the encryption key (S930).
• After finishing the steps S920 or S930 as above, the encryption switching process is ended.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the previous embodiments.
• For a wireless station to which the request reminder data has been transmitted, theaccess point10 switches its encryption method so as to execute data communication encrypting data with the tentative encryption key (see S910 inFIG. 19). Meanwhile, theprinter20 which received the request reminder data sets its encryption method so as to execute the data communication with theaccess point10 encrypting data with the tentative encryption key (see S224 inFIG. 15). By the procedure, normal data communication between theaccess point10 and theprinter20 encrypting data with the tentative encryption key becomes possible, by which the data communication between theaccess point10 and theprinter20 can be realized ensuring a certain security level while maintaining the security level of data communication of theaccess point10 with external networks.
• Subsequently, if theprinter20 successfully acquires the encryption key by the encryption key acquisition process (FIG. 17), theprinter20 reestablishes the wireless connection with the access point10 (see steps S306 and S308 inFIG. 15), by which the data communication between theaccess point10 and theprinter20 will thereafter be carried out by encrypting data with the encryption key transferred from thePC30 to theprinter20. In theaccess point10, the parameters regarding the wireless station corresponding to the released wireless connection are deleted from the reminder list at this point (see step S594 inFIG. 14), by which the encryption method of theaccess point10 is returned so as to execute the data communication with theprinter20 encrypting data with the encryption key. Therefore, the data communication between theaccess point10 and theprinter20 can be realized with a security level equivalent to that of data communication of theaccess point10 with other wireless stations or external networks.
• Since the transfer of the encryption key from thePC30 to theprinter20 is conducted by system of the public key cryptosystem, the probability of leak of the encryption key during the transmission to theprinter20 becomes low as a matter of course.
• Further, theprinter20 prints the message image represented by the print data transferred from thePC30 prior to the encryption key (see step S750 inFIG. 17). Thus, the user is allowed to confirm whether or not theprinter20 is a correct wireless station that should receive the encryption key from thePC30, by checking whether or not the message image is printed by theprinter20. After confirming the message image, the user executes the confirmation operation to the PC30 (see step S840 inFIG. 18), by which the transfer of the encryption key from thePC30 to theprinter20 is enabled.
• [Modifications]
• While the present invention has been described with reference to the above particular illustrative embodiments, the present invention is not to be restricted by those embodiments but can also be implemented in various configurations.
• For example, while aprinter20 is employed in the above embodiments as the wireless station of the present invention, any type of device capable of operating as a wireless station can be employed as the wireless station of the present invention.
• While thePC30 is connected to theaccess point10 via thecable100 in the above embodiments, thePC30 may also be connected to theaccess point10 by wireless connection in cases where thePC30 has the wireless station function.
• While all the sequence containing the transmission of the announcement data is not executed by theprinter20 in the above embodiments when theprinter20 is judged not to be in the factory shipment state (see step S100 inFIGS. 2 and 15), it is also possible to let theprinter20 transmit the announcement data in a state allowing the judgment on the factory shipment state and let theaccess point10 cancel the registration regarding the announcement data or the transmission of the request reminder data.
• For this, in theprinter20, the step S100 is executed after the step S130 as show inFIG. 20, for example. If “YES” in the step S100, announcement data, in which an “Unconfigured device” flag is set (set to “1”), is transmitted (S142). If “NO” in the step S100, announcement data, in which the “unconfigured device” flag is not set (set to “0”), is transmitted (S944) and the process advances to the step S150.
• Meanwhile, in theaccess point10, the following procedure may be added to the processes ofFIGS. 4, 6,7,8,13 and14. For example, as shown inFIG. 21, after the step S340, if the “Unconfigured device” flag in the received announcement data indicates that the wireless station (printer20) is in its factory shipment state (S342: YES), the process advances to the step S350, otherwise (S342: NO) the process returns to the step S320. Or as shown inFIG. 22, after the step S550, if the “Unconfigured device” flag in the received announcement data indicates that the wireless station is in the factory shipment state (S552: YES), the process advances to the step S560, otherwise (S552: NO) the process returns to the step S530.
• By such a configuration, theaccess point10 is allowed to set the connection method (by carrying out the registration based on the announcement data and the transmission of the request-reminder data) only when the wireless station is in its factory shipment state.
• While theprinter20 in the above embodiment switches its connection method in numerical order starting from the 1st channel of the1st wireless LAN standard, the order of the channel switching is not particularly limited. For example, a proper order for avoiding radio wave interference in the same wireless LAN standard may also be employed.
• Specifically, the channels may be divided into a plurality of groups (e.g. a high frequency group and a low frequency group) and the channel switching may be done in turn like from a j-th channel (j: arbitrary number) of a group to a j-th channel of the next group and so forth, successively for all the channels of each group. In this case, switching to a channel of the same group (switching to a close frequency band) does not occur and thereby the radio wave interference can be avoided.
• Similarly, the channel switching may also be done in turn at intervals of a preset channel number k (e.g. at intervals of 5 channels) starting from the 1st channel, repeating the sequence starting from the 2nd channel and so forth to a sequence starting from the k-th channel. In this case, the radio wave interference can be avoided securely by setting the interval sufficiently wide so as to eliminate the radio wave interference.
• In the above-described fifth embodiment, by printing a message (image) transmitted from thePC30, the user can confirm that theprinter20 is the correct wireless station that is to receive the encryption key from thePC30. This can be modified such that a preliminary stored image corresponding to the signal transmitted from thePC30 may be printed. Alternatively, corresponding to the received signal, a message may be displayed on thedisplay panel27, LEDs (not shown) may be lit, predetermined sound (e.g., voice message) may be output from the speaker. Further alternatively, instead of printing the image, temperature of a component may be increased or smoke is discharged.
Embodiment 6
• A wireless LAN system in accordance with a sixth embodiment will be described hereinafter. It should be noted that a hardware configuration of the wireless LAN system according to the sixth embodiment is similar to that shown inFIG. 1 and the description there of is omitted for the brevity.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 23. The connection method instruction process is started when an instructing operation for switching the operation mode of theaccess point10 into a “support mode” (for supporting the setting of the connection method of the wireless station) is made by the user to the operation panel16 (e.g. pressing a particular button). Incidentally, the support mode is an operation mode which is enabled only in the connection method instruction process. When the connection method instruction process is ended, the operation mode of theaccess point10 is returned from the support mode to “normal mode”.
• First, a variable M is initialized (S1110). In this step, a value “1” is set in the variable M (1→M). Incidentally, a character “m” in the following description system the value set in the variable M.
• Subsequently, a variable N is initialized (S1120). In this step, a value “1” is set in the variable N (1→N). A character “n” in the following description system the value set in the variable N.
• Subsequently, the method of wireless connection to the wireless station (hereinafter referred to as “connection method”) is switched to a connection method implemented by the n-th channel of the m-th wireless LAN standard (S1130). In this step, the connection method employed by thewireless LAN controller15 is switched by storing the parameters (for implementing a communication function by the connection method specified by the n-th channel of the m-th wireless LAN standard) in a storage area of theRAM13 for the “parameters indicating the connection method” and letting thewireless LAN controller15 control the connection method according to the memory content of theRAM13. By this, the connection method will be controlled according to the memory content of theRAM13 until next switching (for controlling the connection method according to the memory content of the ROM12) is done in a posterior step (S1250). Incidentally, when the storage area for the “parameters indicating the connection method” already holds parameters, the parameters are overwritten with the new parameters.
• Subsequently, a probe request is broadcast (transmitted using a broadcast address as the destination) (S1140). The “probe request” is well-known frame data which is transmitted by the wireless access point for inquiring whether there exists a wireless station located nearby the wireless access point. In this embodiment, the probe request is transmitted for the purpose of supporting the setting of the connection method of wireless stations (see “REQUEST 11”-“REQUEST 3j” inFIG. 24). From theprinter20 which received the probe request, a probe reply is returned in the connection method setting process (FIG. 25) which will be explained later (see “REPLY” inFIG. 24).
• Subsequently, a timer is started (S1150). The timer started in this step will be used for checking whether or not the probe reply is returned within a preset time limit from a wireless station (printer20) that should support the wireless connection setting.
• Subsequently, whether the probe reply has been returned from a wireless station or not is checked (S1160).
• If no probe reply has been returned (S1160: NO), whether or not a timeout has occurred since the transmission (broadcast) of the probe request is checked (S1170). In this step, the timeout is judged to have occurred if the timer which was started in the step S1150 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S1170: NO), the process returns to the step S1160. If the timeout has occurred (S1170: YES), the timer started in the step S1150 is stopped and reset (S1180) and the variable N is incremented by 1 (n+1→N) (S1190).
• Subsequently, whether the transmission of the probe request has been finished by use of all the channels of the m-th wireless LAN standard or not is checked (S1200). Since the number of usable channels is specified and fixed in each wireless LAN standard, the transmission of the probe request by all the channels is judged to have finished in the step S1200 if the value n of the variable N has become larger than the number (j) of usable channels of the m-th wireless LAN standard (n>j)
• If the transmission of the probe request by all the channels of the m-th wireless LA standard has not been finished (S1200: NO), the process returns to the step S1130. Thereafter, the sequence from the step S130 to the step S1200 is repeated and thereby the transmission of the probe request is successively carried out by use of each channel of the m-th wireless LAN standard (see “REQUEST 11”-“REQUEST 1j” inFIG. 24).
• After repeating the sequence from the step S1130 to the step S1200, if the transmission of the probe request by all the channels of the m-th wireless LAN standard has been finished (S1200: YES), the variable M is incremented by 1 (m+1→M) (S1210)
• Subsequently, whether the transmission of the probe request has been finished by use of all the wireless LAN standards or not is checked (S1220). In this step, the transmission of the probe request by all wireless LAN standards is judged to have finished if the value m of the variable M has become larger than the number (i) of wireless LAN standards that can be used by thewireless LAN controller15 for realizing communication (m>i).
• If the transmission of the probe request by all the wireless LAN standards has not been finished (S1220: NO), the process returns to the step S120.
• Thereafter, the transmission of the probe request by use of the next wireless LAN standard is carried out by the sequence from the step S1120. By repeating the sequence from the step S1120 to the step S1220, the transmission of the probe request is successively carried out by use of all the wireless LAN standards (see “REQUEST 11”-“REQUEST 3j” inFIG. 24).
• After repeating the sequence from the step S120 to the step S1220, if the transmission of the probe request by all the wireless LAN standards has been finished (S1220: YES), the process returns to the step S1110.
• During the repetition of the sequence from the step S1120 to the step S1220, if the probe reply is returned from a wireless station (S1160: YES), the timer started in the step S1150 is stopped and reset (S1230) and a request reminder data is transmitted to the wireless station that returned the probe reply (S1240). The “request reminder data” is frame data which is used for reminding the wireless station (printer20) to send a request for permission for wireless connection (association request) to theaccess point10. The request reminder data contains the SSID used by theaccess point10 for data communication with the wireless stations and the parameters indicating the connection method (the 2nd channel of the 1st wireless LAN standard) previously set to theaccess point10. Theprinter20 which received the request reminder data transmits the association request to theaccess point10 according to the same connection method as that of theaccess point10 in the connection method setting process (FIG. 25) which will be explained later.
• Subsequently, the connection method is returned to the initial settings (S1250). In this step, the “parameters indicating the connection method” stored in theRAM13 are deleted and thereafter data communication is carried out based on the “parameters indicating the connection method” stored in theROM12. The parameters stored in theROM12 are those that have been preset to theaccess point10 as the initial settings. Thus, the connection method of theaccess point10 is returned to the initial settings. Thereafter, theaccess point10 executes data communication according to the initial settings until it returns to the step S1110.
• Subsequently, another timer is started (S1260). The timer started in this step will be used for checking whether or not the association request is returned from the wireless station (printer20) within a preset time limit.
• Subsequently, whether the association request has been received from the wireless station or not is checked (S1270).
• If the association request has not been received (S1270: NO). whether or not a timeout has occurred since the transmission of the request reminder data is checked (S1280). In this step, the timeout is judged to have occurred if the timer started in the step S1260 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S1280: NO), the process returns to the step S1270. If the timeout has occurred (S1280: YES), the timer started in the step S1260 is stopped and reset (S1290) and the process returns to the step S1110.
• In the step S1270, if the association request has been received (S1270: YES), the timer is stopped and reset similarly to the step S1290 (S1300), and an association reply (permitting the wireless connection to the access point10) is transmitted to theprinter20 that returned the association request (S1310).
• As described above, the wireless connection between theaccess point10 and theprinter20 is established by the exchange of the association request and association reply.
• In this embodiment, although detailed explanation is omitted, before the exchange of the association request and association reply, an authentication request and an authentication reply are exchanged between theprinter20 and the access point10 (similarly to ordinary wireless connection procedures) after the request reminder data from theaccess point10 is received by the printer20 (see “AUTHENTICATION REQUEST”-“AUTHENTICATION REPLY” inFIG. 24). Incidentally, since the first embodiment does not employ encryption for data communication, the exchange of the authentication request/reply is done as open authentication (authentication without encryption).
• <Connection Method Setting Process byPrinter20>
• In the following, the connection method setting process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 25. The connection method setting process is started when theprinter20 is activated.
• First, whether theprinter20 itself is in the factory shipment state or not is checked (S1410). In this step, theprinter20 is judged to be in its factory shipment state if no “parameters indicating the connection method” are stored in theROM22.
• If in the factory shipment state (S1410: YES), the initial settings are made (S1420). In this step, the initial settings are made by storing parameters that have been preset as the “parameters indicating the connection method” in theROM22. In this embodiment, parameters indicating a connection method specified by the 2nd channel of the 3rd wireless LAN standard are stored in theROM22 as the “parameters indicating the connection method”.
• Subsequently, a timer is started (S1430). The timer started in this step will be used for checking whether or not data is transmitted from a wireless access point (that should set the connection method) within a preset time limit. In this embodiment, the “wireless access point that should set the connection method” system theaccess point10, and the “data” system data that is transmitted by theaccess point10 in the aforementioned connection method instruction process (FIG. 23). Therefore, the usersets the connection method (for the connection to the access point10) to theprinter20 by activating the printer20 (i.e. starting this connection method setting process) after letting theaccess point10 start the aforementioned connection method instruction process (FIG. 23) (see “INSTRUCTING OPERATION” to theaccess point10 and “ACTIVATION” to theprinter20 inFIG. 24).
• Subsequently, whether a probe request has been received from a wireless access point or not is checked (S1440). The “probe request” is well-known frame data (MAC frame) which is transmitted by the wireless access point for inquiring whether there exists a wireless station located nearby the wireless access point, that is, data transmitted (broadcast) from theaccess point10 in the step S1140 ofFIG. 23. Specifically, in the step S1440, whether a probe request according to the connection method that has been set to theprinter20 itself (i.e. the connection method that has been set as the initial settings) has been received or not is checked (see “REQUEST 11”-“REQUEST 3j” inFIG. 24).
• If a probe request has been received (S1440: YES), a probe reply is returned (S1450). The probe reply is the data which is received by theaccess point10 in the step S160 ofFIG. 23 (see “REPLY” inFIG. 24).
• After finishing the step S1450, or if no probe request has been received (S1440: NO), whether a request reminder data has been received from the wireless access point or not is checked (S1460). The request reminder data is the data which is transmitted by the access point10 (which received the probe reply transmitted in the step S1450) in the step S1240 ofFIG. 23.
• If no request reminder data has been received (S1460: NO), whether or not a timeout has occurred regarding the data reception from the wireless access point is checked (S1470). In this step, the timeout is judged to have occurred if the timer started in the step S1430 has counted a preset length of time (30 sec in this embodiment).
• If the timeout has not occurred (S1470: NO), the process returns to the step S1440.
• After repeating the sequence from the step S1440 to the step S1470, if the timeout has occurred (S1470: YES), the timer started in the step S1430 is stopped and reset (S1480), error notification is executed (S1490), and the connection method setting process is ended. In the step S1490, the user is notified of an error by an error message (indicating, for example, that there exists no wireless access point functioning normally around the printer20) displayed on thedisplay panel27.
• During the repetition of the sequence from the step S1440 to the step S1470, if a request reminder data is received (S1460: YES), the timer started in the step S1430 is stopped and reset (S1500).
• Subsequently, the connection method for the connection to the wireless access point is set based on the request reminder data received in the step S1460 (S1510). In this step, the connection method for the connection to the wireless access point is set by storing the “SSID” and the “parameters indicating the connection method” stored in the request reminder data in theROM22. By the above process, theprinter20 starts executing data communication according to the SSID and the connection method, by which data communication with theaccess point10 becomes possible.
• After finishing the step S1510, or if theprinter20 is not in the factory shipment state in the aforementioned step S1410 (S1410: NO), an association request for requesting permission for wireless connection is transmitted to the access point10 (S1520). The “association request” is frame data (management frame) for requesting wireless connection permission (permission for wireless connection) from theaccess point10. In the step S1520, the SSID which was stored in theROM22 in the step S1510 is stored in the association request and transmitted (see “ASSOCIATION REQUEST” inFIG. 24). Incidentally, in the header (header information) of the association request, the device ID of the printer20 (MAC address) is set (stored). From theaccess point10 which received the association request, an association reply, as frame data (management frame) indicating the permission for the wireless connection to theaccess point10, is returned (see “ASSOCIATION REPLY” inFIG. 24).
• Subsequently, another timer is started (S1530). The timer started in this step will be used for checking whether or not the association reply is returned within a preset time limit.
• Subsequently, whether or not a timeout has occurred since the transmission of the association request is checked (S1540). In this step, the timeout is judged to have occurred if the timer started in the step S530 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S1540: NO), whether the association reply has been received from theaccess point10 or not is checked (S1550). If the association reply has not been received (S1550: NO), the process returns to the step S1540.
• Thereafter, the steps S540 and S550 are repeated and if the timeout (since the transmission of the association request) has occurred (S1540: YES), the timer started in the step S1530 is stopped and reset (1S570), and the process returns to the step S1420.
• On the other hand, if the association reply has been received in the step S1550 (S1550: YES), the timer started in the step S1530 is stopped and reset (S1590), and the connection method setting process is ended.
• In the wireless LAN system composed as above, theaccess point10 transmits the probe request to the wireless stations (including the printer20) according to each of a plurality of connection methods (see “REQUEST” inFIG. 24). The probe request is received by theprinter20 to which the same connection method has been set (see “REQUEST” inFIG. 24), and theprinter20 returns the probe reply to theaccess point10 in response to the probe request (see “REPLY” inFIG. 24). Subsequently, theaccess point10 which received the probe reply notifies theprinter20 of the connection method (which has been set to theaccess point10 itself) by use of the request reminder data (see “REQUEST REMINDER” inFIG. 24). Theprinter20 which received the notification sets the connection method notified by the request reminder data (which is the same as the connection method set to the access point10) to itself. By setting theprinter20 to the same connection method as theaccess point10 as above, wireless connection between theaccess point10 and theprinter20 becomes possible.
• As above, in theprinter20, the connection method for the connection to theaccess point10 is set automatically via the transmission of the probe reply and the reception of the request reminder data (S450-S510 inFIG. 25). Therefore, the load on the user regarding the wireless LAN settings can be lightened remarkably.
• After the connection method has been set to theprinter20, the wireless connection between theaccess point10 and theprinter20 can be established immediately via the exchange of the association request/reply.
• Theaccess point10 transmits the probe requests while successively switching the connection method in turn at prescribed time intervals (S1110-S1220 inFIG. 23), and if a probe reply is received in a period before the switching to the next connection method (S1160), transmits the request reminder data according to the connection method at the point of the reception of the probe reply (S1240).
• As above, theaccess point10 can transmit the probe requests according to each connection method while successively switching the connection method in turn. Theaccess point10 can set the connection method (which has been preset to theaccess point10 itself) to theprinter20 only by transmitting the request reminder data according to the connection method at the point of the reception of the probe reply.
