CN1438789A - Method for swhiching over between swith-in points moving terminal in winefree local network - Google Patents

Abstract

Translated fromChinese

本发明一种无线局域网移动终端在AP间切换的方法，其特点是，包括以下步骤：1)用户在保持和当前AP连接的同时，先测量其他AP的信号强度和质量，然后根据测量值决定是否切换和切换到哪一个AP；2)用户与选定的AP进行连接；3)建立连接后，将用户标识上报给无线网关；4)无线网关查找用户列表；5)无线网关根据接入用户的AP地址，向原AP发出切换通知；6)原AP接到通知后将该用户的信息传送到新AP；7)同时无线网关通知新AP该用户为切换用户，并将相关信息发送给新AP；8)新AP接入该用户，向无线网关发确认信息；9)无线网关接到切换成功确认消息以后，更新接入列表中的AP地址，通知原AP删除该用户状态信息。该方法可以实现保证Qos切换，并能对AP身份进行认证，防止假冒AP的攻击。

A method for switching between APs in a wireless local area network mobile terminal of the present invention is characterized in that it comprises the following steps: 1) the user first measures the signal strength and quality of other APs while maintaining a connection with the current AP, and then decides according to the measured value Whether to switch and which AP to switch to; 2) The user connects to the selected AP; 3) After the connection is established, the user ID is reported to the wireless gateway; 4) The wireless gateway searches the user list; 6) After receiving the notification, the original AP transmits the user's information to the new AP; 7) At the same time, the wireless gateway notifies the new AP that the user is a switching user, and sends the relevant information to the new AP 8) the new AP accesses the user, and sends confirmation information to the wireless gateway; 9) the wireless gateway updates the AP address in the access list after receiving the handover success confirmation message, and notifies the original AP to delete the user status information. The method can realize guaranteed Qos switching, and can authenticate the identity of the AP, so as to prevent the attack of the counterfeit AP.

Description

Translated fromChinese

无线局域网中移动终端在接入点间切换的方法Method for Mobile Terminal Switching Between Access Points in Wireless Local Area Network

技术领域technical field

本发明涉及无线局域网中移动终端在接入点(AP)间切换的方法。The invention relates to a method for a mobile terminal to switch between access points (APs) in a wireless local area network.

背景技术Background technique

无线局域网利用无线射频(radio frequency，RF)技术在空中传输数据、话音和视频信号。相对于传统布线网络，无线局域网具有安装便捷，使用灵活，经济节约和易于扩展等特点，因而日益受到重视。无线局域网的终端可移动性是其相对于布线网络的重要优势之一。移动终端要想在较大的范围内实现对移动终端用户透明的移动，势必要实现AP(接入点)间的切换，如附图1所示。Wireless local area network uses radio frequency (radio frequency, RF) technology to transmit data, voice and video signals in the air. Compared with the traditional wiring network, wireless local area network has the characteristics of convenient installation, flexible use, economical saving and easy expansion, so it has been paid more and more attention. Terminal mobility of WLAN is one of its important advantages over wired network. If the mobile terminal wants to move transparently to the mobile terminal user within a relatively large range, it is necessary to realize switching between APs (Access Points), as shown in FIG. 1 .

传统的AP间切换方法是：在移动终端与AP通信期间，如果终端移出了AP的覆盖范围，或者由于干扰，通信质量无法保证，就需要切换到其他通信质量较好的AP。在执行切换时，移动终端首先向新AP发出连接请求，并向新AP通知原来连接AP(原AP)的位置。由新AP通知原AP断开与该移动终端的连接，并从原AP得到移动终端用户的状态信息。The traditional handover method between APs is: during the communication between the mobile terminal and the AP, if the terminal moves out of the coverage of the AP, or the communication quality cannot be guaranteed due to interference, it needs to be handed over to other APs with better communication quality. When performing handover, the mobile terminal first sends a connection request to the new AP, and notifies the new AP of the location of the originally connected AP (original AP). The new AP notifies the original AP to disconnect from the mobile terminal, and obtains the status information of the mobile terminal user from the original AP.

