Method and apparatus for a talkgroup call in a wireless communication system

[0001] [Cross-reference of related co-pending applications] The present invention is entitled "Methods and Devices for Call Group Calls in Wireless Communication Systems", the application number is 09/534384 (agent case number CE08344R), and the application is owned by the same assignee on the same day. is connected with. [Field of invention] The present invention generally relates to radio code division multiple access systems, especially methods and devices for call group calls in such systems. [Background of invention] Two-way wireless communication systems incorporating group dispatch services are known in the art. Group delivery services generally provide communication within a calling group. A calling group is a collection of logically cohesive subscriber devices (eg, automotive and / or portable radios) capable of engaging in group-wide communication. In normal call group communication, a single subscriber device in the call group transmits voice information, which voice information is received by the fixed infrastructure and retransmitted to other subscriber devices in the call group. In general, such systems utilize frequency division multiple access (FDMA) and / or time division multiple access (TDMA) methods to receive and broadcast transmission content. In an FDMA system, one uplink is usually paired with one downlink, and that uplink is only available to one subscriber device at a time. Similarly, in a TDMA system, uplink and downlink time slots are paired so that only one subscriber device can send a retransmission credit uplink message at a time. [0002] While these systems provide informative group communications, they force some tight control over communications so that only one subscriber at a time "owns" the call. That is, since only one subscriber device can transmit at a time, more natural group-style communication with a large number of speakers and a large number of listeners at the same time is not possible. Many prioritization methods exist today, allowing high-priority users or users with high-priority traffic (eg, emergency calls) to be declared as the owner of a call group, but communication is still a single speaker. / Are bound by the format of a large number of listeners. [0003] Current telephone services provide conference calls that allow a large number of speakers and a large number of listeners to join the call at the same time. It would be possible to extend conference calls to current wireless systems by assigning each uplink or time slot to each potential speaker and each downlink or time slot to potential listeners. In addition, it would be possible to assign each fully dual channel (uplink and downlink resources) to each subscriber device in the calling group. While these methods may work, they are extremely inefficient in terms of resource utilization. For example, forming a calling group that includes up to 100 subscriber devices is not unusual in a publicly secure organization. Obviously, the communication resources required to establish a group conference call using each uplink and / or downlink resource for up to 100 subscriber devices would exceed the capacity of most communication systems. .. One approach to the above problem is "METHOD AND APPARATUS FOR A TALKGROUP CALL IN A WIRELESS CDMA". Grube et al., Titled "SYSTEM", assigned to the assignee of the present invention and also used as a reference in this application. Granted by US Pat. No. 6,005,848. According to Grube et al., Partial call groups in a call group are assigned at least one uplink code, and the entire call group is assigned one downlink code. Members of the partial call group can simultaneously transmit voice information using the uplink code. The voice information of the speaker is added and broadcasted to all users in the call group. The method described above can provide a more natural conversation between users, but the drawback of this method is that the person actually speaking causes them to broadcast their voice. , The voice can be annoying to the speaker. [0004] Therefore, a member of a call group in a wireless communication system that allows a large number of users to broadcast to the call group at the same time, but prevents the busy person from hearing their voice broadcast. Double communication between them is desired. [Explanation of preferred examples] In general, the present invention provides dual communication in a calling group where the speaker's voice is not broadcast to the speaker. At least one uplink code is assigned to a partial call group of subscriber devices that forms part of the call group. A downlink code is assigned to the call group. Members of the partial call group simultaneously transmit voice information using at least one uplink code, and the voice information is added and retransmitted to the call group using the downlink code. The audio information is added so that each speaker receives the added audio information excluding the audio content of the individual subscriber. Subscriber devices (partial listening groups) that do not belong to the partial call group but belong to the call group are allowed to transmit voice information only after requesting and receiving an additional uplink code. [0005] The present invention includes methods for a fixed infrastructure for establishing call group calls. This method consists of receiving a request for a call group call from the first subscriber device among the multiple subscriber devices, the request being the identity of the first subscriber device and the call group. Consists of identity information. Based on the identity information of the call group, the call group of the subscriber device consisting of at least two subscriber devices among the plurality of subscriber devices is determined. The partial call group of the subscriber device of the call group is determined based on the identity information of the