• The starting of the connection method instruction process (FIG. 23) by theaccess point10 can be ordered explicitly from outside by the instructing operation. Similarly, starting of the connection method setting process (FIG. 25) by theprinter20 can be ordered explicitly from outside by activating theprinter20.
• The setting of the connection method to theprinter20 can be executed only when theprinter20 is in its factory shipment state (S1410 ofFIG. 25).
Modification of Embodiment 6
• The six embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while the process from the step S1420 is executed only when theprinter20 is in its factory shipment state (S1410 ofFIG. 25) in the above embodiment, it is also possible to configure theprinter20 to execute the process from the step S1420 even if it is not in the factory shipment state, in cases where the setting of the connection method is necessary (e.g. when part of the “parameters indicating the connection method” stored in theROM22 is lacking). While the step S1410 judges that theprinter20 is in the factory shipment state if no “parameters indicating the connection method” are stored in theROM22, it is also possible to set a specific flag at the stage of factory shipment and use the flag for indicating the factory shipment state. In this case, theprinter20 is judged to be in the factory shipment state if the flag is still set. The flag is reset when the “parameters indicating the connection method” are stored in theROM22.
• While the association request and association reply are exchanged after the exchange of the authentication request and authentication reply in the above embodiment, it is also possible to omit the authentication request/reply and carry out the exchange of the association request/reply only.
• While the setting of the connection method to theprinter20 is ordered and started by the activation of theprinter20 in the above embodiment, the order can also be issued by, for example, a particular operation through the operation panel26 (see “ORDER” inFIG. 24).
• While the operation mode of theaccess point10 is switched by the instructing operation in the above embodiment, theaccess point10 may also be configured to switch its operation mode when instructed by data which is sent from another device capable of communicating with theprinter20.
• While theprinter20 in the above embodiment checks whether its in the factory shipment state or not (S1410 inFIG. 25) just after starting the connection method setting process and then executes the process from the step S1420, the timing of the check on the factory shipment state is not limited to the point just after the start of the connection method setting process. Before the step S1440, before the step S1510, etc. are also possible.
• While theaccess point10 in the above embodiment transmits a probe request as data for supporting the setting of the connection method of the wireless stations, data other than the probe request can also be employed as long as the same purpose can be achieved.
• While theaccess point10 in the above embodiment switches its connection method in numerical order starting from the 1st channel of the 1st wireless LAN standard, the order of the channel switching is not particularly limited. For example, a proper order for avoiding radio wave interference in the same wireless LAN standard may also be employed.
• Specifically, the,channels may be divided into a plurality of groups (e.g. a high frequency group and a low frequency group) and the channel switching may be done in turn like from a j-th channel (j: arbitrary number) of a group to a j-th channel of the next group and so forth, successively for all the channels of each group. In this case, switching to a channel of the same group (switching to a close frequency band) does not occur and thereby the radio wave interference can be avoided.
• Similarly, the channel switching may also be done in turn at intervals of a preset channel number k (e.g. at intervals of 5 channels) starting from the 1st channel, repeating the sequence starting from the 2nd channel and so forth to a sequence starting from the k-th channel. In this case, the radio wave interference can be avoided securely by setting the interval sufficiently wide so as to eliminate the radio wave interference.
• It is also possible to let theaccess point10 first conduct the process from the step S1140 with the connection method preset to itself and then repeat the same process by use of each connection method in numerical order starting from the 1st channel of the1st wireless LAN standard.FIG. 26 shows an example of such a process flow, in which steps S1101-S1105 equivalent to the steps S1140-S1180 ofFIG. 23 are added before the step S1110 ofFIG. 23. If a probe reply to the probe request transmitted according to the preset connection method is received (S1103: YES), the process advances to the step S1230. On the other hand, if a timeout occurs without receiving the probe reply (S1104: YES), the timer is stopped and reset (S1105) and the process advances to the step S1110. Preferably, a judgment step may also be provided between the steps S1190 and S1200, by which the process advances to the step S1200 only when the connection method after incrementing the variable N by 1 is not identical with the initial settings, and otherwise (when the connection method after the increment is identical with the initial settings) the process returns to the step S1190.
• By such composition, the wireless connection between theaccess point10 and theprinter20 can be established immediately in cases where theprinter20 has the initial settings identical with the connection method preset to theaccess point10, by which needless switching of the connection method by theaccess point10 can be avoided.
• While theaccess point10 returns to the step S1110 when the judgment in the step S1220 ofFIG. 23 is “YES” in the above embodiment, theaccess point10 may also end the connection method instruction process (FIG. 23) via a step (S1221) for returning its connection method to the initial settings when the judgment is “YES”, as shown inFIG. 26.
Embodiment 7
• A wireless LAN system in accordance with a seventh embodiment of the present invention is composed similarly to the system of the sixth embodiment except for some steps executed by theprinter20, therefore, only different portions will be explained below.
• <Connection Method Setting Process byPrinter20>
• In the following, the connection method setting process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 27. The connection method setting process ofFIG. 27 is configured by adding a step S482 (explained below) between the steps S1480 and S1490 of the connection method setting process in the first embodiment (FIG. 25) and replacing the step S1500 of the process with steps S1462 and S1464 (explained below), therefore, only the procedure different from the first embodiment will be described in detail. In the following explanation, steps identical with those of the sixth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• If a request reminder data has been received from theaccess point10 in the step S1460 (S1460: YES), whether the request reminder data has already been registered or not is checked (S1462). In this connection method setting process, parameters specified by the request reminder data are registered in a posterior step. Therefore, in the step S1462, the received request reminder data is judged to have already been registered if the parameters specified by the request reminder data have already been registered.
• If the request reminder data has not been registered yet (S1462: NO), the parameters specified by the request reminder data are registered, by storing the parameters in a parameter storage area of the RAM23 (S1464). In this embodiment, theaccess point10 is configured to transmit a request reminder data containing not only the SSID but also parameters indicating the device ID of theaccess point10, the connection method preset to theaccess point10, etc. in the step S1240 ofFIG. 23. In the step S1464, the parameters are registered together with a value indicating the reception level (radio field intensity) when the request reminder data was received, associating them with one another. The data structure is similar to that shown inFIG. 6, with which the parameters specified by the request reminder data are registered.
• After finishing the step S1464, or if the request reminder data has already been registered in the step S1462 (S1462: YES), the process advances to the step S1470 similarly to the case of “NO” of the step S1460.
• After finishing the steps S1470 and S1480, whether or not the registration of parameters has been carried out in the step S1464 is checked (S1482). In this step, the registration of parameters in the step S1464 is judged to have been carried out if data (data table) indicating the parameters have been stored in the parameter storage area of theRAM23.
• If the parameter registration has been carried out (S1482: YES) the process advances to the step S1510, otherwise (S1482: NO) the process advances to step S1490.
• In the step S1510, from the “parameters indicating the connection method” registered in the step S1464, a set of “parameters indicating the connection method” corresponding to the highest reception level is selected and stored in theROM22, by which the connection method is set.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the first embodiment.
• Theprinter20 is capable of setting a connection method specified by the request reminder data having the highest reception level among the request reminder data collected (registered) in a preset time period (S1464 inFIG. 27) as its connection method for the connection to the wireless access point (S510 inFIG. 27).
• Such setting of the connection method (for the connection to the wireless access point) specified by the request reminder data having the highest reception level is advantageous for preventing erroneous setting of the connection method of theprinter20 to a false connection method different from the method for the connection to the correct wireless access point.
• If another wireless access point similar to the access point10 (wireless access point) of the present invention also exists in the vicinity of the printer20 (e.g. in an adjacent residence) when the connection method (for the connection to the wireless access point) is set to theprinter20, request reminder data is sent also from the (other) wireless access point and thus there is a possibility that a connection method identical with the method set to the (other) wireless access point might be set to theprinter20 regardless of the user's intention, depending on the timing of the reception of request reminder data.
• However, since the second embodiment enables the setting of the connection method (for the connection to the wireless access point) that is specified by the request reminder data having the highest reception level as above, the erroneous connection method setting based on the request reminder data from other wireless access points can be avoided only by putting theprinter20 and theaccess point10 sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
Embodiment 8
• A wireless LAN system in accordance with a third embodiment of the present invention is composed similarly to the system of the first embodiment except for some steps executed by theaccess point10, therefore, only the point of difference will be explained below.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 28. The connection method instruction process is configured by replacing the step S1230 of the connection method instruction process of the sixth embodiment (FIG. 23) with a step S1162 which will be explained below and adding a step S1222 explained below) after the step S1220, therefore, only the procedure different from the sixth embodiment will be described in detail. In the following explanation, steps identical with those of the sixth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• If a probe reply has been received in the step S1160 (S1160: YES), parameters specified by the probe reply are registered by storing them in a parameter storage area of the RAM13 (S1162). In this embodiment, theprinter20 returns the probe reply which contains the SSID and the device ID in the step S1450 ofFIG. 25. In the step S1162, the SSID and the device ID are registered together with parameters indicating the connection method and the reception level at the point when the probe reply was received in the step. S1160, associating them with one another.
• After finishing the step S162, the process advances to the step S1170, similarly to the case of “NO” in the step S1160.
• After the steps S1170-S1220, if the judgment in the step S1220 is “YES”, whether or not the registration of parameters has been carried out in the step S1162 is checked (S1222). In this step, the registration of parameters in the step S1162 is judged to have been carried out if data indicating the parameters have been stored in the parameter storage area of theRAM13.
• If the parameter registration has been carried out in the step S1222 (S1222: YES), the process returns not to the step S1110 but to step S1240. In the step S1240, the request reminder data is transmitted to a single wireless station only, according to the SSID and the connection method corresponding to (associated with) the highest reception level that are selected from the parameters registered in the step S1162.
• On the other hand, if the parameter registration has not been carried out in the step S1222 (S1222: NO), the connection method instruction process is ended.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the first embodiment.
• Theaccess point10 is capable of setting the connection method to the wireless station returning the probe reply of the highest reception level by transmitting the request reminder data to the wireless station.
• Therefore, erroneous transmission of the request reminder data to a different wireless station (different from the wireless station (printer20) to which the connection method should be set) and the setting of the connection method to the different wireless station can be avoided only by putting theaccess point10 and theprinter20 sufficiently in the vicinity of each other for gaining enough reception level during the radio communication similarly to the seventh embodiment.
Modification ofEmbodiment 8
• The eighth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• While theaccess point10 transmits the request reminder data to the wireless station returning the probe reply of the highest reception level in the step S1240 ofFIG. 28, theaccess point10 may also be configured to transmit the request reminder data to any wireless stations returning the probe reply of a reception level higher than a threshold level in the step S1240.
Embodiment 9
• A wireless LAN system in accordance with a ninth embodiment of the present invention is composed similarly to the system of the sixth embodiment except for some steps executed by theaccess point10, therefore, only the point of difference will be explained below.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 29. The connection method instruction process is configured by adding steps S1224 and S1226 (explained below) after the step S1222 of the connection method instruction process of the eighth embodiment (FIG. 28), therefore, only the procedure different from the sixth embodiment will be described in detail. In the following explanation, steps identical with those of the eighth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• In this embodiment, theprinter20 returns the probe reply which contains the SSID, a device name and the device ID in the step S1450 ofFIG. 25. In the step S1162 of the connection method instruction process of this embodiment, the SSID, the device name and the device ID are registered together with parameters indicating the connection method and the reception level at the point when the probe reply was received in the step S1160, associating them with one another.
• Afterward, if the parameter registration has been carried out in the step S1222 (S1222: YES), a device name list containing the parameters registered in the step S162 is displayed on thedisplay panel17 in order to inform-the user of the device names. After the list is displayed on thedisplay panel17, the user can make a selection of a device name from the device names on the list (selection operation) through theoperation panel16.
• The selection operation is waited for until it is made by the user (S1226: NO).
• When the selection operation is made (S1226: YES), the process advances to the step S240. Incidentally, to the parameter corresponding to the device name selected by the selection operation, a selection flag indicating the selection by the selection operation is set (initial value “0” is turned into “1”).
• In the step S1240, the request reminder data is transmitted to the selected wireless station, according to the parameters (SSID and connection method) to which the selection flag has been set (i.e. parameters selected from the parameters registered in the step S1162).
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the third embodiment.
• Theaccess point10 is capable of setting the connection method only to the wireless station having the device name that is arbitrarily selected by the user (e.g. printer20) by transmitting the request reminder data to the wireless station (steps S1224, S1226 and S1240 inFIG. 29).
Modification of Embodiment 9
• The ninth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• While the selection operation by the user in the steps S1224 and S1226 ofFIG. 29 is carried out based on the device names, the selection operation may also be carried out based on the device IDs instead of the device names. In this case, the connection method can be set to the wireless station having the device ID arbitrarily selected by the user by transmitting the request reminder data to the wireless station only.
Embodiment 10
• A wireless LAN system in accordance with a tenth embodiment of the present invention is composed similarly to the system of the ninth embodiment. The tenth embodiment is configured so that the notification of device names and the selection operation (carried out by theaccess point10 in the fourth embodiment) can be executed by a commonly used computer system30 (hereinafter referred to as a “PC30”) which is connected to theaccess point10 to communicate data via a cable100 (seeFIG. 1).
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 30. The connection method instruction process is configured by replacing the steps S1224 and S1226 of the connection method instruction process of the fourth embodiment (FIG. 29) with steps S1228 and S1229 which will be explained below, therefore, only the procedure different from the fourth embodiment will be described in detail. The connection method instruction process is started after start instruction data is received from the PC30 (see “START INSTRUCTION” inFIG. 31).
• If the parameter registration has been carried out in the step S1222 (S1222: YES), listing data, representing the list of the device names specified by the registered parameters, is generated and transmitted to the PC30 (the device which transmitted the start instruction data) (S1228). ThePC30 which received the listing data (see “LISTING DATA” inFIG. 31) displays the list represented by the listing data on its display, by which the user is informed of the device names. Thereafter, when the selection operation (for selecting a device name from the device names on the list) is made by the user, selection data which can specify the selected device name is generated and transmitted to the access point10 (see “SELECTION DATA” inFIG. 31).
• After the transmission of the listing data in the step S1228, reception of the selection data is waited for (S1229: NO). When the selection data is received (S1229: YES), the process advances to step S1240.
• In the step S1240, the request reminder data is transmitted to the selected wireless station according to the parameters (SSID and connection method) corresponding to (associated with) the device name specified by the selection data received in the step S1229.
• <Setting Instruction Process byPC30>
• In the following, a setting instruction process which is conducted by thePC30 will be described referring toFIG. 32. The setting instruction process is executed according to a program installed in thePC30.
• First, the start instruction data is transmitted to the access point10 (S1610). Theaccess point10 which received the start instruction data starts the aforementioned connection method instruction process ofFIG. 30 (see “START INSTRUCTION” inFIG. 31) and transmits the aforementioned listing data after a while.
• The listing data from theaccess point10 is waited for until it is received (S1620: NO).
• When the listing data is received (S1620: YES), the content of the listing data is displayed on the display of the PC30 (S1630). After the list of device names represented by the listing data is displayed (seeFIG. 33), the user can make the selection operation (for selecting a device name) by use of a keyboard, mouse, etc.
• The selection operation is waited for until it is made by the user (S1640: NO). When the selection operation is made (S1640: YES), the selection data which can specify the device name selected by the selection operation is generated and transmitted to the access point10 (S1650). Theaccess point10 which received the selection data (see “SELECTION DATA” inFIG. 31) transmits the request reminder data to the wireless station having the device name specified by the selection data (see “REQUEST REMINDER” inFIG. 31).
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the ninth embodiment.
• Theaccess point10 is capable of setting the connection method only to the wireless station (e.g. printer20) having the device name that is specified by the selection data received from the PC30 (i.e. the device name that is arbitrarily selected by the user from the device names which have been registered based on the probe replies) by transmitting the request reminder data to the wireless station.
Modification ofEmbodiment 10
• The tenth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while theaccess point10 generates the listing data which represents the list of device names in the step S1228 ofFIG. 30, theaccess point10 may also be configured to generate and transmit listing data that represents a list of device IDs, let the user of thePC30 carry out the selection operation based on the device IDs instead of the device names, and transmit the request reminder data to the selected wireless station according to the parameters (SSID and connection method) corresponding to (associated with) the selected device ID in the step S1240. In this case, the connection method can be set only to the wireless station having the device ID arbitrarily selected by the user of thePC30 by transmitting the request reminder data to the wireless station.
• While theaccess point10 registers (collects) the parameters for a prescribed time period and thereafter transmits the listing data generated based on the collected parameters in the above embodiment, theaccess point10 may also be configured to generate and the transmit the listing data at the point when a request for transmission is received from the PC30 (see “LISTING REQUEST” inFIG. 31). For this configuration, a step for waiting for an operation requesting the listing data (step S1612) is added between the steps S1610 and S1620 ofFIG. 32 and a step for requesting (the transmission of) the listing data in response to the above operation (step S1614) is added after the step S1612 as shown inFIG. 34, and a step for waiting for the request from the PC30 (step S1223) is added between the steps S1222 and51228 ofFIG. 30 as shown inFIG. 35, for example. Also in this configuration, the selection operation may also be carried out based on the device IDs instead of the device names, similarly to the configuration mentioned above.
• It is also possible in the above embodiment to configure theaccess point10 to notify thePC30 that the connection method has been set (or will be set) to the wireless station after theaccess point10 has transmitted the request reminder data to the wireless station (printer20). For this configuration, a step for transmitting setting notification data (for the notification of the execution of the setting) to the PC30 (S1312) is added after the step S1310 ofFIG. 30 as shown inFIG. 35, and a step for waiting for the setting notification data (S1652) and a step for notifying the user that the connection method has been set to the wireless station in response to the reception of the setting notification data (S1654) are added after the step S1650 ofFIG. 32 as shown inFIG. 34, for example.
Embodiment 11
• In the embodiments described above, even if theprinter20 is connected to theaccess point10 by wireless connection, if theaccess point10 is configured to carry out data communication employing encryption, normal data communication is generally impossible without similarly configuring theprinter20 to execute the data communication employing the encryption. Therefore, the wireless LAN system of this embodiment is designed for letting the wireless LAN system of the above tenth embodiment carry out data communication normally without the need of operations by the user.
• First, if a “parameter regarding security” is stored in theROM12, theaccess point10 starts executing communication with security measures based on the parameter. As the “parameter regarding security”, an encryption key for carrying out the communication in an encrypted state. (e.g. WEP (Wired Equivalent Privacy) key in this embodiment) can be employed for example. If an encryption key has been stored in theROM12, the access point10 (CPU11) carries out the communication with the wireless station by encrypting data with the encryption key. Incidentally, the encryption key is generated and stored in theROM12 by the aforementioned remote setup.
• Meanwhile, if a “parameter regarding security” is stored in theROM22, theprinter20 starts executing communication with security measures based on the parameter. As the “parameter regarding security”, an encryption key can be employed similarly to the case of theaccess point10. If an encryption key has been stored in theROM22, the printer20 (CPU21) carries out the communication with the wireless access point by encrypting data with the encryption key.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 36. The connection method instruction process is configured by adding steps S1314, S1316 and S1318 (explained below) after the step S310 of the connection method instruction process of the fifth embodiment (FIG. 30), therefore, only the procedure different from the fifth embodiment will be described in detail.