传统切换方法采用分布式对等的切换结构，所有的信息交互和控制都由两个AP配合完成。因此AP的处理任务相对比较复杂。而且，传统方法如果切换过程中出现错误，不容易自动恢复原有状态，容错能力不强。The traditional switching method adopts a distributed peer-to-peer switching structure, and all information exchange and control are completed by the cooperation of two APs. Therefore, the processing task of the AP is relatively complicated. Moreover, if an error occurs during the switching process in the traditional method, it is not easy to automatically restore the original state, and the fault tolerance is not strong.

由于AP上不会存储移动终端用户的所有信息，比如用户质量需求(Qos)信息，因此，传统的切换方法很难实现保证Qos的切换。Since all information of mobile terminal users, such as user quality requirement (Qos) information, is not stored on the AP, it is difficult to implement handover with guaranteed Qos in the traditional handover method.

传统的切换方法，由移动终端用户来提供原AP的位置信息。而在某些情况下，移动终端用户提供的信息并不正确。比如户快速在两个AP间切换时，这种情况经常发生。如果这个信息提供错误，会造成切换失败。In the traditional handover method, the mobile terminal user provides the location information of the original AP. And in some cases, the information provided by the mobile terminal user is not correct. For example, when a user quickly switches between two APs, this situation often occurs. If this information is provided incorrectly, the switchover will fail.

另外，传统切换方法由新AP来通知原AP断开连接，并得到移动终端用户的状态信息，这会产生安全隐患。恶意的攻击者可以假冒AP，获取移动终端用户敏感信息。In addition, in the traditional handover method, the new AP notifies the original AP to disconnect and obtain the status information of the mobile terminal user, which will cause security risks. Malicious attackers can pretend to be APs to obtain sensitive information of mobile terminal users.

发明内容Contents of the invention

本发明的目的是为了克服现有的无线局域网中移动终端切换的方法，而提供的一种具有集中控制结构、切换过程由无线网关或者专用的切换控制服务器集中控制的、新的无线局域网中移动终端AP间切换的方法。The purpose of the present invention is to overcome the existing mobile terminal handover method in the wireless local area network, and provide a new mobile terminal AP in the wireless local area network with a centralized control structure, the handover process is centrally controlled by the wireless gateway or a dedicated handover control server method to switch between.

本发明的目的是这样实现的：一种无线局域网中移动终端在接入点间切换的方法，其特征在于，包括以下步骤：The object of the present invention is achieved like this: a kind of method that mobile terminal switches between access points in the wireless local area network, it is characterized in that, comprises the following steps:

1)移动终端用户在保持和当前接入点连接的同时，先测量其他接入点的信号强度和质量，然后由用户根据测量值决定是否切换和切换到哪一个新接入点；1) While maintaining the connection with the current access point, the mobile terminal user first measures the signal strength and quality of other access points, and then the user decides whether to switch and which new access point to switch to according to the measured value;

2)移动终端用户与选定的新接入点进行通信连接；2) The mobile terminal user communicates with the selected new access point;

3)移动终端用户与新接入点建立通信连接后，接入点将移动终端用户标识上报给无线网关；3) After the mobile terminal user establishes a communication connection with the new access point, the access point reports the mobile terminal user identification to the wireless gateway;

4)无线网关查找接入移动终端用户列表，得到该移动终端用户原接入点的地址；4) The wireless gateway searches the access mobile terminal user list, and obtains the address of the original access point of the mobile terminal user;

5)无线网关根据列表中存储的接入点地址，向原接入点发出切换通知；5) The wireless gateway sends a switching notification to the original access point according to the access point address stored in the list;