first subscriber device. A downlink code is assigned to the subscribers in the partial listening group, and a plurality of downlink codes are assigned to the subscribers in the partial call group in a one-to-one format. Then, at least one uplink code is assigned to the partial call group in a one-to-one format. [0006] The present invention also includes methods for fixed infrastructure to establish call groups. This method consists of receiving uplink voice data from a plurality of subscriber devices in a call group, and the uplink voice data consists of voice data from the first subscriber. Upstream audio data is added to generate the first added audio data. The voice data of the first subscriber is removed from the added voice data to generate the second added voice data. The first added audio data is transmitted to the subscribers in the partial listening group, and the second added audio data is transmitted to the first subscriber. [0007] The present invention further comprises a stage of receiving uplink voice data from a plurality of subscriber devices in a call group, and the uplink voice data comprises voice data from a first subscriber. The first added voice data is transmitted to the subscribers in the call group who are not actually talking, and the first added voice data consists of the sum of a plurality of subscribers who are actually transmitting the upstream voice. .. Then, the second added voice data is transmitted to the subscribers in the call group who are actually having a conversation, and the second added voice data is composed of the first added data excluding the voice component of each speaker. [0008] The present invention further includes a wireless communication system consisting of a receiver that has an individual subscriber audio signal and a plurality of other uplink audio signals as inputs and outputs an audio signal suitable for addition. This receiver further has an audio signal suitable for addition as an input, and is composed of an addition circuit that outputs an addition audio signal, and the addition audio signal is an audio signal of each subscriber from the sum of a plurality of uplink audio signals. Consists of subtracting. The receiver comprises an additional audio signal as an input and a transmission circuit that outputs a coded audio signal suitable for each subscriber to receive. [0009] Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 5. FIG. 1 is a block diagram of the wireless communication system 100 according to the present invention. In a preferred embodiment of the present invention, the communication system 100 is a cdma2000 International Telecommunication Union-Radio Communication (ITU-R) radiotransmission technology (RTT:). Radio Transmission Technology) Use the next-generation CDMA mechanism as described in the candidate proposal documents. However, in other embodiments, communication system 100 can utilize other analog or digital cellular communication system protocols, which are next-generation global systems for mobile communications. As described in the GSM) protocol, or "Personal Station-Base Station Compatibility Requirements for 1.8 to 2.0 GHz Code Division Multiple Access (CDMA) Personal Communication Systems" (American National Standards Institute (ANSI) J-STD-008). Something like, but not limited to, CDMA system protocols. [0010] The wireless communication system 100 comprises a plurality of subscriber devices 104-109 organized into at least one call group in wireless communication utilizing the fixed infrastructure 103. The call group 101 further comprises a partial call group 102 and a partial listening group 130. As illustrated, the subscriber device designated by reference number 104-106 is included in call group 101 and partial call group 102, and the subscriber device designated by reference number 107-109 is included in the partial listening group. In a preferred embodiment, each subscriber device 104-109 is structurally capable of dual communication. However, as described in detail below, only subscriber devices included in the partial call group are logically allowed to engage in dual communications with respect to the call group 101. [0011] As is known in CDMA systems, communication channels 117-125 are efficiently supplied using spread codes. As described in detail below, the downlink code is used to efficiently supply the downlink communication channels 117-122 to each subscriber of the call group 101. Further, the uplink code (three are exemplified in FIG. 1) is used to efficiently supply the uplink communication channels 123-125 to each subscriber device of the partial call group 102. [0012] The fixed infrastructure 103 consists of the elements normally required for communication in the wireless system 100 (following a packet-based CDMA mechanism in a preferred embodiment). In particular, the fixed infrastructure 103 consists of a switch 110 that communicates with the controller 111, which communicates with the base station transceiver system (BTS) 112-113. Switches 110 (also referred to as mobile exchange centers or MSCs), controllers (also referred to as base station controllers or BSCs) and BTS 112-113 are well known in the art. In practice, the switch 110 can generally communicate with one or more controllers and also with other devices not shown. For simplicity, Fixed Infrastructure 103 has been simplified as shown in Figure 1. The fixed infrastructure 103 can also selectively include a delivery (dispatch) controller 114 that communicates with the BTS 112-113. The appropriate delivery controller 114 is Motorola, A distribution application processor used in the "iDEN" wireless communication system manufactured by Inc. The management of group call processing is preferably handled by controller 111 or, if used, by distribution controller 114. In addition, the functionality of group calls can be distributed within the fixed infrastructure 103, as described below. [0013] FIG. 2 is a flowchart showing