Background of the invention
A radiotelephone, such as but not limited to a radiotelephone that communicates using Code Division Multiple Access (CDMA) spread spectrum modulation techniques, may be used to provide one-to-many communication capabilities (also referred to as "dispatch" or "webcast"). An example of such a service is the QChat service of the assignee of the present application, which is disclosed in the following patent application serial numbers: 09/518,622 filed on 3/2000, 09/518,776 filed on 3/2000, and 09/518,985 filed on 3/2000, all of which are incorporated herein by reference. Using the QChat service, the user of the CDMA phone can press a button on the phone to automatically invoke the aggregate amount of private, half-duplex network conversations with one or more other CDMA phone users on the network. "half-duplex" means that there is only one speaker at a time when the button is held down. When the button is released, other speakers in the network can press their talk button to talk to other phones.
The above services are based on sending voice packets encapsulated within standard Internet Protocol (IP) based protocols including UDP, ID, PPP, RTP, and RLP, which are designed to carry non-voice data (i.e., computer data) in a CDMA data service. In data services, a wireless telephone essentially acts as a data conduit to a computer that is plugged into the telephone, as opposed to voice services. In any case, it will be appreciated that the one-to-many communication capability of QChat is implemented using an IP-based service originally designed to communicate computer data.
In the field of one-to-many voice services addressed by the present invention, an element within the CDMA infrastructure, called the communications manager, arbitrates the privileges of speakers and listeners and processes IP packets carrying voice data by copying the voice packets and sending them to the IP addresses of other wireless telephones participating in the network. While QChat is an effective one-to-many communication service, the present invention recognizes that the latency and voice quality of the service can be improved.
In particular, IP-related protocols improve over-the-air reliability by introducing certain communication overhead that increases latency (communication delay), which is generally not much if there are imperfections in sending computer data, but which affects the ability of the phone to send voice data. More specifically, since the overhead of a single IP-based data protocol unit exceeds the capacity of a single CDMA air frame, the IP-based data protocol overhead must be compensated for by aggregating multiple voice frames into a single IP-based data protocol unit, resulting in increased latency for voice transmissions. Furthermore, in order to keep the increased latency to a level that can be tolerated by the user, the size of the voice packets must be reduced by limiting the CDMA vocoder (compression element) to encode data at a rate other than the peak rate. This adversely affects the speech quality.
Further, the requirement that QChat services use IP requires voice frame encapsulation within IP-based protocols and places higher processing requirements on the wireless phone. For example, a wireless telephone must implement an IP-based data protocol unit, the frequency of which is dictated by the number of voice frames aggregated within the unit. Having learned the above key phenomena, the present invention provides the solution disclosed herein.
Description of The Preferred Embodiment
Referring initially to fig. 1, a system is shown, generally designated 10, for enabling one-to-many communication between a transmitting wireless communication device 12 and a plurality of group member telephones 13 through an IP-enabled telephone infrastructure 14, wherein the transmitting wireless communication device 12 does not support Voice Over Internet Protocol (VOIP), and the plurality of group member telephones 13 also do not support VOIP as well. "VOIP not supported" or "IP not supported" means that the devices 12, 13 either do not have IP or VOIP capability or they have such capability but communicate with the infrastructure 14 using standard over-the-air (OTA) voice protocols for improved voice performance, such as: CDMA or WCDMA or other wireless protocol spreading schemes such as but not limited to TDMA, UMTS, TD-SCDMA, etc. In one non-limiting embodiment, the devices 12, 13 are mobile phones manufactured by Kyocera, Samsung, or other manufacturers that communicate with the infrastructure 14 using Code Division Multiple Access (CDMA) principles and CDMA over-the-air (OTA) communication air interface protocols, which are defined as follows but are not limited to: IS-95A, IS-95B, UCDMA, IS-2000 and others.
For example, to generalize the above, a wireless communication system to which the present invention can be applied includes: personal Communication Services (PCS) and cellular systems, such as the analog Advanced Mobile Phone System (AMPS) and the following digital systems: CDMA, Time Division Multiple Access (TDMA), and hybrid systems using both TDMA and CDMA technologies. CDMA cellular systems are described in the telecommunications industry association/electronic industries association (TIA/EIA) standard IS-95. A combined AMPS and CDMA system IS described in TIA/EIA Standard IS-98. Other communication systems are described in International Mobile Telecommunications System 2000/Universal Mobile Telecommunications System (IMT-2000/UM), including Wideband CDMA (WCDMA), cdma2000 (such as the cdma 20001 x or 3x standard), or TD-SCDMA.