6)原接入点接到通知后将该移动终端用户的缓存数据、状态信息直接传送到新接入点；6) After receiving the notification, the original access point directly transmits the cached data and status information of the mobile terminal user to the new access point;

7)同时无线网关通知新接入点该移动终端用户为切换移动终端用户，并将该移动终端用户的相关信息发送给该新接入点；7) At the same time, the wireless gateway notifies the new access point that the mobile terminal user is a handover mobile terminal user, and sends the relevant information of the mobile terminal user to the new access point;

8)新接入点接到通知后，接入该移动终端用户；经新接入点判断切换成功后，向无线网关发确认信息；8) After the new access point receives the notification, it accesses the mobile terminal user; after the new access point judges that the handover is successful, it sends a confirmation message to the wireless gateway;

9)无线网关接到切换成功确认消息以后，更新接入移动终端用户列表中的接入点地址，通知原接入点删除该移动终端用户状态信息。9) After receiving the handover success confirmation message, the wireless gateway updates the address of the access point in the mobile terminal user list, and notifies the original access point to delete the mobile terminal user status information.

上述无线局域网中移动终端在接入点间切换的方法，其中，所述的接入点切换过程中，信息的接收方可对收到的交互信息进行确认，在确认后，再开始下一步动作；如果确认消息超时，则恢复到原有状态。The above-mentioned method for switching a mobile terminal between access points in a wireless local area network, wherein, during the switching process of the access point, the information receiver can confirm the received interaction information, and start the next step after confirmation; If the confirmation message times out, restore to the original state.

上述无线局域网中移动终端在接入点间切换的方法，其中，步骤5)中所述的通知中包括移动终端用户终端地址和新接入点地址。In the above method for switching a mobile terminal between access points in a wireless local area network, the notification in step 5) includes the user terminal address of the mobile terminal and the address of the new access point.

上述无线局域网中移动终端在接入点间切换的方法，其中，步骤6)所述的原接入点传送该移动终端用户的缓存数据、状态信息可由无线网关转发。In the above-mentioned method for switching a mobile terminal between access points in a wireless local area network, the buffered data and status information of the mobile terminal user transmitted by the original access point in step 6) can be forwarded by the wireless gateway.

上述无线局域网中移动终端在接入点间切换的方法，其中，步骤6)中所述的状态信息包括加密密钥。In the above method for switching a mobile terminal between access points in a wireless local area network, the state information in step 6) includes an encryption key.

上述无线局域网中移动终端在接入点间切换的方法，其中，步骤7)中所述的相关信息包括移动终端用户质量需求信息。In the above-mentioned method for switching a mobile terminal between access points in a wireless local area network, the related information in step 7) includes mobile terminal user quality requirement information.

上述无线局域网中移动终端在接入点间切换的方法，其中，步骤7)无线网关将该移动终端用户的相关信息发送给新接入点的同时可下发控制报文，通知交换设备修改对应于该地址的转发路由。In the above-mentioned method for switching a mobile terminal between access points in a wireless local area network, step 7) the wireless gateway may issue a control message while sending the relevant information of the mobile terminal user to the new access point, and notify the switching device to modify the corresponding The forwarding route for this address.

上述无线局域网中移动终端在接入点间切换的方法，其中，所述的为验证控制成功，可以以移动终端用户地址为目的地址，发测试报文。In the above-mentioned method for switching a mobile terminal between access points in a wireless local area network, in order to verify that the control is successful, a test message may be sent with the user address of the mobile terminal as the destination address.

上述无线局域网中移动终端在接入点间切换的方法，其中，步骤8)中所述的判断切换是否成功的方法是：由无线网关发送测试报文，接入点收到测试报文后则可以确认切换成功。The above-mentioned method for switching a mobile terminal between access points in a wireless local area network, wherein the method for judging whether the handover is successful described in step 8) is: a test message is sent by a wireless gateway, and the access point can receive the test message after receiving the test message. Confirm that the switchover is successful.