the method used in the fixed infrastructure 103. The method described in FIG. 2 is generally performed by the fixed infrastructure 103, but this method is preferably performed by the controller 111 or, if used, by the distribution processor 114. In addition, the roles shown in FIG. 2 can be distributed through the fixed infrastructure 103. Generally, the method shown in Figure 2 is performed as a storage software routine executed by the platform on which the software is stored. [0014] In step 202, the fixed infrastructure 103 receives a call group call request from the subscriber device of call group 101. The requesting subscriber device may be one of the subscriber devices 104-106 included in the partial call group 102, or one of the subscriber devices 107-109 that is not a member of the partial call group 102. In any case, the request includes the identity information of the requesting subscriber device and the identity information of the calling group for which communication is to be established. In step 204, the fixed infrastructure 103 utilizes the table and the identity information of the calling group and the requesting subscriber device to allow which subscriber device in the calling group 101 to double-communicate the calling group call. Find out if it is about to be established as a participant or subscriber device included in the partial call group 102. The table used for this purpose is further described in connection with FIG. [0015] Figure 3 shows Table 300 used by Fixed Infrastructure 103 when establishing a call group call. Table 300 comprises a series of entries that associate the call group identity information 301 with the requesting subscriber device identity 302 and the partial call group 303 corresponding to each requesting subscriber device. One advantage of this configuration is that various forms of partial call groups are dynamically provided by changing the entries in Table 300. With reference to the example shown in FIG. 3, the calling group distinguished as TG001 includes subscriber devices distinguished by SU001, SU002, SU003, SU004, SU008 and SU009. If the subscriber device SU003 requests a call group call, SU001, SU002, SU003, SU004, SU008 and SU009 are included in that call group, and the subscriber devices SU001 and SU008 are members of the dual communication partial call group. Established as. Also, if any one of the subscribers SU002, SU004 or SU009 requests a call group call, SU001, SU002, SU003, SU004, SU008 and SU009 are included in that call group and only the subscriber device SU001 is 2 Established as a member of a heavy-duty partial call group. [0016] The data entered in the partial call group entry 303 for dual communications can be entered by the system administration or automatically as a dynamic function of various events. is there. One technique for achieving a dynamic update of subgroup entry 303 is to sequentially store the identity information of the subscriber device that has recently engaged in communication with the requesting subscriber device. That is, when one-to-one communication is established with a given device, the partial call group entry is updated to include the identity of the subscriber device that participated in such one-to-one communication. It is also possible to add a subscriber device (discussed in detail later) that is required to be added to a call group call initiated by the requesting device to the appropriate subgroup entry. Such a "recent" time frame (time window) is an optional design matter, such as an absolute time (eg, only subscriber devices that communicated within the last X minutes) or a sequence (eg, communication). It is possible to base on only the last X subscriber devices that did. Another method is to update the partial call group entry 303 based on the relative priority of the subscriber device within the call group. For any given subscriber device, a partial call group consists of subscriber devices in a call group that have at least as high a priority as a given device. As the priority with respect to the subscriber device changes, the partial call group entry 303 can be updated accordingly. Yet another method is to update the partial call group entry 303 based on the position of the subscriber device relative to each other. As a given subscriber device updates its current location, the subcall group corresponding to that subscriber device is updated and the subscriber device within a given distance (eg, 1 mile) from that given subscriber device. Only included. It will be clear that other methods are possible for those with ordinary knowledge in the art. In addition, other embodiments that lead to results similar to Table 300 are also available. [0017] Subscribers can dynamically switch between partial calling groups and partial listening groups. If a subscriber requires to be part of a partial listening group, new up and down channels will be assigned to this subscriber. The subscriber then switches from the partial listening group to the partial calling group. If, in order to save RF resources, only a subscriber in the partial calling group is required to listen, the subscriber's uplink and downlink channels are released and the downlink channel in the partial listening group is given to the subscriber. Assigned. After that, the subscriber switches from the partial call group to the partial listening group. [0018] Returning to FIG. 2, the partial listening group 130 and the partial calling group 102 are determined, and the fixed infrastructure 103 assigns a plurality of downlink and uplink codes to the partial listening group and the partial calling group, respectively. In a preferred embodiment of the present invention, a single multicast downlink channel is assigned to the users in the partial listening group 130. However, each user in the partial call group 102 is assigned one unique channel for downlink transmission. If there is only one subscriber device / speaker in the partial call