• In the step S1240 in this embodiment, an encryption key that is different from the ordinary encryption key stored in the ROM12 (hereinafter referred to as a “tentative encryption key”) is generated randomly, and a request reminder data to which the tentative encryption key is attached is transmitted to the wireless station.
• After finishing the sequence to the step S1310 after transmitting the request reminder data in the step S1240, the device name and the device ID of the wireless station (to which the request reminder data was transmitted in the step S1240) are registered with a reminder list associating them with the tentative encryption key attached to the request reminder data in the step S1240 (S1314). The “reminder list” is a data table which is generated in theRAM13 for the registration of the data.
• The release of the wireless connection with the wireless station registered with the reminder list in the step S1314 is waited for (S1316: NO). When the wireless connection is released (S1316: YES), the information registered with the reminder list is deleted (S1318) and the connection method instruction process is ended.
• <Connection Method Settling Process byPrinter20>
• In the following, a “connection method settling process” which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 37. The connection method settling process is a process configured by adding a sequence explained below after the step S580 of the connection method setting process of the fifth embodiment (FIG. 27). In the following explanation, steps identical with those of the fifth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• First, after receiving the request reminder data in the step S1460, the SSID specified by the request reminder data is stored in theROM22 and the tentative encryption key is stored in a storage area of theRAM23 for the “parameter regarding security” in the step S1464. Thereafter, the connection method is set in the step S1510, by which the data communication with the wireless access point (access point10) is carried out by encrypting data with the tentative encryption key stored in the storage area for the “parameter regarding security”.
• After finishing the step S1580, the encryption key of theaccess point10 is acquired (S1700). The step S1700 is a step for acquiring the encryption key of theaccess point10 from thePC30 by means of the public key cryptosystem (see “ENCRYPTION KEY (ENCRYPTED BY RANDOM NUMBER)” inFIG. 38). Details of the step S1700 will be explained later in an explanation of an encryption key acquisition process (FIG. 39).
• If the encryption key is acquired successfully in the step S1700 (S1592: YES), the encryption key is stored in the ROM22 (S1584). In this step, in addition to the storage of the encryption key in theROM22, deletion of the tentative encryption key from theRAM23 is executed.
• Subsequently, the wireless connection with theaccess point10 is released (S1586). In this step, the wireless connection with theaccess point10 is released by transmitting an authentication release message to the access point10 (see “AUTHENTICATION RELEASE” inFIG. 38).
• Subsequently, the wireless connection with theaccess point10 is reestablished (S1588). In this step, the wireless connection is reestablished by exchanging the authentication request/reply with theaccess point10 similarly to the aforementioned procedure. Incidentally, the exchange of the authentication request/reply in this step is carried out by means of shared key authentication (based on encryption) using the encryption key transferred to theprinter20. After the wireless connection is established by this step, data communication is executed by encrypting data with the encryption key rewritten in the step S1584.
• After the step S5188, or if the encryption key has not been acquired in the step S1582 (S1582: NO), the connection method settling process is ended.
• <Encryption Key Acquisition Process byPrinter20>
• In the following, an encryption key acquisition process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 39. The encryption key acquisition process is the details of the step S1700 ofFIG. 37.
• First, a public key and a private key used for the public key cryptosystem as a pair are generated (S1710).
• Subsequently, the public key generated in the step. S1710 is transmitted to the PC30 (S1720). In this step, data of the public key is transmitted to thePC30 as a prescribed device. ThePC30 which received the public key encrypts a random number (which is generated randomly) by the public key and transmits the encrypted random number to theprinter20. ThePC30 further transmits prescribed print data (representing a prescribed message image) encrypted by the random number to the printer20 (see “RANDOM NUMBER (ENCRYPTED BY PUBLIC KEY)” and “PRINT DATA (ENCRYPTED BY RANDOM NUMBER)” inFIG. 38).
• Theprinter20 receives the encrypted random number from the PC30 (S1730), receives the encrypted print data from the PC30 (S1740), decrypts the message image (represented by the print data received in the step S1740) by the public key generated in the step S710, and lets theprint engine28 print the message image (S1750). The message image printed in this step contains a message for letting the user confirm that the random number received in the step S730 was transmitted by thePC30 certainly to theprinter20 itself. The user who confirmed the fact conducts a confirmation operation (which will be described later in an explanation of a setting instruction process (FIG. 40)) by use of thePC30. After the confirmation operation, the encryption key encrypted in the step S1770 will be transmitted from thePC30 to theprinter20.
• A timer is started (S1760) and whether the encryption key has been received or not is checked (S1770). If the encryption key has been received (S1770: YES), the timer which was started in the step S1760 is stopped and reset (S1780) and the encryption key acquisition process is ended.
• On the other hand, if the encryption key has not been received (S1770: NO), whether a timeout has occurred or not is checked (S1790). In this step, the timeout is judged to have occurred if the timer started in the step S1760 has counted a preset length of time (30 sec in this embodiment).
• If the timeout has not occurred (S1790: NO), the process returns to the step S1770. If the timeout has occurred (S1790: YES), the process advances to the step S1780. by which the encryption key acquisition process is ended without acquiring the encryption key.
• <Setting Instruction Process byPC30>
• In the following, a setting instruction process which is conducted by thePC30 will be described referring toFIG. 40. The setting instruction process is executed according to a program installed in thePC30. The setting instruction process is configured by adding the following procedure after the step S1650 of the setting instruction process of the tenth embodiment (FIG. 32) In the following explanation, steps identical with those of the tenth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• After the step S1650 is finished, the public key transmitted from theprinter20 is waited for until it is received (S1810: No). The public key is the data which is transmitted by theprinter20 in the step S1720 ofFIG. 39.
• When the public key is received (S1810: YES), a random number (generated randomly) is encrypted by the public key and the encrypted random number is transmitted to theprinter20. The encrypted random number is the data which is received by theprinter20 in the step S1730 ofFIG. 39.
• Subsequently, the print data representing the message image is encrypted by the random number received in the step S1810 and the encrypted print data is transmitted to the printer20 (S1830). The encrypted print data is the data which is received by theprinter20 in the step S1740 ofFIG. 39. Theprinter20 which received the print data prints the message image, and the user conducts the confirmation operation to thePC30 after the message image is printed out, as mentioned above. The confirmation operation is done by pressing a particular key/button, pressing keys/buttons in a particular order, etc.
• The confirmation operation is waited for until it is done by the user (S1840: NO).
• When the confirmation operation is conducted (S1840: YES), the encryption key is encrypted by the random number generated in the step S1820 and the encrypted encryption key is transmitted to the printer20 (S1850). The encrypted encryption key is the data which is received by theprinter20 in the step S1770 ofFIG. 39. Incidentally, the encryption key is data which has previously been stored in memory, etc.
• After finishing the step S850, the setting instruction process is ended.
• <Encryption Switching Process byAccess Point10>
• Theaccess point10 is configured to execute an encryption switching process when the time of data communication (transmission/reception of data) with a wireless station has come since its activation. In the following, the encryption switching process will be described referring to FIG.41.
• First, whether the wireless station (to carry out data communication with) is a wireless station having a device name or device ID registered with the reminder list of theRAM13 or not is checked (S1910).
• If the wireless station is one having a device name or device ID registered with the reminder list (S1910: YES), data communication is carried out by encrypting data with a tentative encryption key corresponding to the device name or device ID (S1920).
• On the other hand, if the wireless station is one having no device name nor device ID registered with the reminder list (S1910: NO), ordinary data communication is carried out by encrypting data with the encryption key (S1930).
• After finishing the steps S1920 or S1930 as above, the encryption switching process is ended.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the previous embodiments.
• For a wireless station to which the request reminder data has been transmitted, theaccess point10 switches its encryption method so as to execute data communication encrypting data with the tentative encryption key (S1910 inFIG. 41). Meanwhile, theprinter20 which received the request reminder data sets its encryption method so as to execute the data communication with theaccess point10 encrypting data with the tentative encryption key (S1510 inFIG. 37). By the procedure, normal data communication between theaccess point10 and theprinter20 encrypting data with the tentative encryption key becomes possible, by which the data communication between theaccess point10 and theprinter20 can be realized ensuring a certain security level while maintaining the security level of data communication of theaccess point10 with external networks.
• Subsequently, if theprinter20 successfully acquires the encryption key by the encryption key acquisition process (FIG. 39), theprinter20 reestablishes the wireless connection with the access point10 (see steps S1586 and S1588 inFIG. 37), by which the data communication between theaccess point10 and theprinter20 will thereafter be carried out by encrypting data with the encryption key transferred from thePC30 to theprinter20. In theaccess point10, the information registered with the reminder list is deleted at this point (see step S1318 inFIG. 36), by which the encryption method of theaccess point10 is returned so as to execute the data communication with theprinter20 encrypting data with the encryption key. Therefore, the data communication between theaccess point10 and theprinter20 can be realized with a security level equivalent to that of data communication of theaccess point10 with other wireless stations or external networks.
• Since the transfer of the encryption key from thePC30 to theprinter20 is conducted by means of the public key cryptosystem, the probability of leak of the encryption key during the transmission to theprinter20 becomes low as a matter of course.
• Further, theprinter20 prints the message image represented by the print data transferred from thePC30 prior to the encryption key (see step S1750 inFIG. 39). Thus, the user is allowed to confirm whether or not theprinter20 is a correct wireless station that should receive the encryption key from thePC30, by checking whether or not the message image is printed by theprinter20. After confirming the message image, the user executes the confirmation operation to the PC30 (see step S1840 inFIG. 40), by which the transfer of the encryption key from thePC30 to theprinter20 is enabled.
• [Modifications]
• While the present invention has been described with reference to the above particular illustrative embodiments, the present invention is not to be restricted by those embodiments but can also be implemented in various configurations.
• For example, while aprinter20 is employed in the above embodiments as the wireless station of the present invention, any type of device capable of operating as a wireless station can be employed as the wireless station of the present invention.
• While thePC30 is connected to theaccess point10 via thecable100 in the above embodiments, thePC30 may also be connected to theaccess point10 by wireless connection in cases where thePC30 has the wireless station function.
• While all the sequence containing the transmission of the probe reply is not executed by theprinter20 in the above embodiments when theprinter20 is judged not to be in the factory shipment state (see step S1410 inFIGS. 25, 27 and37), it is also possible to let theprinter20 transmit the probe reply in a state allowing the judgment on the factory shipment state and let theaccess point10 cancel the registration regarding the probe reply or the transmission of the request reminder data.
• For this, in theprinter20, the step S1410 is executed after the step S1440 as show inFIG. 42, for example. If “YES” in the step S1410, a probe reply, in which an “Unconfigured device” flag is set (set to “1”), is transmitted (S1412). If “NO” in the step S1410, an ordinary probe reply, in which the “Unconfigured device” flag is not set (set to “0”), is transmitted (S1450) and the process advances to the step S1460.
• Meanwhile, in theaccess point10, the following procedure is executed after the step S1160 or the step S1220 (S1222) ofFIGS. 23, 26,28,29,30,35 and36. For example, as shown inFIG. 43, after the step S1160, if the “Unconfigured device” flag in the received probe reply indicates that the wireless station (printer20) is in its factory shipment state (S1161: YES), the process advances to the step S1230 (S1162), otherwise (S1161: NO) the process advances to the step S1170. In the case where the judgment in the step S1220 (S1222) is “YES”, if the “Unconfigured device” flag in the received probe reply indicates that the wireless station is in its factory shipment state (S1224: YES), the process advances to the step S1240, otherwise (S1224: NO) the connection method instruction process is ended.
• By such a configuration, theaccess point10 is allowed to set the connection method (by carrying out the registration regarding the probe reply and the transmission of the request reminder data) only when the wireless station is in its factory shipment state.
Embodiment 12
• A wireless LAN system in accordance with a twelfth embodiment will be described hereinafter. It should be noted that a hardware configuration of the wireless LAN system according to the sixth embodiment is similar to that shown inFIG. 1 and the description there of is omitted for the brevity.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 44. The connection method instruction process is started when an instructing operation for switching the operation mode of theaccess point10 into a “support mode” (for supporting the setting of the connection method of the wireless station) is made by the user to the operation panel16 (e.g. pressing a particular button). Incidentally, the support mode is an operation mode which is enabled only in the connection method instruction process. When the connection method instruction process is ended, the operation mode of theaccess point10 is returned from the support mode to “normal mode”.
• First, a variable1M is initialized (S2110). In this step, a value “1” is set in the variable M (1→M). Incidentally, a character “m” in the following description system the value set in the variable M.
• Subsequently, a variable N is initialized (S2120). In this step, a value “1” is set in the variable N (1→N). A character “n” in the following description system the value set in the variable N.
• Subsequently, the method of wireless connection to the wireless station (hereinafter referred to as “connection method”) is switched to a connection method implemented by the n-th channel of the m-th wireless LAN standard (S2130). In this step, the connection method employed by thewireless LAN controller15 is switched by storing the parameters (for implementing a communication function by the connection method specified by the n-th channel of the m-th wireless LAN standard) in a storage area of theRAM13 for the parameters indicating the connection method” and letting thewireless LAN controller15 control the connection method according to the memory content of theRAM13. By this, the connection method will be controlled according to the memory content of theRAM13 until next switching (for controlling the connection method according to the memory content of the ROM12) is done in a posterior step (S2150). Incidentally, when the storage area for the “parameters indicating the connection method” already holds parameters, the parameters are overwritten with the new parameters.
• Subsequently, a probe request is broadcast (transmitted using a broadcast address as the destination) (S2140). The “probe request” is well-known frame data which is transmitted by the wireless access point for inquiring whether there exists a wireless station located nearby the wireless access point. In this embodiment, the probe request is transmitted for the purpose of supporting the setting of the connection method of wireless stations (see “REQUEST 11”-“REQUEST 3j” inFIG. 45). The probe request contains the SSID used by theaccess point10 for data communication with the wireless stations and the parameters indicating the connection method (the 2nd channel of the 1st wireless LAN standard) previously set to theaccess point10. From theprinter20 which received the probe request, a probe reply is returned according to the same connection method as that of theaccess point10 in the connection method setting process (FIG. 46) which will be explained later (see “REPLY” inFIG. 45).
• Subsequently, the connection method is returned to the initial settings (S2150). In this step, the “parameters indicating the connection method” stored in theRAM13 are deleted and thereafter data communication is carried out based on the “parameters indicating the connection method” stored in theROM12. The parameters stored in theROM12 are those that have been preset to theaccess point10 as the initial settings. Thus, the connection method of theaccess point10 is returned to the initial settings.
• Subsequently, a timer is started (S2160). The timer started in this step will be used for checking whether or not the probe reply is returned within a preset time limit from a wireless station (printer20) that should support the wireless connection setting.
• Subsequently, whether the probe reply has been returned from a wireless station or not is checked (S2170).
• If no probe reply has been returned (S2170: NO), whether or not a timeout has occurred since the transmission (broadcast) of the probe request is checked (S2180). In this step, the timeout is judged to have occurred if the timer which was started in the step S2160 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S2180: NO), the process returns to the step S170. If the timeout has occurred (S2180: YES), the timer started in the step S2160 is stopped and reset (S2190) and the variable N is incremented by 1 (n+1→N) (S2200).
• Subsequently, whether the transmission of the probe request has been finished by use of all the channels of the m-th wireless LAN standard or not is checked (S2210). Since the number of usable channels is specified and fixed in each wireless LAN standard, the transmission of the probe request by all the channels is judged to have finished in the step S210 if the value n of the variable N has become larger than the number (j) of usable channels of the m-th wireless LAN standard (n>j).
• If the transmission of the probe request by all the channels of the m-th wireless LAN standard has not been finished (S2210: NO), the process returns to the step S2130. Thereafter, the sequence from the step S130 to the step S2210 is repeated and thereby the transmission of the probe request is successively carried out by use of each channel of the m-th wireless LAN standard (see “REQUEST 11-“REQUEST 1j” inFIG. 45).
• After repeating the sequence from the step S2130 to the step S2210, if the transmission of the probe request by all the channels of the m-th wireless LAN standard has been finished (S2210: YES), the variable M is incremented by 1 (m+1→M) (S2220).
• Subsequently, whether the transmission of the probe request has been finished by use of all the wireless LAN standards or not is checked (S2230). In this step, the transmission of the probe request by all wireless LAN standards is judged to have finished if the value m of the variable N has become larger than the number (i) of wireless LAN standards that can be used by thewireless LAN controller15 for realizing communication (m>i).
• If the transmission of the probe request by all the wireless LAN standards has not been finished (S2230: NO), the process returns to the step S2120.
• Thereafter, the transmission of the probe request by use of the next wireless LAN standard is carried out by the sequence from the step S2120. By repeating the sequence from the step S120 to the step S2230, the transmission of the probe request is successively carried out by use of all the wireless LAN standards (see “REQUEST 11”-“REQUEST 3j” inFIG. 45).
• After repeating the sequence from the step S2120 to the step S2230, if the transmission of the probe request by all the wireless LAN standards has been finished (S2230: YES), the process returns to the step S2110.
• During the repetition of the sequence from the step S2120 to the step S2230, if the probe reply is returned from a wireless station (S2170: YES), the timer started in the step S2160 is stopped and reset (S2240) and a request reminder data is transmitted to the wireless station that returned the probe reply (S2250). The “request reminder data” is frame data which is used for reminding the wireless station (printer20) to send a request for permission for wireless connection (association request) to theaccess point10. Theprinter20 which received the request reminder data transmits the association request to theaccess point10 in the connection method setting process (FIG. 36) which will be explained later.
• Subsequently, another timer is started (S2260). The timer started in this step will be used for checking whether or not the association request is returned from the wireless station (printer20) within a preset time limit.
• Subsequently, whether the association request has been received from the wireless station or not is checked (S2270).
• If the association request has not been received (S2270: NO), whether or not a timeout has occurred since the transmission of the request reminder data is checked (S2280). In this step, the timeout is judged to have occurred if the timer started in the step S2260 has counted a preset length of time (250 msec in this embodiment).
• If the timeout has not occurred (S2280: NO), the process returns to the step S270. If the timeout has occurred (S2280: YES), the timer started in the step S2260 is stopped and reset (S2290) and the process returns to the step S2110.
• In the step S2270, if the association request has been received (S2270: YES), the timer is stopped and reset similarly to the step S2290 (S2300), and an association reply (permitting the wireless connection to the access point10) is transmitted to theprinter20 that returned the association request (S2310).
• As described above, the wireless connection between theaccess point10 and theprinter20 is established by the exchange of the association request and association reply.
• In this embodiment, although detailed explanation is omitted, before the exchange of the association request and association reply, an authentication request and an authentication reply are exchanged between theprinter20 and the access point10 (similarly to ordinary wireless connection procedures) after the request reminder data from theaccess point10 is received by the printer20 (see “AUTHENTICATION REQUEST”-“AUTHENTICATION REPLY” inFIG. 45). Incidentally, since the first embodiment does not employ encryption for data communication, the exchange of the authentication request/reply is done as open authentication (authentication without encryption).
• <Connection Method Setting Process byPrinter20>
• In the following, the connection method setting process which is conducted by;theCPU21 of theprinter20 will be described referring toFIG. 46. The connection method setting process is started when theprinter20 is activated.
• First, whether theprinter20 itself is in the factory shipment state or not is checked (S2410). In this step, theprinter20 is judged to be in its factory shipment state if no “parameters indicating the connection methods are stored in theROM22.
• If in the factory shipment state (S2410: YES), the initial settings are made (S2420). In this step, the initial settings are made by storing parameters that have been preset as the “parameters indicating the connection method” in theROM22. In this embodiment, parameters indicating a connection method specified by the 2nd channel of the 3rd wireless LAN standard are stored in theROM22 as the “parameters indicating the connection method”.
• Subsequently, a timer is started (S2430). The timer started in this step will be used for checking whether or not data is transmitted from a wireless access point (that should set the connection method) within a preset time limit. In this embodiment, the “wireless access point that should set the connection method” system theaccess point10, and the “data” means data that is transmitted by theaccess point10 in the aforementioned connection method instruction process (FIG. 44). Therefore, the user sets the connection method (for the connection to the access point10) to theprinter20 by activating the printer20 (i.e. starting this connection method setting process) after letting theaccess point10 start the aforementioned connection method instruction process (FIG. 44) (see “INSTRUCTING OPERATION” to theaccess point10 and “ACTIVATION” to theprinter20 inFIG. 45).