上述无线局域网中移动终端在接入点间切换的方法，其中，所述的无线网关可以对原接入点和新接入点进行认证，并对交互信息进行加密。In the above method for switching a mobile terminal between access points in a wireless local area network, the wireless gateway can authenticate the original access point and the new access point, and encrypt the interaction information.

由于本发明采用了以上的技术方案，将一部分控制和交互任务由服务器来完成，因此，相对于传统的切换方法，AP(接入点)的处理任务相对简单。而且，这种结构容错能力相对较强，即使出现错误，也可以容易的恢复状态。同时，这种方法可以实现保证Qos切换，并能对AP身份进行认证，防止假冒AP的攻击。同时，切换测量和判决都由用户来完成，减少了AP的处理任务，降低了AP复杂度。Since the present invention adopts the above technical solution, a part of the control and interaction tasks are completed by the server, therefore, compared with the traditional handover method, the processing tasks of the AP (access point) are relatively simple. Moreover, this structure has relatively strong fault tolerance, and even if an error occurs, the state can be easily restored. At the same time, this method can realize the guaranteed Qos switching, and can authenticate the identity of the AP, so as to prevent the attack of fake AP. At the same time, the handover measurement and decision are all completed by the user, which reduces the processing tasks of the AP and reduces the complexity of the AP.

附图说明Description of drawings

本发明的具体性能特征由以下的实施例及其附图进一步描述。The specific performance characteristics of the present invention are further described by the following examples and accompanying drawings.

图1是现有技术移动终端在两个AP间切换的结构示意图。FIG. 1 is a schematic structural diagram of a mobile terminal switching between two APs in the prior art.

图2是本发明切换信息交互流程图。Fig. 2 is a flowchart of handover information interaction in the present invention.

具体实施方式Detailed ways

本发明无线局域网移动终端在接入点间切换的方法，包括以下步骤：The method for the wireless local area network mobile terminal of the present invention to switch between access points comprises the following steps:

1)移动终端用户在保持和当前接入点连接的同时，先测量其他接入点的信号强度和质量，然后由用户根据测量值决定是否切换和切换到哪一个接入点；1) While maintaining the connection with the current access point, the mobile terminal user first measures the signal strength and quality of other access points, and then the user decides whether to switch and which access point to switch to according to the measured value;

2)移动终端用户与选定的接入点进行连接；2) The mobile terminal user connects to the selected access point;

3)与接入点建立连接后，接入点将移动终端用户标识上报给无线网关；3) After establishing a connection with the access point, the access point reports the user identification of the mobile terminal to the wireless gateway;

4)无线网关查找接入移动终端用户列表，得到该移动终端用户原接入点的地址；4) The wireless gateway searches the access mobile terminal user list, and obtains the address of the original access point of the mobile terminal user;

5)无线网关根据接入移动终端用户列表中存储的接入点地址，向原接入点发出切换通知；5) The wireless gateway sends a switching notification to the original access point according to the access point address stored in the mobile terminal user list;

6)原接入点接到通知后将该移动终端用户的缓存数据、状态信息直接传送到新接入点；6) After receiving the notification, the original access point directly transmits the cached data and status information of the mobile terminal user to the new access point;

7)同时无线网关通知新接入点该移动终端用户为切换移动终端用户，并将该移动终端用户的相关信息发送给该新接入点。7) At the same time, the wireless gateway notifies the new access point that the mobile terminal user is a switching mobile terminal user, and sends the relevant information of the mobile terminal user to the new access point.

8)新接入点接到通知后，接入该移动终端用户；经新接入点判断切换成功后，向无线网关发确认信息；8) After the new access point receives the notification, it accesses the mobile terminal user; after the new access point judges that the handover is successful, it sends a confirmation message to the wireless gateway;

9)无线网关接到切换成功确认消息以后，更新接入移动终端用户列表中的接入点地址，通知原接入点删除该移动终端用户状态信息。9) After receiving the handover success confirmation message, the wireless gateway updates the address of the access point in the mobile terminal user list, and notifies the original access point to delete the mobile terminal user status information.