The present invention applies to any wireless communication device 12; for purposes of illustration, it is assumed that device 12 is a telephone. In general, wireless communication devices to which the present invention may be applied may include, but are not limited to: a wireless handset or telephone, a cellular telephone, a data transceiver, or a paging and addressing receiver, and may be hand-held or portable while installed in a vehicle (including cars, trucks, boats, planes, trains). Although wireless communication devices are generally considered to be mobile, it will be appreciated that the present invention may be applied to "fixed" units in some implementations. Likewise, the present invention applies to data modules or modems used to transfer voice and/or data information, including digitized video information, and may communicate with other devices using wired or wireless links. Further, commands may be used to cause modems or modules to work in a predetermined coordinated or correlated manner to transfer information over multiple communication channels. Wireless communication devices are also sometimes referred to as user terminals, mobile stations, mobile units, subscriber units, mobile radios or radiotelephones, wireless units, or simply as "users" and "mobile telephones" in some communication systems.
As shown in fig. 1, the wireless telephone 12 communicates with at least a first infrastructure element 16 using one or more of the systems described above, which accesses a logic module to execute the logic of the present invention. The first element 16 is preferably a base station (BTS), but it may also be implemented with a Base Station Controller (BSC), a Mobile Switching Center (MSC), a gateway to a satellite system, or other infrastructure element. In any case, the first element 16 supports not only the necessary protocols and systems to communicate with the wireless device 12, but also IP (including an attached protocol or IP (protocol) stack), so the element 16 communicates with the infrastructure 14.
Infrastructure 14 may include a BSC or other BTS using IP. Preferably, the BTS performs conventional BSC functions, thereby eliminating the need to provide a BSC. It will be appreciated that although fig. 1 shows a single BTS16 in communication with the telephones 12, 13, each telephone 12, 13 may communicate through the infrastructure 14 via separate individual BTSs.
Thus, the infrastructure element 16 communicates with the wireless telephones 12, 13 using OTA protocols, but communicates internally with the infrastructure 14 using IP, thereby alleviating the task of the wireless telephones 12, 13 having to support IP or the accompanying voice over internet protocol suite, or any processing, resource usage, etc. associated with implementing IP. Also, by using IP within infrastructure 14 and OTA protocol between phones 12, 13 and their respective BTSs 16, the advantages of using IP within infrastructure 14 can be realized while retaining the advantages of OTA protocol in the wireless communication of phones 12, 13 to maximize the over-the-air capacity of system 10. Thus, the infrastructure element (BTS)16 can be considered as a virtual IP end, while the actual communication end is the phone 12, 13.
As contemplated herein, the transmitting radiotelephone 12 may communicate with the communication manager 20 using the infrastructure 14. In one non-limiting embodiment, communication between infrastructure 14 and communication manager 20 occurs over a link 22, such as, but not limited to, the Internet. The communication manager 20 is a suitable device for managing one-to-many communications in accordance with principles known in the art. To do so, the communication manager 20 accesses a group database 24, which database 24 contains the identity and membership of the customized group of telephones 12, 13. In one non-limiting embodiment, the communication manager 20 may be a QChat communication manager.
Having reviewed the present structural overview, it can be appreciated that the present logic executes on the structure shown in FIG. 1 in accordance with the following flow chart. The flow charts herein illustrate the logical structures of the present invention incorporated in computer program software. Those skilled in the art will appreciate that the flow charts illustrate the structures of logic elements, such as computer program code elements or electronic logic circuits, that function according to this invention. It is to be understood that the present invention, in its most basic embodiment, may be implemented by a machine element that provides logic elements in a form that instructs a digital processing apparatus (i.e., a computer, controller, processor, etc.) to perform a sequence of function steps corresponding to those illustrated.
In other words, logic may be embodied in a computer program that is executed by a processor, such as within infrastructure element 16 and/or communication manager 20, as a series of computer or control element executable instructions. These instructions may reside, for example, in RAM or a hard drive or optical drive, or the instructions may be stored on magnetic tape, electronic read-only memory, or other suitable data storage device that can be dynamically changed or updated.
Referring now to FIG. 2, the logic of the present invention can be seen. Beginning in block 26, the user of the telephone 12 may press a hardware or software implemented "send" button 28 on the telephone 12. Button 28 may be any suitable phone button used for one-to-many communications, such as, to name a non-limiting example: is a "send" button. It will be appreciated that when one-to-many service enables telephones 12 to belong to multiple groups, the user may first select the desired group according to one-to-many communication principles known in the art.