• Subsequently, whether a probe request has been received from a wireless access point or not is checked (S2440). The “probe request” is well-known frame data (MAC frame) which is transmitted by the wireless access point for inquiring whether there exists a wireless station located nearby the wireless access point, that is, data transmitted (broadcast) from theaccess point10 in the step S2140 ofFIG. 44. Specifically, in the step S2440, whether a probe request according to the connection method that has been set to theprinter20 itself (i.e. the connection method that has been set as the initial settings) has been received or not is checked (see “REQUEST 11-“REQUEST 3j” inFIG. 45).
• If a probe request has been received (S2440: YES), the connection method for the connection to the wireless access point is set based on the probe request (S2450). In this step, the connection method for the connection to the wireless access point is set by storing the “SSID” and the “parameters indicating the connection method” stored in the probe request in theROM22. By the above process, theprinter20 becomes capable of the wireless connection with theaccess point10 and the data communication using the SSID.
• Subsequently, a probe reply is returned according to the connection method set in the step S2450 (S2460). The probe reply is the data which is received by theaccess point10 in the step S2170 ofFIG. 44 (see “REPLY” inFIG. 45).
• After finishing the step S2460, or if no probe request has been received (S2440: NO), whether a request reminder data has been received from the wireless access point or not is checked (S2470). The request reminder data is the data which is transmitted by the access point10 (which received the probe reply transmitted in the step S2460) in the step S2250 ofFIG. 44.
• If no request reminder data has been received (S2470: NO), whether or not a timeout has occurred regarding the data reception from the wireless access point is checked (S2480). In this step, the timeout is judged to have occurred if the timer started in the step S2430 has counted a preset length of time (30 sec in this embodiment).
• If the timeout has not occurred (S2480: NO), the process returns to the step S2440.
• After repeating the sequence from the step S2440 to the step S2480, if the timeout has occurred (S2480: YES), the timer started in the step S2430 is stopped and reset (S2490), error notification is executed (S2500), and the connection method setting process is ended. In the step S2500, the user is notified of an error by an error message (indicating, for example, that there exists no wireless access point functioning normally around the printer20) displayed on the display panel49.
• During the repetition of the sequence from the step S2440 to the step S2480, if a request reminder data is received (S2470: YES), the timer started in the step S2430 is stopped and reset (S2510).
• After finishing the step S2510, or if theprinter20 is not in the factory shipment state in the aforementioned step S2410 (S2410: NO), an association request for requesting permission for wireless connection is transmitted to the access point10 (S2520). The “association request” is frame data (management frame) for requesting wireless connection permission (permission for wireless connection) from theaccess point10. In the step S2520, the SSID which was stored in theROM22 in the step S2450 is stored in the association request and transmitted (see “ASSOCIATION REQUEST” inFIG. 45). Incidentally, in the header (header information) of the association request, the device ID of the printer20 (MAC address) is set (stored). From theaccess point10 which received the association request, an association reply, as frame data (management frame) indicating the permission for the wireless connection to theaccess point10, is returned (see “ASSOCIATION REPLY” inFIG. 45).
• Subsequently, another timer is started (S2530). The timer started in this step will be used for checking whether or not the association reply is returned within a preset time limit.
• Subsequently, whether or not a timeout has occurred since the transmission of the association request is checked (S2540). In this step, the timeout is judged to have occurred if the timer started in the step S2530 has counted a preset length of time (250 msec in this embodiment).
• It the timeout has not occurred (S2540: NO), whether the association reply has been received from theaccess point10 or not is checked (S2550). If the association reply has not been received (S2550: NO), the process returns to the step S2540.
• Thereafter, the steps S2540 and S2550 are repeated and if the timeout (since the transmission of the association request) has occurred (S2540: YES), the timer started in the step S2530 is stopped and reset (S2570), and the process returns to the step S2420.
• On the other hand, if the association reply has been received in the step S2550 (S2550: YES), the timer started in the step S2530 is stopped and reset (S2580), and the connection method setting process is ended.
• In the wireless LAN system composed as above, theaccess point10 transmits the probe request to the wireless stations (including the printer20) according to each of a plurality of connection methods (see “REQUEST” inFIG. 45). The probe request is received by theprinter20 to which the same connection method has been set (see “REQUEST 32” inFIG. 45), and theprinter20 sets the connection method specified by the probe request (which is the same as the connection method which has been set to the access point10) to itself. By setting theprinter20 to the same connection method as theaccess point10 as above, wireless connection between theaccess point10 and theprinter20 becomes possible.
• As above, in theprinter20, the connection method for the connection to theaccess point10 is set automatically via the reception of the probe request (S2440-S2460 inFIG. 46). Therefore, the load on the user regarding the wireless LAN settings can be lightened remarkably.
• After the connection method has been set to theprinter20, the wireless connection between theaccess point10 and theprinter20 can be established immediately via the exchange of the association request/reply.
• Theaccess point10 transmits the probe requests while successively switching the connection method in turn at prescribed time intervals (S2110-S2230 inFIG. 44), and if a probe reply is received in a period before the switching to the next connection method (S2170), transmits the request reminder data according to the connection method at the point of the reception of the probe reply (S2250).
• As above, theaccess point10 can set the connection method (which has been preset to theaccess point10 itself) to theprinter20 only by transmitting the probe requests according to each connection method while successively switching the connection method in turn.
• Theaccess point10 is capable of transmitting the probe request according to each connection method by switching and changing the connection method temporarily (S2110-S2230 inFIG. 44). The period of time in which the connection method is changed (S2130-S2150 inFIG. 44) is limited to the period of transmission of the probe request, and the reply is made by the connection method previously set to theaccess point10. During the period in which the connection method is changed from the preset connection method (S2130), theaccess point10 generally can not carry out data communication which should be conducted according to the preset connection method. Therefore, the shortness of the period (in which the connection method is changed) is advantageous for avoiding the inconvenience of the interruption of data communication which should be conducted according to the preset connection method.
• The starting of the connection method instruction process (FIG. 44) by theaccess point10 can be ordered explicitly from outside by the instructing operation. similarly, starting of the connection method setting process (FIG. 46) by theprinter20 can be ordered explicitly from outside by activating theprinter20.
• The setting of the connection method to theprinter20 can be executed only when theprinter20 is in its factory shipment state (S2410 ofFIG. 46).
Modification ofEmbodiment 12
• The twelfth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while the process from the step S2420 is executed only when theprinter20 is in its factory shipment state (S2410 ofFIG. 46) in the above embodiment, it is also possible to configure theprinter20 to execute the process from the step S2420 even if it is not in the factory shipment state, in cases where the setting of the connection method is necessary (e.g. when part of the “parameters indicating the connection method” stored in theROM22 is lacking). While the step S2410 judges that theprinter20 is in the factory shipment state if no “parameters indicating the connection method” are stored in theROM22, it is also possible to set a specific flag at the stage of factory shipment and use the flag for indicating the factory shipment state. In this case, theprinter20 is judged to be in the factory shipment state if the flag is still set. The flag is reset when the “parameters indicating the connection method” are stored in theROM22.
• While the association request and association reply are exchanged after the exchange of the authentication request and authentication reply in the above embodiment, it is also possible to omit the authentication request/reply and carry out the exchange of the association request/reply only.
• While the setting of the connection method to theprinter20 is ordered and started by the activation of theprinter20 in the above embodiment, the order can also be issued by, for example, a particular operation through the operation panel26 (see “ORDER” inFIG. 45).
• While the operation mode of theaccess point10 is switched by the instructing operation in the above embodiment, theaccess point10 may also be configured to switch its operation mode when instructed by data which is sent from another device capable of communicating with theprinter20.
• While theprinter20 in the above embodiment checks whether its in the factory shipment state or not (S2410 inFIG. 46) just after starting the connection method setting process and then executes the process from the step S2420, the timing of the check on the factory shipment state is not limited to the point just after the start of the connection method setting process. Before the step S2440, before the step S2510, etc. are also possible.
• While theaccess point10 in the above embodiment transmits a probe request as data for supporting the setting of the connection method of the wireless stations, data other than the probe request can also be employed as long as the same purpose can be achieved.
• While theaccess point10 in the above embodiment switches its connection method in numerical order starting from the 1st channel of the1st wireless LAN standard, the order of the channel switching is not particularly limited. For example, a proper order for avoiding radio wave interference in the same wireless LAN standard may also be employed.
• It is also possible to let theaccess point10 first conduct the process from the step S140 with the connection method preset to itself and then repeat the same process by use of each connection method in numerical order starting from the 1st channel of the 1st wireless LAN standard.FIG. 47 shows an example of such a process flow, in which steps S2101-S2105 equivalent to the steps S2140, S2160-S2190 ofFIG. 44 are added before the step S2110 ofFIG. 44. If a probe reply to the probe request transmitted according to the preset connection method is received (S2103: YES), the process advances to the step S2240. On the other hand, if a timeout occurs without receiving the probe reply (82104: YES), the timer is stopped and reset (S2105) and the process advances to the step S2110. Preferably, a judgment step may also be provided between the steps S2190 and S2200, by which the process advances to the step S2200 only when the connection method after incrementing the variable N by 1 is not identical with the initial settings, and otherwise (when the connection method after the increment is identical with the initial settings) the process returns to the step82190.
• By such composition, the wireless connection between theaccess point10 and theprinter20 can be established immediately in cases where theprinter20 has the initial settings identical with the connection method preset to theaccess point10.
• While theaccess point10 returns to the step S2110 when the judgment in the step S2230 ofFIG. 44 is “YES” in the above embodiment, theaccess point10 may also end the connection method instruction process (FIG. 44) when the judgment is “YES”, as shown inFIG. 47. In this case, theaccess point10 is allowed to end the connection method instruction process after transmitting the probe requests by use of all the connection methods since the start of the connection method instruction process.
Embodiment 13
• A wireless LAN system in accordance with a second embodiment of the present invention is composed similarly to the system of the first embodiment except for some steps executed by theprinter20, therefore, only the point of difference will be explained below.
• <Connection Method Setting Process byPrinter20>
• In the following, the connection method setting process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 48. The connection method setting process ofFIG. 48 is configured by replacing the steps S2440-S2500 of the connection method setting process in the first embodiment (FIG. 46) with the following procedure, therefore, only the procedure different from the twelfth embodiment will be described in detail. In the following explanation, steps identical with those of the twelfth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• If a probe request has been received from theaccess point10 in the step S2440 (S2440: YES), whether the probe request has already been registered or not is checked (S2441). In this connection method setting process, parameters specified by the probe request are registered in a posterior step. Therefore, in the step S2441, the received probe request is judged to have already been registered if the parameters specified by the probe request have already been registered.
• If the probe request has not been registered yet (S2441: NO), the parameters specified by the probe request are registered, by storing the parameters in a parameter storage area of the RAM23 (S2442). In this embodiment, theaccess point10 is configured to transmit a probe request containing not only the SSID and the connection method but also parameters such as the device ID of theaccess point10 in the step S2140 ofFIG. 44. In the step S2442, the parameters are registered together with a value indicating the reception level (radio field intensity) when the probe request was received, associating them with one another. Data table with which the parameters specified by the probe request are registered is similar to that employed in the first embodiment and shown inFIG. 5.
• After finishing the step S2442, or if the probe request has already been registered in the step S2441 (S2441: YES), whether or not a timeout has occurred regarding the reception of the probe request from the wireless access point is checked (82443). In this step, the timeout is judged to have occurred if the timer started in the step S2430 has counted a preset length of time (30 sec in this embodiment).
• If the timeout has not occurred (S2443: NO), the process returns to the step S2440. If the timeout has occurred (S2443: YES), the timer which was started in the step S2430 is stopped and reset (S2444).
• Subsequently, whether or not the registration of parameters has been carried out in the step S2442 is checked (S2445). In this step, the registration of parameters in the step S2442 is judged to have been carried out if data (data table) indicating the parameters have been stored in the parameter storage area of theRAN23.
• If the parameter registration has not been carried out (S2445: NO), the process advances to the step S2500, otherwise (S2445: YES) the process advances to step S2450.
• In the step32450, from the “parameters indicating the connection method” registered in the step S2442, a set of “parameters indicating the connection method” corresponding to the highest reception level is selected and stored in theROM22, by which the connection method is set.
• After finishing the steps S2450 and S2460, a timer is started similarly to the step S2430 (S2462) and the process advances to the step S2470. In the step S2470, if the request reminder data has not been received (S2470: NO), the process advances to step S2480. In the step S2480, the process returns not to the step S2440 but to the step S2470 if a timeout has not occurred (S2480: NO).
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the twelfth embodiment.
• Theprinter20 is capable of selecting a connection method that is specified by the probe request having the highest reception level out of the probe requests collected (registered) in a preset time period (S2442 inFIG. 48) and set the selected connection method to itself as the connection method for the connection to the wireless access point (S2450 inFIG. 48).
• Such setting of the connection method (for the connection to the wireless access point) specified by the probe request having the highest reception level is advantageous for preventing erroneous setting of the connection method of theprinter20 to a false connection method different from the method for the connection to the correct wireless access point.
• If another wireless access point similar to the access point10 (wireless access point) of the present invention also exists in the vicinity of the printer20 (e.g. in an adjacent residence) when the connection method (for the connection to the wireless access point) is set to the printer20 a probe request is sent also from the (other) wireless access point and thus there is a possibility that a connection method identical with the method set to the (other) wireless access point might be set to theprinter20 regardless of the user's intention, depending on the timing of the reception of probe request.
• However, since the thirteenth embodiment enables the setting of the connection method (for the connection to the wireless access point) that is specified by the probe request having the highest reception level as above, the erroneous connection method setting based on the probe request from other wireless access points can be avoided only by putting theprinter20 and theaccess point10 sufficiently in the vicinity of each other for gaining enough reception level during the radio communication.
Embodiment 14
• A wireless LAN system in accordance with a fourteenth embodiment of the present invention is composed similarly to the system of the twelfth embodiment except for some steps executed by theaccess point10, therefore, only the point of difference will be explained below.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 49. The connection method instruction process is configured by replacing the step S2240 of the connection method instruction process of the twelfth embodiment (FIG. 48) with a step S2172 which will be explained below and adding a step S2232 (explained below) after the step S230, therefore, only the procedure different from the twelfth embodiment will be described in detail. In the following explanation, steps identical with those of the twelfth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• If a probe reply has been received in the step S2170 (S2170: YES), parameters specified by the probe reply are registered by storing them in a parameter storage area of the RAM13 (S2172). In this embodiment, theprinter20 returns the probe reply which contains the SSID and the device ID in the step S2460 ofFIG. 46. In the step S2172, the SSID and the device ID are registered together with parameters indicating the connection method and the reception level at the point when the probe reply was received in the step S2170, associating them with one another.
• After finishing the step S172, the process advances to the step S2180, similarly to the case of “NO” in the step S2170.
• After the steps S2180-S2230, if the judgment in the step S230 is “YES”, whether or not the registration of parameters has been carried out in the step S2172 is checked (S2232). In this step, the registration of parameters in the step S2172 is judged to have been carried out if data indicating the parameters have been stored in the parameter storage area of theRAM13.
• If the parameter registration has been carried out in the step S2232 (82232: YES), the process returns not to the step S2110 but to step S2250. In the step S2250, the request reminder data is transmitted to a single wireless station only, according to the SSID and the connection method corresponding to (associated with) the highest reception level that are selected from the parameters registered in the step S2172.
• on the other hand, if the parameter registration has not been carried out in the step S2232 (S2232: NO), the connection method instruction process is ended.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the twelfth embodiment.
• Theaccess point10 is capable of setting the connection method to the wireless station returning the probe reply of the highest reception level by transmitting the request reminder data to the wireless station.
• Therefore, erroneous transmission of the request reminder data to a different wireless station (different from the wireless station (printer20) to which the connection method should be set) and the setting of the connection method to the different wireless station can be avoided only by putting theaccess point10 and theprinter20 sufficiently in the vicinity of each other for gaining enough reception level during the radio communication similarly to the thirteenth embodiment.
Modification ofEmbodiment 14
• The fourteenth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• While theaccess point10 transmits the request reminder data to the wireless station returning the probe reply of the highest reception level in the step S2250 ofFIG. 49, theaccess point10 may also be configured to transmit the request reminder data to any wireless stations returning the probe reply of a reception level higher than a threshold level in the step S2250.
Embodiment 15
• A wireless LAN system in accordance with a fifteenth embodiment of the present invention is composed similarly to the system of the twelfth embodiment except for some steps executed by theaccess point10, therefore, only the point of difference will be explained below.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 50. The connection method instruction process is configured by adding steps S2234 and S2236 (explained below) after the step S2232 of the connection method instruction process of the fourteenth embodiment (FIG. 49), therefore, only the procedure different from the twelfth embodiment will be described in detail. In the following explanation, steps identical with those of the fourteenth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• In this embodiment, theprinter20 returns the probe reply which contains the SSID, a device name and the device ID in the step S2460 ofFIG. 46. In the step S2172 of the connection method instruction process of this embodiment, the SSID, the device name and the device ID are registered together with parameters indicating the connection method and the reception level at the point when the probe reply was received in the step S2170, associating them with one another.
• Afterward, if the parameter registration has been carried out in the step S2232 (S2232: YES), a device name list containing the parameters registered in the step S2172 is displayed on thedisplay panel17 in order to inform the user of the device names. After the list is displayed on thedisplay panel17, the user can make a selection of a device name from the device names on the list (selection operation) through theoperation panel16.
• The selection operation is waited for until it is made by the user (S2236: NO).
• When the selection operation is made (S2236: YES), the process advances to the step S250. Incidentally, to the parameter corresponding to the device name selected by the selection operation, a selection flag indicating the selection by the selection operation is set (initial value “On is turned into “I”).
• In the step S250, the request reminder data is transmitted to the selected wireless station, according to the parameters (SSID and connection method) to which the selection flag has been set (i.e. parameters selected from the parameters registered in the step S2172).
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the first embodiment.
• Theaccess point10 is capable of setting the connection method only to the wireless station having the device name that is arbitrarily selected by the user (e.g. printer20) by transmitting the request reminder data to the wireless station (steps S2234, S2236 and S2250 inFIG. 50).
Modification ofEmbodiment 15
• The fifteenth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• While the selection operation by the user in the steps S2234 and S2236 ofFIG. 50 is carried out based on the device names, the selection operation may also be carried out based on the device IDs instead of the device names. In this case, the connection method can be set to the wireless station having the device ID arbitrarily selected by the user by transmitting the request reminder data to the wireless station only.
Embodiment 16
• A wireless LAN system in accordance with a sixteenth embodiment of the present invention is composed similarly to the system of the sixteenth embodiment. The sixteenth embodiment is configured so that the notification of device names and the selection operation (carried out by theaccess point10 in the fifteenth embodiment) can be executed by a commonly used computer system30 (hereinafter referred to as a “PC30”) which is connected to theaccess point10 to communicate data via a cable100 (seeFIG. 1).