在以上过程中，交互信息都可以有相应的确认信息。只有收到确认消息，才开始下一步。如果确认消息超时，则恢复到原有状态。同时，为了保证安全，无线网关可以对原AP和新AP进行认证，并对交互信息进行加密。In the above process, the interactive information may have corresponding confirmation information. Only after receiving a confirmation message can the next step be started. If the confirmation message times out, restore to the original state. At the same time, in order to ensure security, the wireless gateway can authenticate the original AP and the new AP, and encrypt the exchanged information.

本发明需要AP与无线网关或专用切换控制服务器配合完成。整个切换过程由无线网关来控制。每当新移动终端用户与AP建立连接，通过接入认证以后，无线网关将该移动终端用户标识，如所在终端地址以及连接AP地址和相关信息存入接入移动终端用户列表。相关信息包括保持移动终端用户业务连续性所需的一些信息，比如Qos信息。移动终端用户下线以后，这些信息就被删除。用户在保持和当前AP连接的同时，测量其他AP的信号强度和质量。由用户根据测量值决定是否切换和切换到哪一个AP。用户切换到新AP，与新AP建立连接时，AP首先将该移动终端用户标识上报给无线网关，由无线网关在接入移动终端用户列表中查找得到该移动终端用户原接入点的地址；由无线网关根据接入移动终端用户列表中存储的信息，向原AP发出切换通知。切换通知中，包含移动终端用户标识和新AP的地址。原AP接到切换通知后，将缓存的属于该移动终端用户的业务数据发送给新AP。为保持业务的连续性，原AP还应该将该移动终端用户的加密密钥以及其他的状态信息传送给新AP。这些信息可以直接发送给新AP，也可以通过无线网关转发。完成这些操作以后，原AP仍然保留该移动终端用户的状态信息。无线网关接着向下级交换设备发出切换控制报文，控制交换设备修改路由信息，将发送给该移动终端用户的业务数据切换到新AP上来。无线网关同时通知新AP，允许该移动终端用户接入而无需对该移动终端用户认证，并将接入移动终端用户列表中的移动终端用户相关信息下发给新AP。新AP完成切换以后，无线网关更新接入移动终端用户列表中该移动终端用户的信息，并通知原AP断开与该移动终端用户的连接，将状态信息删除。原AP在切换成功之前一直保持该移动终端用户的状态信息，可以保证如果切换失败，能恢复原来状态，从而避免状态丢失。而无线网关在切换成功以后才更新接入移动终端用户列表也是出于同样的考虑。The present invention requires the cooperation of the AP and the wireless gateway or a dedicated switching control server to complete. The whole switching process is controlled by the wireless gateway. Whenever a new mobile terminal user establishes a connection with the AP, after passing the access authentication, the wireless gateway stores the mobile terminal user identification, such as the terminal address, the connection AP address and related information, into the access mobile terminal user list. The relevant information includes some information required to maintain service continuity of the mobile terminal user, such as Qos information. After the mobile terminal user goes offline, the information is deleted. While maintaining the connection with the current AP, the user measures the signal strength and quality of other APs. The user decides whether to switch and which AP to switch to according to the measured value. When the user switches to a new AP and establishes a connection with the new AP, the AP first reports the user ID of the mobile terminal to the wireless gateway, and the wireless gateway searches the mobile terminal user list to obtain the address of the original access point of the mobile terminal user; The wireless gateway sends a handover notification to the original AP according to the information stored in the access mobile terminal user list. The handover notification includes the user identifier of the mobile terminal and the address of the new AP. After receiving the switching notification, the original AP sends the cached service data belonging to the mobile terminal user to the new AP. In order to maintain the continuity of the business, the original AP should also transmit the mobile terminal user's encryption key and other state information to the new AP. This information can be sent directly to the new AP, or forwarded through the wireless gateway. After completing these operations, the original AP still retains the status information of the mobile terminal user. The wireless gateway then sends a handover control message to the lower-level switching equipment, controls the switching equipment to modify the routing information, and switches the service data sent to the mobile terminal user to the new AP. At the same time, the wireless gateway notifies the new AP to allow the mobile terminal user to access without authenticating the mobile terminal user, and sends the relevant information of the mobile terminal user in the access mobile terminal user list to the new AP. After the new AP completes the handover, the wireless gateway updates the information of the mobile terminal user in the access mobile terminal user list, and notifies the original AP to disconnect from the mobile terminal user, and deletes the state information. The original AP keeps the state information of the mobile terminal user until the handover is successful, which can ensure that if the handover fails, the original state can be restored, thereby avoiding state loss. It is also out of the same consideration that the wireless gateway updates the access mobile terminal user list after the handover is successful.