In any case, when the send button is pressed, a "send" signal is sent to the element 16 at block 30. In the case where telephone 12 supports IP for data services, pressing the send button prompts telephone 12 to issue a signal to the infrastructure to ensure that voice communications are carried out using OTA protocols that are not encapsulated within IP, as described below.
The transmission signal may be any suitable signal for signaling a one-to-many session to be entered. For example, the transmitted signal may be a CDMA signaling message indicating a request for one-to-many communication and identifying the transmitting telephone 12 and the one-to-many group to be included, as indicated by the user properly operating the control keys of the telephone 12.
In block 31, the transmitted signal is received by the first element 16 (e.g., BTS), which in one non-limiting embodiment is converted to IP and transmitted through the infrastructure 14. In an exemplary, non-limiting embodiment, the processing in block 31 may include: receives CDMA protocol one-to-many origination messages from telephone 12 in accordance with IS-95 protocol and then, in response, substantially converts the one-to-many origination messages to IP by sending IP-based Session Initiation Protocol (SIP) messages from first element 16 to other appropriate elements such as communications manager 20 in accordance with principles known in the art.
Next, in block 32, the communication manager 20 receives the one-to-many request and establishes a priority of the transmitting telephone 12 to speak. Likewise, the communication manager 20 accesses the database 24 to identify the individual recipient telephones 13 within the group, as indicated by the information in the signaling message. The SIP messages described above are then used to establish a communication channel within the infrastructure 14 to the group members to establish communication with the intended recipient phone 13 via their respective IP ends, for example via the first element 16 (e.g. BTS) in the simplified embodiment shown in figure 1 or via another BTS.
The user then speaks into the telephone 12, at which point OTA voice packets, such as CDMA voice packets, are generated and transmitted without encapsulating them in IP, block 34. In block 36, OTA voice packets are received at the first element 16, i.e., at the IP end, and converted to IP. To make this transformation, the contents of the OTA voice packets are rearranged appropriately to conform to the IP packet requirements. In general, since OTA voice packets are smaller than IP packets and usually smaller than the header of IP packets, it is possible to combine several OTA packets into a single IP packet, although this may not be necessary in latency-intensive applications. One benefit of encapsulation within IP at the infrastructure is that bandwidth usage is less of an issue and individual voice frames may each be encapsulated in IP. In addition, well-known IP header compression techniques may be employed to reduce the size of the header.
At block 38, the information within the IP is sent to communication manager 20 via infrastructure 14. Moving to block 40, the communication manager 20 duplicates the packets as needed, one copy for each recipient phone 13 in the group, and sends the duplicated IP packets to the IP address of each corresponding recipient phone 13 in the group. The IP packets are then routed through the infrastructure 14 to the appropriate IP end (e.g., BTS) in communication with the recipient phone 13.
At the IP end of the respective recipient telephone 13 (e.g., BTS), the IP packets representing the voice information from the transmitting telephone 12 are converted to OTA packets in block 42. In the simplified embodiment shown in fig. 1, the first element 16 acts as an IP end for both the transmitting telephone 12 and the recipient telephone 13. In block 44, the OTA packet is sent to the recipient phone 13. The IP-to-OTA protocol conversion is the inverse process of converting OTA packets to IP packets, i.e., each IP packet can be appropriately divided into a set of smaller OTA packets to conform to the OTA protocol used by the recipient phone 13.
The communication manager 20 also arbitrates between the telephones 12, 13 for establishing a half-duplex session, i.e. a communication session in which only a single telephone 12, 13 is allowed to transmit voice packets at a time. Such arbitration may be carried out according to means known in the art. For example, when the user of the transmitting telephone 12 holds down the send button 28, the other telephones 13 within the group will not be allowed to send OTA packets until the user releases the button. Then, the user of one of the recipient telephones 13 can press and hold their send button to speak, in accordance with the principles described above.
While the particular EFFICIENT CDMA ONE-TO-MANY SERVICE (effectively CDMA ONE-TO-many service) illustrated and described in detail herein is fully capable of attaining the above-described objects of the invention, it is TO be understood that it is the preferred embodiment of the present invention and is intended TO represent the only major problem underlying the broad inventive concept, that the scope of the present invention fully encompasses other embodiments which may become obvious TO those skilled in the art, and that the scope of the present invention is accordingly TO be limited by nothing other than the appended claims, in which reference TO an element in the singular is not intended TO mean "ONE and only ONE" unless specifically so stated, but rather "ONE or more". Structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the following claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. None of the claim elements herein are to be understood as being in accordance with the provisions of 35 u.s.c. § 114 sixth paragraph, unless the element is specifically designated by the phrase "means for.