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 51. The connection method instruction process is configured by replacing the steps S234 and S2236 of the connection method instruction process of the fifteenth embodiment (FIG. 50) with steps S2238 and S2239 which will be explained below, therefore, only the procedure different from the fourth embodiment will be described in detail. The connection method instruction process is started after start instruction data is received from the PC30 (see “START INSTRUCTION” inFIG. 52).
• If the parameter configuration has been carried out in the step S2232 (S2232: YES), listing data, representing the list of the device names specified by the registered parameters, is generated and transmitted to the PC30 (the device which transmitted the start instruction data) (S2238). ThePC30 which received the listing data (see “LISTING DATA” inFIG. 52) displays the list represented by the listing data on its display, by which the user is informed of the device names. Thereafter, when the selection operation (for selecting a device name from the device names on the list) is made by the user, selection data which can specify the selected device name is generated and transmitted to the access point10 (see “SELECTION DATA” inFIG. 52).
• After the transmission of the listing data in the step S2238, reception of the selection data is waited for (S2239: NO). When the selection data is received (S2239: YES), the process advances to step S2250.
• In the step S2250, the request reminder data is transmitted to the selected wireless station according to the parameters (SSID and connection method) corresponding to (associated with) the device name specified by the selection data received in the step S2239.
• <Setting Instruction Process byPC30>
• In the following, a setting instruction process which is conducted by thePC30 will be described referring toFIG. 53. The setting instruction process is executed according to a program installed in thePC30.
• First, the start instruction data is transmitted to the access point10 (S2610). Theaccess point10 which received the start instruction data starts the aforementioned connection method instruction process ofFIG. 51 (see “START INSTRUCTION” inFIG. 52) and transmits the aforementioned listing data after a while.
• The listing data from theaccess point10 is waited for until it is received (S2620: NO).
• When the listing data is received (S2620: YES), the content of the listing data is displayed on the display of the PC30 (S2630). After the list of device names represented by the listing data is displayed (seeFIG. 54), the user can make the selection operation (for selecting a device name) by use of a keyboard, mouse, etc.
• The selection operation is waited for until it is made by the user (S2640: NO) When the selection operation is made (92640: YES), the selection data which can specify the device name selected by the selection operation is generated and transmitted to the access point10 (S2650). Theaccess point10 which received the selection data (see “SELECTION DATA” inFIG. 52) transmits the request reminder data to the wireless station having the device name specified by the selection data (see “REQUEST REMINDERS inFIG. 52).
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the fifteenth embodiment.
• Theaccess point10 is capable of setting the connection method only to the wireless station (e.g. printer20) having the device name that is specified by the selection data received from the PC30 (i.e. the device name that is arbitrarily selected by the user from the device names which have been registered based on the probe replies) by transmitting the request reminder data to the wireless station.
Modification ofEmbodiment 16
• The sixteenth embodiment can also be implemented with part of its composition altered to other composition as shown below. Incidentally, the composition shown below is also applicable to similar parts of other embodiments.
• For example, while theaccess point10 generates the listing data which represents the list of device names in the step S238 ofFIG. 51, theaccess point10 may also be configured to generate and transmit listing data that represents a list of device IDs, let the user of thePC30 carry out the selection operation based on the device IDs instead of the device names, and transmit the request reminder data to the selected wireless station according to the parameters (SSID and connection method) corresponding to (associated with) the selected device ID in the step S2250. In this case, the connection method can be set only to the wireless station having the device ID arbitrarily selected by the user of thePC30 by transmitting the request reminder data to the wireless station.
• While theaccess point10 registers (collects) the parameters for a prescribed time period and thereafter transmits the listing data generated based on the collected parameters in the above embodiment, theaccess point10 may also be configured to generate and the transmit the listing data at the point when a request for transmission is received from the PC30 (see “LISTING REQUEST” inFIG. 52). For this configuration, a step for waiting for an operation requesting the listing data (step S2612) is added between the steps S2610 and S2620 ofFIG. 53 and a step for requesting (the transmission of) the listing data in response to the above operation (step S2614) is added after the step S2612 as shown inFIG. 55, and a step for waiting for the request from the PC30 (step S233) is added between the steps S2232 and S2238 ofFIG. 51 as shown inFIG. 56, for example. Also in this configuration, the selection operation may also be carried out based on the device IDs instead of the device names, similarly to the configuration mentioned above.
• It is also possible in the above embodiment to configure theaccess point10 to notify thePC30 that the connection method has been set (or will be set) to the wireless station after theaccess point10 has transmitted the request reminder data to the wireless station (printer20). For this configuration, a step for transmitting setting notification data (for the notification of the execution of the setting) to the PC30 (S2312) is added after the step S2310 ofFIG. 51 as shown inFIG. 56, and a step for waiting for the setting notification data (S2652) and a step for notifying the user that the connection method has been set to the wireless station in response to the reception of the setting notification data (S2654) are added after the step S2650 ofFIG. 53 as shown inFIG. 55, for example.
Embodiment 17
• In some embodiments described above, even if theprinter20 is connected to theaccess point10 by wireless connection, if theaccess point10 is configured to carry out data communication employing encryption, normal data communication is generally impossible without similarly configuring theprinter20 to execute the data communication employing the encryption. Therefore, the wireless LAN system of this embodiment is designed for letting the wireless LAN system of the above sixteenth embodiment carry out data communication normally without the need of operations by the user.
• First, if a “parameter regarding security” is stored in theROM12, theaccess point10 starts executing communication with security measures based on the parameter. As the “parameter regarding security”, an encryption key for carrying out the communication in an encrypted state (e.g. WEP (Wired Equivalent Privacy) key in this embodiment) can be employed for example. If an encryption key has been stored in theROM12, the access point10 (CPU11) carries out the communication with the wireless station by encrypting data with the encryption key. Incidentally, the encryption key is generated and stored in theROM12 by the aforementioned remote setup.
• Meanwhile, if a “parameter regarding security” is stored in theROM22, theprinter20 starts executing communication with security measures based on the parameter. As the “parameter regarding security”, an encryption key can be employed similarly to the case of theaccess point10. If an encryption key has been stored in theROM22, the printer20 (CPU21) carries out the communication with the wireless access point by encrypting data with the encryption key.
• <Connection Method Instruction Process byAccess Point10>
• In the following, a connection method instruction process which is conducted by theCPU11 of theaccess point10 will be described referring toFIG. 57. The connection method instruction process is configured by adding steps S2314, S2316 and S2318 (explained below) after the step S2310 of the connection method instruction process of the sixteenth embodiment (FIG. 51), therefore, only the procedure different from the sixteenth embodiment will be described in detail.
• In the step S2250 in this embodiment, an encryption key that is different from the ordinary encryption key stored in the ROM12 (hereinafter referred to as a “tentative encryption key”) is generated randomly, and a request reminder data to which the tentative encryption key is attached is transmitted to the wireless station without encrypting the data with the encryption key.
• After finishing the sequence to the step S2310 after transmitting the request reminder data in the step S2250, the device name and the device ID of the wireless station (to which the request reminder data was transmitted in the step S2250) are registered with a reminder list associating them with the tentative encryption key attached to the request reminder data in the step S2250 (S2314). The “reminder list” is a data table which is generated in theRAM13 for the registration of the data.
• The release of the wireless connection with the wireless station registered with the reminder list in the step S2314 is waited for (S2316: NO). When the wireless connection is released (S2316: YES), the information registered with the reminder list is deleted (S2318) and the connection method instruction process is ended.
• <Connection Method Settling Process byPrinter20>
• In the following, a “connection method settling process” which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 58. The connection method settling process is a process configured by adding a step S2472 (explained below) after the step S2470 of the connection method setting process of the sixteenth embodiment (FIG. 47) and adding a sequence explained below after the step S2580. In the following explanation, steps identical with those of the sixteenth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• First, the tentative encryption key attached to the request reminder data received in the step S2470 is set (S2472). In this step, the tentative encryption key is stored in a storage area of theRAM23 for the “parameter regarding security”, by which subsequent data communication with the wireless access point (access point10) will be carried out by encrypting data with the tentative encryption key.
• After finishing the step S2580, the encryption key of theaccess point10 is acquired (S2700). The step S2700 is a step for acquiring the encryption key of theaccess point10 from thePC30 by means of the public key cryptosystem (see “ENCRYPTION KEY (ENCRYPTED BY RANDOM NUMBER)” inFIG. 59). Details of the step S700 will be explained later in an explanation of an encryption key acquisition process (FIG. 60).
• If the encryption key is acquired successfully in the step S2700 (S2582: YES), the encryption key is stored in the RON22 (S2584). In this step, in addition to the storage of the encryption key in theROM22, deletion of the tentative encryption key from theRAM23 is executed.
• Subsequently, the wireless connection with theaccess point10 is released (S2586). In this step, the wireless connection with theaccess point10 is released by transmitting an authentication release message to the access point10 (see “AUTHENTICATION RELEASE” inFIG. 59).
• Subsequently, the wireless connection with theaccess point10 is reestablished (S2588). In this step, the wireless connection is reestablished by exchanging the authentication request/reply with theaccess point10 similarly to the aforementioned procedure. Incidentally, the exchange of the authentication request/reply in this step is carried out by means of shared key authentication (based on encryption) using the encryption key transferred to theprinter20. After the wireless connection is established by this step, data communication is executed by encrypting data with the encryption key rewritten in the step S2584.
• After the step S2588, or if the encryption key has not been acquired in the step S2582 (S2582: NO), the connection method settling process is ended.
• <Encryption Key Acquisition Process byPrinter20>
• In the following, an encryption key acquisition process which is conducted by theCPU21 of theprinter20 will be described referring toFIG. 60. The encryption key acquisition process is the details of the step S2700 ofFIG. 58.
• First, a public key and a private key used for the public key cryptosystem as a pair are generated (S2710).
• Subsequently, the public key generated in the step S2710 is transmitted to the PC30 (S2720). In this step, data of the public key is transmitted to thePC30 as a prescribed device. ThePC30 which received the public key encrypts a random number (which is generated randomly) by the public key and transmits the encrypted random number to theprinter20. ThePC30 further transmits prescribed print data (representing a prescribed message image) encrypted by the random number to the printer20 (see “RANDOM NUMBER (ENCRYPTED BY PUBLIC KEY)” and “PRINT DATA (ENCRYPTED BY RANDOM NUMBER)” inFIG. 59).
• Theprinter20 receives the encrypted random number from the PC30 (S2730), receives the encrypted print data from the PC30 (S2740), decrypts the message image (represented by the print data received in the step S2740) by the public key generated in the step S2710, and lets theprint engine28 print the message image (S2750). The message image printed in this step contains a message for letting the user confirm that the random number received in the step S2730 was transmitted by thePC30 certainly to theprinter20 itself. The user who confirmed the fact conducts a confirmation operation (which will be described later in an explanation of a setting instruction process (FIG. 62)) by use of thePC30. After the confirmation operation, the encryption key encrypted in the step S2770 will be transmitted from thePC30 to theprinter20.
• A timer is started (S2760) and whether the encryption key has been received or not is checked (S2770). If the encryption key has been received (S2770: YES), the timer which was started in the step S760 is stopped and reset (S2780) and the encryption key acquisition process is ended.
• On the other hand, if the encryption key has not been received (S2770: NO), whether a timeout has occurred or not is checked (S790). In this step, the timeout is judged to have occurred if the timer started in the step S760 has counted a preset length of time (30 sec in this embodiment).
• If the timeout has not occurred (S2790: NO), the process returns to the step S770. If the timeout has occurred (S2790: YES), the process advances to the step S2780 by which the encryption key acquisition process is ended without acquiring the encryption key.
• <Setting Instruction Process byPC30>
• In the following, a setting instruction process which is conducted by thePC30 will be described referring toFIG. 61. The setting instruction process is executed according to a program installed in thePC30. The setting instruction process is configured by adding the following procedure after the step S2650 of the setting instruction process of the fifth embodiment (FIG. 53). In the following explanation, steps identical with those of the fifth embodiment will be referred to with the same step Nos. and detailed explanation thereof is omitted for brevity.
• After the step S650 is finished, the public key transmitted from theprinter20 is waited for until it is received (S2810: NO). The public key is the data which is transmitted by theprinter20 in the step S2720 ofFIG. 60.
• When the public key is received (S2810: YES), a random number (generated randomly) is encrypted by the public key and the encrypted random number is transmitted to theprinter20. The encrypted random number is the data which is received by theprinter20 in the step S2730 ofFIG. 60.
• Subsequently, the print data representing the message image is encrypted by random number received in the step82810 and the encrypted print data is transmitted to the printer20 (S2830). The encrypted print data is the data which is received by theprinter20 in the step S2740 ofFIG. 60. Theprinter20 which received the print data prints the message image, and the user conducts the confirmation operation to thePC30 after the message image is printed out, as mentioned above. The confirmation operation is done by pressing a particular key/button, pressing keys/buttons in a particular order, etc.
• The confirmation operation is waited for until it is done by the user (82840: NO).
• When the confirmation operation is conducted (S2840: YES), the encryption key is encrypted by the random number generated in the step S2820 and the encrypted encryption key is transmitted to the printer20 (S2850). The encrypted encryption key is the data which is received by theprinter20 in the step S2770 ofFIG. 60. Incidentally, the encryption key is data which has previously been stored in memory, etc.
• After finishing the step S850, the setting instruction process is ended.
• <Encryption Switching Process byAccess Point10>
• Theaccess point10 is configured to execute an encryption switching process when the time of data communication (transmission/reception of data) with a wireless station has come since its activation. In the following, the encryption switching process will be described referring toFIG. 62.
• First, whether the wireless station (to carry out data communication with) is a wireless station having a device name or device ID registered with the reminder list of theRAM13 or not is checked (S2910).
• If the wireless station is one having a device name or device ID registered with the reminder list (S2910: YES), data communication is carried out by encrypting data with a tentative encryption key corresponding to the device name or device ID (S2920).
• On the other hand, if the wireless station is one having no device name nor device ID registered with the reminder list (S2910: NO), ordinary data communication is carried out by encrypting data with the encryption key (S2930).
• finishing the steps S2920 or S2930 as above, the encryption switching process is ended.
• In the wireless LAN system composed as above, the following effects can be achieved in addition to the effects attained by the previous embodiments.
• For a wireless station to which the request reminder data has been transmitted, theaccess point10 switches its encryption method so as to execute data communication encrypting data with the tentative encryption key (S2910 inFIG. 62). Meanwhile, theprinter20 which received the request reminder data sets its encryption method so as to execute the data communication with theaccess point10 encrypting data with the tentative encryption key (S2472 inFIG. 58). By the procedure, normal data communication between theaccess point10 and theprinter20 encrypting data with the tentative encryption key becomes possible, by which the data communication between theaccess point10 and theprinter20 can be realized ensuring a certain security level while maintaining the security level of data communication of theaccess point10 with external networks.
• Subsequently, if theprinter20 successfully acquires the encryption key by the encryption key acquisition process (FIG. 60), theprinter20 reestablishes the wireless connection with the access point10 (see steps S2586 and S588 inFIG. 58), by which the data communication between theaccess point10 and theprinter20 will thereafter be carried out by encrypting data with the encryption key transferred from thePC30 to theprinter20. In theaccess point10, the information registered with the reminder list is deleted at this point (see step S2318 inFIG. 57), by which the encryption method of theaccess point10 is returned so as to execute the data communication with theprinter20 encrypting data with the encryption key. Therefore, the data communication between theaccess point10 and theprinter20 can be realized with a security level equivalent to that of data communication of theaccess point10 with other wireless stations or external networks.
• Since the transfer of the encryption key from thePC30 to theprinter20 is conducted by means of the public key cryptosystem, the probability of leak of the encryption key during the transmission to theprinter20 becomes low as a matter of course.
• Further, theprinter20 prints the message image represented by the print data transferred from thePC30 prior to the encryption key (see step S2750 inFIG. 60). Thus, the user is allowed to confirm whether or not theprinter20 is a correct wireless station that should receive the encryption key from thePC30, by checking whether or not the message image is printed by theprinter20. After confirming the message image, the user executes the confirmation operation to the PC30 (see step S2840 inFIG. 61), by which the transfer of the encryption key from thePC30 to theprinter20 is enabled.
• [Modifications]
• While the present invention has been described with reference to the above particular illustrative embodiments, the present invention is not to be restricted by those embodiments but can also be implemented in various configurations.
• For example, while aprinter20 is employed in the above embodiments as the wireless station of the present invention, any type of device capable of operating as a wireless station can be employed as the wireless station of the present invention.
• While thePC30 is connected to theaccess point10 via thecable100 in the above embodiments, thePC30 may also be connected to theaccess point10 by wireless connection in cases where thePC30 has the wireless station function.
• While all the sequence containing the transmission of the probe reply is not executed by theprinter20 in the above embodiments when theprinter20 is judged not to be in the factory shipment state (see step S2410 inFIGS. 46, 48 and58), it is also possible to let theprinter20 transmit the probe reply in a state allowing the judgment on the factory shipment state and let theaccess point10 cancel the registration regarding the probe reply or the transmission of the request reminder data.
• For this, in theprinter20, the step S2410 is executed after the step S2450 as show inFIG. 63, for example. If “YES” in the step S2410, a probe reply, in which an “Unconfigured device” flag is set (set to “1”), is transmitted (S2412). If “NO” in the step S410, an ordinary probe reply, in which the “Unconfigured device” flag is not set (set to “0”), is transmitted (S2414) and the process advances to the step S2470.
• Meanwhile, in theaccess point10, the following procedure is executed after the step S2170 or the step S2230 (S2232) ofFIGS. 44, 47,49,50,51,56 and57. For example, as shown inFIG. 54, after the step S2170, if the “Unconfigured device” flag in the received probe reply indicates that the wireless station (printer20) is in its factory shipment state (S2171: YES), the process advances to the step S2240 (S2172), otherwise (S2171: NO) the process advances to the step S2180. In the case where the judgment in the step S2230 (S2232) is “YES”, if the “Unconfigured device” flag in the received probe reply indicates that the wireless station is in its factory shipment state (S22,34: YES), the process advances to the step S2250, otherwise (S2234: NO) the connection method instruction process is ended.
• By such a configuration, theaccess point10 is allowed to set the connection method (by carrying out the registration regarding the probe reply and the transmission of the request reminder data) only when the wireless station is in its factory shipment state.
• While theprinter20 which received the probe request is thereafter kept in the same connection method (specified by the probe request) after the transmission of the probe reply in the above embodiments, theprinter20 may also be configured to once return the connection method to the initial settings after the transmission of the probe reply and set the connection method again after receiving the request reminder data. Such a configuration is desirable for preventing theprinter20 from erroneously switching its connection method according to a probe request transmitted by a different wireless access point. For this purpose, the following specific configuration can be employed, for example.
• As shown inFIG. 65, in theprinter20, a step for returning its connection method to the initial settings (step S2464) is added between the step S2460 and the next step in the connection method setting process (FIGS. 48, 58 and63), and a step for setting its connection method (step S2512 (similar to the step S2450)) is added between the step S2510 and the next step. In the step S2460, the probe reply is transmitted in a state capable of specifying the connection method preset to theprinter20. In this configuration, theprinter20 executes the transmission of the probe reply according to the connection method of theaccess point10 and thereafter executes the reception of the request reminder data according to the connection method preset to theprinter20 itself. As shown inFIG. 66, in theaccess point10, a step for switching its connection method to the method specified by the probe reply received in the step S2170 (step S2242) is added between the step S2250 and the immediately precedent step in the connection method instruction process (FIGS.46,49-51,56,57 and64), and a step for returning its connection method to the method based on the n-th channel of the m-th wireless LAN standard (step S2252) is added between the step S2250 and the next step. In this configuration, theaccess point10 executes the reception of the probe reply according to the connection method preset to theaccess point10 itself and thereafter executes the transmission of the request reminder data according to the connection method of theprinter20.
• In the above-described embodiments, theprinter20 is used as the wireless station. However, the invention need not be limited in this configuration and various other devices such as scanner, facsimile, copier, camera device, audio-visual device, household electric appliance and storage device may be optionally or alternatively employed as the wireless station.
• The present disclosure relates to the subject matters contained in Japanese Patent Applications No. 2003-362230, No. 2003-362231 and No. 2003-362232, all filed on Oct. 22, 2004, which are expressly incorporated herein by reference in their entireties.