当移动终端用户主动下线时，AP不必保留该移动终端用户状态信息，并通知无线网关应立即将该移动终端用户的相关信息从列表中删除。但如果移动终端用户与AP之间的连接断开，而没有主动下线，有可能是移动终端用户移出覆盖范围所造成。因此，AP应该在一定时间范围内，缓存该移动终端用户的业务数据同时保持状态信息，以便完成切换操作。When the mobile terminal user actively goes offline, the AP does not need to keep the status information of the mobile terminal user, and notifies the wireless gateway that the relevant information of the mobile terminal user should be deleted from the list immediately. However, if the connection between the mobile terminal user and the AP is disconnected without actively going offline, it may be caused by the mobile terminal user moving out of the coverage area. Therefore, the AP should cache the service data of the mobile terminal user and keep the status information within a certain time range, so as to complete the handover operation.

下面结合附图2及具体实施例对本发明再作进一步详细的说明。The present invention will be further described in detail below in conjunction with accompanying drawing 2 and specific embodiments.

设移动终端用户A的移动终端MT1和AP1建立连接后，无线网关AS用MAC地址Uaddress1来标识该移动终端用户，并存储AP1的地址Aaddress1。移动终端在保持和AP1连接的同时，测量其他AP的信号强度和质量。发现AP2的信号质量更好，决定切换到AP2。用户向AP2发出连接请求(消息1)。AP2上报MT1地址Uaddress1(消息2)，AS收到该信息后，向AP1发出切换通知(消息3)。AP1接着向AP2发送MT1的缓存数据和状态信息(消息6)。AS同时下发路由转发更新控制报文(消息4)，并通知AP2 MT1为切换移动终端用户(消息5)。AP2接入MT1，收到AS的测试报文以后，回复切换成功信息(消息7)。AS收到该消息以后，存储AP2的地址Aaddress2，并通知AP1删除MT1状态信息(消息8)。Assume that after the mobile terminal MT1 of the mobile terminal user A establishes a connection with AP1, the wireless gateway AS uses the MAC address Uaddress1 to identify the mobile terminal user, and stores the address Aaddress1 of AP1. While maintaining the connection with AP1, the mobile terminal measures the signal strength and quality of other APs. Found that the signal quality of AP2 is better, decided to switch to AP2. The user sends a connection request to AP2 (message 1). AP2 reports the address Uaddress1 of MT1 (message 2), and after receiving the information, the AS sends a switching notification to AP1 (message 3). AP1 then sends MT1's cached data and status information to AP2 (message 6). At the same time, the AS issues a route forwarding update control message (message 4), and notifies AP2 and MT1 to switch the mobile terminal user (message 5). AP2 accesses MT1, and after receiving the test message from AS, it replies with a handover success message (message 7). After receiving the message, the AS stores the address Aaddress2 of AP2, and notifies AP1 to delete the state information of MT1 (message 8).