Claims (108)

1. A wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station.

2. The wireless LAN system according toclaim 1, wherein the method switching system of the wireless station starts the switching of the connection method when an instruction from outside is received.

3. The wireless LAN system according toclaim 1, wherein the method switching system of the wireless station starts the switching of the connection method when the wireless station is started up.

4. The wireless LAN system according toclaim 1, wherein the notification transmission system of the wireless access point transmits a request reminder data, for reminding the wireless station to request permission of the wireless access point for wireless connection, to the wireless station as the notification data when the announcement data transmitted according to the preset connection method is received and thereafter transmits an association reply, giving the wireless station permission for the wireless connection, to the wireless station when an association request as data for requesting the permission for the wireless connection is received from the wireless station.

5. The wireless LAN system according toclaim 1, wherein the notification transmission system of the wireless access point transmits the notification data to wireless stations transmitting the announcement data satisfying a prescribed condition according to the preset connection method.

6. The wireless LAN system according toclaim 5,

wherein the wireless access point includes announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, and

wherein, after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station transmitting announcement data according to the same connection method as announcement data included in the collected announcement data.

7. The wireless LAN system according toclaim 6,

wherein the wireless access point includes announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, and

wherein the notification transmission system transmits the notification data to a wireless station transmitting announcement data according to the same connection method as announcement data having the highest reception level among the announcement data collected by the announcement collection system.

8. The wireless LAN system according toclaim 6,

wherein the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data,

wherein the announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data, and

wherein the notification transmission system transmits the notification data only to wireless stations transmitting announcement data associated with the same identification data as announcement data already collected by the announcement collection system.

9. The wireless LAN system according toclaim 6,

wherein, after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data included in the collected announcement data, is received from the wireless station.

10. The wireless LAN system according toclaim 1, wherein the notification transmission system of the wireless access point transmits the notification data to a wireless station transmitting announcement data that is selected from the announcement data, transmitted according to the preset connection method, based on an instruction from outside.

11. The wireless LAN system according toclaim 10,

wherein the wireless access point includes announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, and

wherein, after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station transmitting announcement data according to the same connection method as announcement data that is selected from the collected announcement data based on an instruction from outside.

12. The wireless LAN system according toclaim 11,

wherein the wireless access point includes first user selection system which lets a user select one or more wireless stations from the wireless stations transmitting the announcement data collected by the announcement collection system, after the collection of the announcement data by the announcement collection system is finished, and

wherein the notification transmission system transmits the notification data to the one or more wireless stations selected by the user through the first user selection system.

13. The wireless LAN system according toclaim 11,

wherein the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data,

wherein the announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data,

wherein the wireless access point includes second user selection system which lets a user select one or more pieces of the identification data from the identification data associated with the announcement data collected by the announcement collection system, after the collection of the announcement data by the announcement collection system is finished, and

wherein the notification transmission system transmits the notification data to one or more wireless stations identified by the identification data selected by the user through the second user selection system.

14. The wireless LAN system according toclaim 11,

wherein the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data,

wherein the announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data, and

wherein the notification transmission system transmits the notification data only to wireless stations transmitting announcement data associated with the same identification data as announcement data already collected by the announcement collection system.

15. The wireless LAN system according toclaim 11, wherein after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data included in the collected announcement data, is received from the wireless station.

16. The wireless LAN system according toclaim 10, wherein the notification transmission system of the wireless access point is configured to determine the wireless station to which the notification data should be transmitted according to an instruction from a communication terminal which is connected to the wireless access point to communicate data.

17. The wireless LAN system according toclaim 16,

wherein the wireless access point includes:

an announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time and thereby stores data indicating correspondence between the collected announcement data and wireless stations which transmitted the collected announcement data in a storage unit; and

a listing transmission system which transmits listing data, representing a list of wireless stations whose correspondence has been stored in the storage unit by the announcement collection system, to the communication terminal when request data requesting the list of the wireless stations is received from the communication terminal,

wherein after the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more wireless stations selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data corresponding to one of the wireless stations represented by the selection data, is received from the wireless station, and

wherein the communication terminal includes:

a request transmission system which transmits the request data to the wireless access point;

a third user selection system which lets a user select one or more wireless stations from the list represented by the listing data when the listing data is received from the wireless access point after the request data is transmitted to the wireless access point by the request transmission system; and

a selection transmission system which transmits the selection data, representing the one or more wireless stations selected by the user through the third user selection system, to the wireless access point.

18. The wireless LAN system according toclaim 17,

wherein the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data,

wherein the announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data, and

wherein the notification transmission system transmits the notification data only to wireless stations transmitting announcement data associated with the same identification data as announcement data already collected by the announcement collection system.

19. The wireless LAN system according toclaim 17, wherein after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data included in the collected announcement data, is received from the wireless station.

20. The wireless LAN system according toclaim 16,

wherein the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data,

wherein the wireless access point includes:

an announcement collection system which collects the announcement data transmitted according to the preset connection method together with the identification data associated with the announcement data for a prescribed period of time and thereby stores data indicating correspondence between the identification data and wireless stations which transmitted the collected announcement data in a storage unit; and

a listing transmission system which transmits listing data, representing a list of identification data whose correspondence has been stored in the storage unit by the announcement collection system, to the communication terminal when request data requesting the list of the identification data is received from the communication terminal,

wherein after the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more pieces of the identification data selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data corresponding to a piece of the identification data represented by the selection data, is received from the wireless station, and

wherein the communication terminal includes:

a request transmission system which transmits the request data to the wireless access point;

a fourth user selection system which lets a user select one or more pieces of the identification data from the list represented by the listing data when the listing data is received from the wireless access point after the request data is transmitted to the wireless access point by the request transmission system; and

a selection transmission system which transmits the selection data, representing the one or more pieces of identification data selected by the user through the fourth user selection system, to the wireless access point.

21. The wireless LAN system according toclaim 20,

wherein the announcement transmission system of the wireless station transmits the announcement data associating identification data for identifying the wireless station with the announcement data,

wherein the announcement collection system of the wireless access point collects the announcement data together with the identification data associated with the announcement data, and

wherein the notification transmission system transmits the notification data only to wireless stations transmitting announcement data associated with the same identification data as announcement data already collected by the announcement collection system.

22. The wireless LAN system according toclaim 20, wherein after the collection of the announcement data by the announcement collection system is finished, the notification transmission system transmits the notification data to a wireless station when announcement data, transmitted according to the same connection method as announcement data included in the collected announcement data, is received from the wireless station.

23. The wireless LAN system according toclaim 1,

wherein the wireless access point includes encryption switching system which switches an encryption method employed for the data communication with each wireless station, and

wherein in cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the notification data by the notification transmission system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the notification data has been transmitted.

24. The wireless LAN system according toclaim 23,

wherein the wireless access point is connected with a communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

25. The wireless LAN system according toclaim 1,

wherein the notification transmission system of the wireless access point is configured to transmit the notification data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the notification data,

wherein the wireless access point includes encryption switching system which, after the transmission of the notification data by the notification transmission system, switches an encryption method employed for data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key, and

wherein the wireless station includes encryption setting system which, after the reception of the notification data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the notification data.

26. The wireless LAN system according toclaim 23,

wherein the wireless access point is connected with a communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

27. The wireless LAN system according toclaim 26,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication message to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key,

wherein the communication terminal includes confirmation operation system which lets a user who confirmed the authentication message outputted by the wireless station carry out a confirmation operation after the authentication message is transferred to the wireless station by the encryption key transfer system,

wherein the encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system,

wherein the encryption key acquisition system of the wireless station is configured to acquire the authentication message which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key,

wherein the wireless station includes message output system which outputs the authentication message acquired by the encryption key acquisition system, and

wherein the encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication message outputted by the message output system.

28. The wireless LAN system according toclaim 1, wherein the wireless access point includes mode switching system capable of switching the operation mode of the wireless access point to either one selected from a support mode supporting the setting of the connection method of each wireless station by executing the transmission of the notification data by the notification transmission system and a normal mode not supporting the setting of the connection method without executing the transmission of the notification data by the notification transmission system.

29. The wireless LAN system according toclaim 28, wherein the mode switching system of the wireless access point switches the operation mode in response to an instruction from outside.

30. The wireless LAN system according toclaim 28, wherein the mode switching system of the wireless access point switches the operation mode to the normal mode when a prescribed period of time has passed since the switching of the operation mode to the support mode.

31. The wireless LAN system according toclaim 28, wherein the mode switching system of the wireless access point switches the operation mode to the normal mode when the notification data has been transmitted by the notification transmission system for a prescribed number of times since the switching of the operation mode to the support mode.

32. The wireless LAN system according toclaim 1,

wherein the wireless station includes:

content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system; and

non-setting system which prevents the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system when the content judgment system judges that the content of the current settings does not require the new setting.

33. The wireless LAN system according toclaim 1,

wherein the wireless station includes content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the switching by the method switching system, the transmission of the announcement data by the announcement transmission system and the setting by the method setting system,

wherein the announcement transmission system is configured to transmit the announcement data in a state specifying the result of the judgment by the content judgment system on the necessity of the new setting of the connection method, and

wherein the notification transmission system of the wireless access point transmits the notification data only when the announcement data received from the wireless station is data capable of specifying that the new setting of the connection method is necessary.

34. A wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system.

35. The wireless LAN system according toclaim 34, wherein the method notification system of the wireless access point transmits a: request reminder data, for reminding the wireless station to request permission for wireless connection, to the wireless station as the notification data, and thereafter transmits an association reply, giving the wireless station permission for the wireless connection, to the wireless station when an association request as data for requesting the permission for the wireless connection is received from the wireless station.

36. The wireless LAN system according toclaim 34,

wherein the wireless access point includes method switching system which switches the connection method of the wireless access point to each of the connection methods in turn at preset time intervals and thereafter returns the connection method to the connection method preset to the wireless access point,

wherein the reply request system transmits the reply request data according to each connection method switched and set by the method switching system on each switching of the connection method by the method switching system, and

wherein the method notification system transmits the notification data according to the connection method set at the point of the reception of the reply data when the reply data is received between the transmission of the reply request data by the reply request system and the switching of the connection method to the next connection method by the method switching system.

37. The wireless LAN system according toclaim 36, wherein the method switching system of the wireless access point starts the switching of the connection method when an instruction from outside is received.

38. The wireless LAN system according toclaim 36, wherein the reply request system of the wireless access point transmits the reply request data according to the connection method preset to the wireless access point before the switching of the connection method by the method switching system is started.

39. The wireless LAN system according toclaim 34,

wherein the wireless station includes notification collection system which collects the notification data transmitted according to the connection method preset to the wireless station for a prescribed period of time, and

wherein the method setting system sets a connection method notified by notification data having the highest reception level among the notification data collected by the notification collection system as the connection method of the wireless station for the wireless connection to the wireless access point after the collection of the notification data by the notification collection system is finished.

40. The wireless LAN system according toclaim 34, wherein the method notification system of the wireless access point transmits the notification data to wireless stations returning the reply data satisfying a prescribed condition.

41. The wireless LAN system according toclaim 34,

wherein the wireless access point includes reply collection system which collects the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started, and

wherein the method notification system transmits the notification data to a wireless station returning reply data having the highest reception level among the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished.

42. The wireless LAN system according toclaim 34,

wherein the method notification system of the wireless access point transmits the notification data to a wireless station returning reply data that is selected from all the reply data, returned after the transmission of the reply request data by the reply request system is started, based on an instruction from outside.

43. The wireless LAN system according toclaim 32,

wherein the wireless access point includes reply collection system which collects the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started, and

wherein the method notification system transmits the notification data to a wireless station returning reply data that is selected from all the reply data collected by the reply collection system based on an instruction from outside after the collection of the reply data by the reply collection system is finished.

44. The wireless LAN system according toclaim 43,

wherein the wireless access point includes first user selection system which lets a user select one or more wireless stations from the wireless stations returning the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished, and

wherein the method notification system transmits the notification data to the one or more wireless stations selected by the user through the first user selection system.

45. The wireless LAN system according toclaim 43,

wherein the reply transmission system of the wireless station transmits the reply data associating identification data for identifying the wireless station with the reply data,

wherein the reply collection system of the wireless access point collects the reply data together with the identification data associated with the reply data,

wherein the wireless access point includes second user selection system which lets a user select one or more pieces of the identification data from the identification data associated with the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished, and

wherein the method notification system transmits the notification data to one or more wireless stations identified by the identification data selected by the user through the second user selection system.

46. The wireless LAN system according toclaim 42,

wherein the method notification system of the wireless access point is configured to determine the wireless station to which the notification data should be transmitted according to an instruction from a communication terminal which is connected to the wireless access point to communicate data.

47. The wireless LAN system according toclaim 46,

wherein the wireless access point includes:

a reply collection system which collects the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started and thereby stores data indicating correspondence between the collected reply data and wireless stations which transmitted the collected reply data in a storage unit; and

a listing transmission system which transmits listing data, representing a list of wireless stations whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the wireless stations is received from the communication terminal, and

wherein after the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more wireless stations selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the method notification system transmits the notification data to the one or more wireless stations represented by the selection data, and

wherein the communication terminal includes:

a listing request system which transmits the listing request data to the wireless access point;

a third user selection system which lets a user select one or more wireless stations from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system; and

a selection transmission system which transmits the selection data, representing the one or more wireless stations selected by the user through the third user selection system, to the wireless access point.

48. The wireless LAN system according toclaim 46,

wherein the reply transmission system of the wireless station transmits the reply data associating identification data for identifying the wireless station with the reply data,

wherein the wireless access point includes:

a reply collection system which collects the reply data together with the identification data associated with the reply data for a prescribed period of time after the transmission of the reply request data by the reply request system is started and thereby stores data indicating correspondence between the identification data and wireless stations which transmitted the collected reply data in a storage unit; and

a listing transmission system which transmits listing data, representing a list of identification data whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the identification data is received from the communication terminal,

wherein, after the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more pieces of the identification data selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the method notification system transmits the notification data to one or more wireless stations corresponding to the one or more pieces of identification data represented by the selection data, and

wherein the communication terminal includes:

a listing request system which transmits the listing request data to the wireless access point;

a fourth user selection system which lets a user select one or more pieces of the identification data from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system; and

a selection transmission system which transmits the selection data, representing the one or more pieces of identification data selected by the user through the fourth user selection system, to the wireless access point.

49. The wireless LAN system according toclaim 34,

wherein the wireless access point includes encryption switching system which switches an encryption method employed for the data communication with each wireless station, and

wherein, in cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the notification data by the method notification system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the notification data has been transmitted.

50. The wireless LAN system according toclaim 49,

wherein the wireless access point is connected with a communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system, and

the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

51. The wireless LAN system according toclaim 50,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication signal to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key,

wherein the communication terminal includes confirmation operation system which lets a user who confirmed the authentication signal outputted by the wireless station carry out a confirmation operation after the authentication signal is transferred to the wireless station by the encryption key transfer system,

wherein the encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system,

wherein the encryption key acquisition system of the wireless station is configured to acquire the authentication signal which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key,

wherein the wireless station includes signal output system which outputs the authentication signal acquired by the encryption key acquisition system, and

wherein the encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication signal outputted by the signal output system.

52. The wireless LAN system according toclaim 50,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication signal which indicates transferring of the first encryption key to the wireless station by the public key cryptosystem, and

wherein the wireless station includes a signal output system which outputs the authentication signal acquired by the encryption key acquisition system.

53. The wireless LAN system according toclaim 33,

wherein the method notification system of the wireless access point is configured to transmit the notification data attaching a second encryption key, which is different from a first encryption key being employed for encrypting, the data communication by the wireless access point, to the notification data,

wherein the wireless access point includes encryption switching system which, after the transmission of the notification data by the method notification system, switches an encryption method employed for data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key, and

wherein the wireless station includes encryption setting system which, after the reception of the notification data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the notification data.

54. The wireless LAN system according toclaim 53,

wherein the wireless access point is connected with a communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system, and

the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

55. The wireless LAN system according toclaim 54,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication signal which indicates transferring of the first encryption key to the wireless station by the public key cryptosystem, and

wherein the wireless station includes a signal output system which outputs the authentication signal acquired by the encryption key acquisition system.

56. The wireless LAN system according toclaim 54,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication signal to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key,

wherein the communication terminal includes confirmation operation system which lets a user who confirmed the authentication signal outputted by the wireless station carry out a confirmation operation after the authentication signal is transferred to the wireless station by the encryption key transfer system,

wherein the encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system,

wherein the encryption key acquisition system of the wireless station is configured to acquire the authentication signal which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key,

wherein the wireless station includes signal output system which outputs the authentication signal acquired by the encryption key acquisition system, and

wherein the encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication signal outputted by the signal output system.

57. The wireless LAN system according toclaim 33,

wherein the wireless access point includes mode switching system capable of switching the operation mode of the wireless access point to either one selected from a support mode supporting the setting of the connection method of each wireless station by executing the transmission of the notification data by the method notification system and a normal mode not supporting the setting of the connection method without executing the transmission of the notification data by the method notification system.

58. The wireless LAN system according toclaim 57,

wherein the mode switching system of the wireless access point switches the operation mode in response to an instruction from outside.

59. The wireless LAN system according toclaim 57,

wherein the mode switching system of the wireless access point switches the operation mode to the normal mode when a prescribed period of time has passed since the switching of the operation mode to the support mode.

60. The wireless LAN system according toclaim 57,

wherein the mode switching system of the wireless access point switches the operation mode to the normal mode when the notification data has been transmitted by the method notification system for a prescribed number of times since the switching of the operation mode to the support mode.

61. The wireless LAN system according toclaim 33,

wherein the wireless station includes:

a content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the reply by the reply transmission system and the setting by the method setting system; and

an operation suspension system which prevents the reply by the reply transmission system and/or the setting by the method setting system when the content judgment system judges that the content of the current settings does not require the new setting.

62. The wireless LAN system according toclaim 33,

wherein the wireless station includes content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the reply by the reply transmission system and the setting by the method setting system,

wherein the reply transmission system is configured to transmit the reply data in a state specifying the result of the judgment by the content judgment system on the necessity of the new setting of the connection method, and

wherein the method notification system of the wireless access point transmits the notification data only when the reply data received from the wireless station is data capable of specifying that the new setting of the connection method is necessary.