本发明的优点是明显的：Advantage of the present invention is obvious:

1)由于切换的控制由无线网关完成，AP处理任务相对简单，降低成本；1) Since the handover control is completed by the wireless gateway, the AP processing task is relatively simple and the cost is reduced;

2)无线网关存储切换状态数据，即使切换过程出现错误，系统能简单地恢复到原有状态，容错能力强；2) The wireless gateway stores the switch state data, even if there is an error in the switch process, the system can simply restore to the original state, and the fault tolerance is strong;

3)无线网关存储移动终端用户Qos数据，并在切换过程中下发到新的AP，可以实现保证Qos的切换；3) The wireless gateway stores the Qos data of the mobile terminal user and sends it to the new AP during the handover process, which can realize the handover with guaranteed Qos;

4)切换时，原AP的地址信息不由移动终端用户提供，而由无线网关提供，避免了移动终端用户提供错误信息而造成的切换失败；4) When switching, the address information of the original AP is not provided by the mobile terminal user, but by the wireless gateway, which avoids the handover failure caused by the wrong information provided by the mobile terminal user;

5)无线网关可以对AP进行认证，保证了切换过程的安全。5) The wireless gateway can authenticate the AP, which ensures the safety of the switching process.

6)切换测量和判决都有用户来完成，减少了AP的工作量，降低了AP的复杂度。6) The handover measurement and decision are both completed by the user, which reduces the workload of the AP and reduces the complexity of the AP.

Claims (10)

1, the method that portable terminal switches between access point in a kind of WLAN (wireless local area network) is characterized in that, may further comprise the steps:

1) mobile phone users is when keeping and the current access point is connected, and which new access point the signal strength signal intensity and the quality of other access points of measurement determine whether to switch and switch to by the user according to measured value then earlier;

2) mobile phone users communicates with the new access point of selecting and is connected;

3) after mobile phone users and new access point established a communications link, access point reported radio network gateway with the mobile phone users sign;

4) radio network gateway is searched and is inserted the mobile phone users tabulation, obtains the address of the former access point of this mobile phone users;

5) radio network gateway sends switching notice according to the access point address of storage in the tabulation to former access point;

6) data cached, state information with this mobile phone users after former access point has notice directly are sent to new access point;

7) this mobile phone users of radio network gateway notice new access point is the switching mobile phone users simultaneously, and the relevant information of this mobile phone users is sent to this new access point;

8) after new access point has notice, insert this mobile phone users; After new access point is judged handover success, send out confirmation to radio network gateway;

9) radio network gateway is received after the handover success acknowledge message, upgrades the access point address of inserting in the mobile phone users tabulation, notifies former access point to delete this mobile phone users state information.

2, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1, it is characterized in that in the described access point handoff procedure, the recipient of information can confirm the interactive information of receiving, after affirmation, begin next step action again; If acknowledge message is overtime, then return to original state.

3, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1 is characterized in that, comprises mobile phone users terminal address and new access point address in the notice described in the step 5).

4, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1 is characterized in that, the described former access point of step 6) transmits data cached, the state information of this mobile phone users and can be transmitted by radio network gateway.

5, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1 is characterized in that, the state information described in the step 6) comprises encryption key.

6, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1 is characterized in that, the relevant information described in the step 7) comprises mobile phone users quality requirement information.

7, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1, it is characterized in that, the step 7) radio network gateway can issue the control message when relevant information of this mobile phone users is sent to new access point, and the notice switching equipment is revised the forwarding route corresponding to this address.

8, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 7 is characterized in that, described can be destination address with the mobile phone users address for the access control success, sends out test packet.

9, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1, it is characterized in that, judgement described in the step 8) switches whether successful method is: send test packet by radio network gateway, access point then can be confirmed handover success after receiving test packet.

10, the method that portable terminal switches between access point in the WLAN (wireless local area network) according to claim 1 is characterized in that, described radio network gateway can authenticate former access point and new access point, and interactive information is encrypted.