63. A wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point.

64. The wireless LAN system according toclaim 63,

wherein the announcement transmission system of the wireless access point is configured to transmit data for requesting a reply made according to the particular connection method as the announcement data,

wherein the wireless access point includes connection permission system which establishes the wireless connection with the wireless station by transmitting a request reminder data for letting the wireless station request permission for the wireless connection to the wireless access point when reply data returned from the wireless station according to the announcement data is received after the transmission of the announcement data is started by the announcement transmission system and thereafter transmitting connection permission data indicating permission for the wireless connection to the wireless access point when permission request data as data for requesting the permission for the wireless connection is received from the wireless station, and

wherein the wireless station includes:

a reply system which returns the reply data representing the reply requested by the announcement data to the wireless access point according to the particular connection method announced by the announcement data when the announcement data is received from the wireless access point; and

a connection establishment system which establishes the wireless connection with the wireless access point via the transmission of the permission request data and the reception of the connection permission data when the request reminder data transmitted by the wireless access point is received after the reply system transmitted the reply data to the wireless access point.

65. The wireless LAN system according toclaim 63,

wherein the wireless access point includes method switching system which temporarily switches the connection method of the wireless access point to each of the connection methods, and

wherein the announcement transmission system transmits the announcement data according to each connection method switched and set by the method switching system during each period in which the connection method is temporarily switched by the method switching system to the connection method.

66. The wireless LAN system according toclaim 65, wherein the method switching system of the wireless access point starts the switching of the connection method when an instruction from outside is received.

67. The wireless LAN system according toclaim 66, wherein the announcement transmission system of the wireless access point transmits the announcement data according to a preset connection method before the switching of the connection method by the method switching system is started.

68. The wireless LAN system according toclaim 63,

wherein the wireless station includes announcement collection system which collects the announcement data transmitted according to the preset connection method for a prescribed period of time, and

wherein the method setting system sets a connection method announced by announcement data having the highest reception level among the announcement data collected by the announcement collection system as the connection method of the wireless station for the wireless connection to the wireless access point after the collection of the announcement data by the announcement collection system is finished.

69. The wireless LAN system according toclaim 63, wherein the connection permission system of the wireless access point transmits the request reminder data to wireless stations returning the reply data satisfying a prescribed condition.

70. The wireless LAN system according toclaim 69,

wherein the wireless access point includes reply collection system which collects the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started, and

wherein the connection permission system transmits the request reminder data to a wireless station returning reply data having the highest reception level among the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished.

71. The wireless LAN system according toclaim 63, wherein the connection permission system of the wireless access point transmits the request reminder data to a wireless station returning reply data that is selected from all the reply data, returned after the transmission of the announcement data by the announcement transmission system is started, based on an instruction from outside.

72. The wireless LAN system according toclaim 71,

wherein the wireless access point includes reply collection system which collects the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started, and

wherein the connection permission system transmits the request reminder data to a wireless station returning reply data that is selected from all the reply data collected by the reply collection system based on an instruction from outside after the collection of the reply data by the reply collection system is finished.

73. The wireless LAN system according toclaim 72,

wherein the wireless access point includes first user selection system which lets a user select one or more wireless stations from the wireless stations returning the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished, and

wherein the connection permission system transmits the request reminder data to the one or more wireless stations selected by the user through the first user selection system.

74. The wireless LAN system according toclaim 72,

wherein the reply system of the wireless station transmits the reply data associating identification data for identifying the wireless station with the reply data,

wherein the reply collection system of the wireless access point collects the reply data together with the identification data associated with the reply data,

wherein the wireless access point includes second user selection system which lets a user select one or more pieces of the identification data from the identification data associated with the reply data collected by the reply collection system, after the collection of the reply data by the reply collection system is finished, and

wherein the connection permission system transmits the request reminder data to one or more wireless stations identified by the identification data selected by the user through the second user selection system.

75. The wireless LAN system according toclaim 71, wherein the connection permission system of the wireless access point is configured to determine the wireless station to which the request reminder data should be transmitted according to an instruction from a communication terminal which is connected to the wireless access point to communicate data.

76. The wireless LAN system according toclaim 75.

wherein the wireless access point includes:

a reply collection system which collects the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started and thereby stores data indicating correspondence between the collected reply data and wireless stations which transmitted the collected reply data in a storage unit; and

a listing transmission system which transmits listing data, representing a list of wireless stations whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the wireless stations is received from the communication terminal,

wherein, after the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more wireless stations selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the connection permission system transmits the notification data to the one or more wireless stations represented by the selection data, and

wherein the communication terminal includes:

a listing request system which transmits the listing request data to the wireless access point;

a third user selection system which lets a user select one or more wireless stations from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system; and

a selection transmission system which transmits the selection data, representing the one or more wireless stations selected by the user through the third user selection system, to the wireless access point.

77. The wireless LAN system according toclaim 75,

wherein the reply system of the wireless station transmits the reply data associating identification data for identifying the wireless station with the reply data,

wherein the wireless access point includes:

a reply collection system which collects the reply data together with the identification data associated with the reply data for a prescribed period of time after the transmission of the announcement data by the announcement transmission system is started and thereby stores data indicating correspondence between the identification data and wireless stations which transmitted the collected reply data in a storage unit; and

a listing transmission system which transmits listing data, representing a list of identification data whose correspondence has been stored in the storage unit by the reply collection system, to the communication terminal when listing request data requesting the list of the identification data is received from the communication terminal, and

wherein, after the listing data is transmitted to the communication terminal by the listing transmission system and selection data, representing one or more pieces of the identification data selected at the communication terminal from the list represented by the listing data, is received from the communication terminal, the connection permission system transmits the request reminder data to one or more wireless stations corresponding to the one or more pieces of identification data represented by the selection data, and

wherein the communication terminal includes:

a listing request system which transmits the listing request data to the wireless access point;

a fourth user selection system which lets a user select one or more pieces of the identification data from the list represented by the listing data when the listing data is received from the wireless access point after the listing request data is transmitted to the wireless access point by the listing request system; and

a selection transmission system which transmits the selection data, representing the one or more wireless stations selected by the user through the fourth user selection system, to the wireless access point.

78. The wireless LAN system according toclaim 63,

wherein the wireless access point includes encryption switching system which switches an encryption method employed for the data communication with each wireless station, and

wherein in cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the request reminder data by the connection permission system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the request reminder data has been transmitted.

79. The wireless LAN system according toclaim 78,

wherein the wireless access point is connected with a communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

80. The wireless LAN system according toclaim 79,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication message to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key,

wherein the communication terminal includes confirmation operation system which lets a user who confirmed the authentication message outputted by the wireless station carry out a confirmation operation after the authentication message is transferred to the wireless station by the encryption key transfer system,

wherein the encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system,

wherein the encryption key acquisition system of the wireless station is configured to acquire the authentication message which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key,

wherein the wireless station includes message output system which outputs the authentication message acquired by the encryption key acquisition system, and

wherein the encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication message outputted by, the message output system.

81. The wireless LAN system according toclaim 63,

wherein the connection permission system of the wireless access point is configured to transmit the request reminder data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the request reminder data,

wherein the wireless access point includes encryption switching system which, after the transmission of the request reminder data by the connection permission system, switches an encryption method employed for data communication with each wireless station to which the request reminder data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key, and

wherein the wireless station includes encryption setting system which, after the reception of the request reminder data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the request reminder data.

82. The wireless LAN system according toclaim 81,

wherein the wireless access point is connected with a communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

83. The wireless LAN system according toclaim 82,

wherein the encryption key transfer system of the communication terminal is configured to transfer an authentication message to the wireless station by the public key cryptosystem prior to the transfer of the first encryption key,

wherein the communication terminal includes confirmation operation system which lets a user who confirmed the authentication message outputted by the wireless station carry out a confirmation operation after the authentication message is transferred to the wireless station by the encryption key transfer system,

wherein the encryption key transfer system is configured to transfer the first encryption key when the confirmation operation is carried out through the confirmation operation system,

wherein the encryption key acquisition system of the wireless station is configured to acquire the authentication message which is transferred from the communication terminal by the public key cryptosystem prior to the first encryption key,

wherein the wireless station includes message output system which outputs the authentication message acquired by the encryption key acquisition system, and

wherein the encryption key acquisition system acquires the first encryption key which is transferred from the communication terminal after the confirmation operation to the communication terminal is carried out by the user confirming the authentication message outputted by the message output system.

84. The wireless LAN system according toclaim 63,

wherein the wireless access point includes mode switching system capable of switching the operation mode of the wireless access point to either one selected from a support mode supporting the setting of the connection method of each wireless station by executing the transmission of the announcement data by the announcement transmission system and a normal mode not supporting the setting of the connection method without executing the transmission of the announcement data by the announcement transmission system.

85. The wireless LAN system according toclaim 84, wherein the mode switching system of the wireless access point switches the operation mode in response to an instruction from outside.

86. The wireless LAN system according toclaim 84, wherein the mode switching system of the wireless access point switches the operation mode to the normal mode when a prescribed period of time has passed since the switching of the operation mode to the support mode.

87. The wireless LAN system according toclaim 84, wherein the mode switching system of the wireless access point switches the operation mode to the normal mode when the announcement data has been transmitted by the announcement transmission system for a prescribed number of times since the switching of the operation mode to the support mode.

88. The wireless LAN system according toclaim 63,

wherein the wireless station includes:

a content judgment system which judges whether or not content of current settings regarding the connection method for the wireless connection to the wireless access point requires new setting of the connection method for the wireless connection to the wireless access point via the setting by the method setting system; and

an operation suspension system which prevents the setting by the method setting system when the content judgment system judges that the content of the current settings does not require the new setting.

89. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless station includes:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

wherein the wireless access point includes a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station,

wherein the notification transmission system of the wireless access point transmits the notification data to a wireless station transmitting announcement data that is selected from the announcement data, transmitted according to the preset connection method, based on an instruction from outside, and

wherein the notification transmission system of the wireless access point is configured to determine the wireless station to which the notification data should be transmitted according to an instruction from the communication terminal which is connected to the wireless access point to communicate data.

90. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station,

wherein the wireless access point includes encryption switching system which switches an encryption method employed for the data communication with each wireless station, and

wherein in cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the notification data by the notification transmission system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the notification data has been transmitted,

wherein the wireless access point is connected with the communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

91. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station,

wherein the notification transmission system of the wireless access point is configured to transmit the notification data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the notification data,

wherein the wireless access point includes encryption switching system which, after the transmission of the notification data by the notification transmission system, switches an encryption method employed for data communication with each wireless station to which the notification data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key, and

wherein the wireless station includes encryption setting system which, after the reception of the notification data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the notification data,

wherein the wireless access point is connected with the communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

92. A communication terminal which functions as the wireless station of a wireless LAN system in which data communication between the wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station.

93. A communication terminal which functions as the wireless access point of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and the wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station.

94. A computer program product comprising computer readable and executable instructions that cause a computer to function as a wireless station of a wireless LAN system in which data communication between the wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including:

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station.

95. A computer program product comprising computer readable and executable instructions that cause a computer to function as a wireless access point of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and the wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

the wireless station including;

a method switching system that switches the connection method of the wireless station for the wireless connection to the wireless access point to each of the connection methods in turn at preset time intervals;

an announcement transmission system that transmits announcement data, for announcing the switched connection method to devices around the wireless station, according to the switched connection method on each switching of the connection method by the method switching system; and

a method setting system that stops the connection method switching by the method switching system when notification data, for notifying the wireless station that wireless connection by use of the same connection method as the transmitted announcement data is possible, is received during a period between the transmission of the announcement data by the announcement transmission system and the connection method switching by the method switching system to the next connection method and thereby sets the connection method at the point of the stop of the connection method switching as the connection method for the wireless connection to the wireless access point,

the wireless access point including a notification transmission system that transmits the notification data to the wireless station when the announcement data transmitted according to the preset connection method is received from the wireless station.

96. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system,

wherein the method notification system of the wireless access point transmits the notification data to a wireless station returning reply data that is selected from all the reply data, returned after the transmission of the reply request data by the reply request system is started, based on an instruction from outside, and

wherein the method notification system of the wireless access point is configured to determine the wireless station to which the notification data should be transmitted according to an instruction from the communication terminal which is connected to the wireless access point to communicate data.

97. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system,

wherein the wireless access point includes encryption switching system which switches an encryption method employed for the data communication with each wireless station, and

wherein, in cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the notification data by the method notification system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the notification data has been transmitted,

wherein the wireless access point is connected with the communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system, and

the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

98. A communication terminal which functions as a wireless station of a wireless LAN system in which data communication between the wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system.

99. A communication terminal which functions as a wireless access point of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and the wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system.

100. A program product comprising computer readable and executable instructions that cause a computer to function as a wireless station of a wireless LAN system in which data communication between the wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system.

101. A program product comprising computer readable and executable instructions that cause a computer to function as a wireless access point of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and the wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes:

a reply request system which transmits reply request data, for requesting a reply, to the wireless station according to each of the connection methods; and

a method notification system which transmits notification data, for notifying the wireless station of the connection method preset to the wireless access point, to the wireless station according to the same connection method as reply data when the reply data as the reply to the reply request data is received after the transmission of the reply request data by the reply request system, and

wherein the wireless station includes:

a reply transmission system which transmits the reply data to the wireless access point when the request data transmitted from the wireless access point according to a connection method preset to the wireless station is received; and

a method setting system which sets the connection method of the wireless station for the wireless connection to the wireless station to the connection method notified by the notification data when the notification data transmitted according to the connection method preset to the wireless station is received after the transmission of the reply request data by the reply transmission system.

102. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point,

wherein the connection permission system of the wireless access point transmits the request reminder data to a wireless station returning reply data that is selected from all the reply data, returned after the transmission of the announcement data by the announcement transmission system is started, based on an instruction from outside, and

wherein the connection permission system of the wireless access point is configured to determine the wireless station to which the request reminder data should be transmitted according to an instruction from the communication terminal which is connected to the wireless access point to communicate data.

103. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point,

wherein the wireless access point includes encryption switching system which switches an encryption method employed for the data communication with each wireless station, and

wherein in cases where the wireless access point has been set to a state for executing the data communication by encrypting data with a first encryption key after the transmission of the request reminder data by the connection permission system, the encryption switching system switches the encryption method to a method executing the data communication without encryption only for data communication with each wireless station to which the request reminder data has been transmitted,

wherein the wireless access point is connected with the communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

104. A communication terminal of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point,

wherein the connection permission system of the wireless access point is configured to transmit the request reminder data attaching a second encryption key, which is different from a first encryption key being employed for encrypting the data communication by the wireless access point, to the request reminder data,

wherein the wireless access point includes encryption switching system which, after the transmission of the request reminder data by the connection permission system, switches an encryption method employed for data communication with each wireless station to which the request reminder data has been transmitted, to a method executing the data communication by encrypting data with the second encryption key, and

wherein the wireless station includes encryption setting system which, after the reception of the request reminder data from the wireless access point, sets the wireless station to execute the data communication with the wireless access point by encrypting data with the second encryption key attached to the request reminder data,

wherein the wireless access point is connected with the communication terminal capable of data communication with the wireless access point,

wherein the wireless station includes:

an encryption key acquisition system which acquires the first encryption key from the communication terminal via the wireless access point by the public key cryptosystem; and

an encryption alteration system which alters settings of the wireless station so that data communication with the wireless access point will be executed employing the encryption with the first encryption key, by releasing the wireless connection with the wireless access point and reestablishing the wireless connection employing the encryption with the first encryption key when the first encryption key is acquired from the communication terminal by the encryption key acquisition system,

wherein the communication terminal includes encryption key transfer system which transfers the first encryption key to the wireless station via the wireless access point by the public key cryptosystem, and

wherein the encryption switching system of the wireless access point does not execute the switching of the encryption method after the wireless connection with the wireless station is released.

105. A wireless station of a wireless LAN system in which data communication between the wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point.

106. A wireless access point of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and the wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point.

107. A computer program product comprising computer readable and executable instructions that cause a computer to function as a wireless station of a wireless LAN system in which data communication between the wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and a wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data, for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point.

108. A computer program product comprising computer readable and executable instructions that cause a computer to function as a wireless access point of a wireless LAN system in which data communication between a wireless station whose connection method as a method for wireless connection can be set to one of a plurality of connection methods and the wireless access point whose connection method has been preset to one of the connection methods is made possible by setting the connection method of the wireless station to a method identical with the connection method of the wireless access point,

wherein the wireless access point includes announcement transmission system which transmits announcement data for announcing that the connection method of the wireless access point has been set to a particular one selected from the connection methods, according to each of the connection methods, and

wherein the wireless station includes method setting system which sets the connection method of the wireless station for the wireless connection to the wireless access point to the particular connection method announced by the announcement data when the announcement data transmitted according to a preset connection method is received from the wireless access point.

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