group, it is not necessary to assign a downlink channel to this subscriber device / speaker. For this purpose, the fixed infrastructure 103 determines in step 206 the plurality of downlink codes to be used for the call group 101 and at least one downlink code to be used for the partial call group 102. The fixed infrastructure 103 can determine a single downlink code used by the partial call group 102, and preferably an individual downlink code assigned to each member of the partial call group 102. The downlink code is used to generate downlink channels 117-122 for each subscriber device in call group 101 (also known as downlink or forward channel). At least one uplink channel (also known as an uplink or reverse channel) is used for members of partial call group 102. The downlink code and at least one uplink code are notified to the call group 101 in step 208. This notification is made using a control channel based on a PN code known to each subscriber device, and this control channel is monitored by the subscriber device. [0019] In a preferred embodiment of the present invention, when the maximum number of subscribers of a partial call group is 1, the group call is the same as the iDEN delivery call. It requires only one up channel and one down channel. If the maximum number of subscribers in a partial call group is equal to that number in the call group, then the group call is similar to a full double conference call. It requires N up channels and N down channels, where N is the number of subscribers in the calling group. However, if the maximum number of subscribers M in a partial call group is between 1 and N, the group call is identified as an M-master dispatch call. This design requires M up channels and M + 1 down channels. [0020] Once the code assignment is made, only the subscriber devices included in the partial call group 102 can perform uplink transmission for the call group call. Therefore, in step 210, the distribution controller 114 receives a stream of voice information from one or more subscribers in the partial call group 102. The audio stream is fed to the distribution controller via base stations 112-113. Assuming that at least two subscriber devices are assigned uplink codes within the call group 102, the stream of voice information received by the fixed infrastructure 103 is at the same time, in a format that represents normal group-style communication. arrive. Devices in the partial call group 102 that do not transmit voice at the same time transmit an idle pattern as is known in the art. In step 212, the fixed infrastructure 103 (delivery controller 114) adds a stream of audio information to generate the added audio information. Although not intended to be limited, it is possible to utilize a variety of addition techniques, including arithmetic addition in conference bridges or signal processing devices. If the stream of audio information is in an unsuitable format for addition, such as compressed digital audio, it is known in the art to convert the stream of audio information into a format that can be easily added. At least one provisional transcoder is required. Enhanced Variable Rate Codec (EVRC: When Enhanced Variable Rate Coder) is used, only two signals are combined. This is because the EVRC vocoder encodes the voices of up to two people. If two or more audios are combined, the distribution information exceeds the EVRC vocoder limit. Therefore, when an EVRC vocoder is used, only the top two highest energy audio signals are added. In a preferred embodiment of the invention, a determination is made as to where the resulting added signal should be transmitted. If the resulting signal is to be transmitted to the current speaker in subgroup 102, the resulting added voice will have that speaker's voice removed from the added signal ( Step 213). If the resulting signal is transmitted to a subscriber who is not currently speaking, there is no audio signal removed from the addition signal in step 213. [0021] [0021] Regardless of the addition method used, the added voice information is transmitted by the fixed infrastructure 103 using a downlink code. Since the downlink code is used, only the subscriber device using the specific code can receive and restore the added voice information. Since the added voice information represents a large number of speakers, more realistic group communication is achieved. Since each user's voice is removed from the downlink signal, the user's voice does not need to be broadcast to them. [0022] According to the present invention, a subscriber device that is not currently a member of the partial call group 102, i.e., unable to transmit voice information, needs to require the ability to transmit. At step 214, the fixed infrastructure 103 checks to see if any subscriber device in the partial listening group has transmitted the call request. The call request is transmitted on a channel (ie, control channel) based on a code other than that of the uplink code assigned to the partial call group 102. The call request includes the identity of the call group 101 and the identity of the subscriber device requesting the call. When such a request is received, the fixed infrastructure determines in step 216 an additional uplink code that is preferably different from the previously assigned uplink code. The additional uplink code is notified to the requesting device in step 208, and the process of the call group call proceeds as before except that the requesting device is added to the call as a speaker. As mentioned above, the table described in connection with FIG. 3 is a request (with an additional uplink code) in the partial call group entry used to establish the current call group call. Updated to include the device. The operation of the subscriber device to capture steps 214 and 216 will be described later in connection with FIG. [0023] If no call request was received in step 214, does fixed infrastructure 103 only require the subscribers / speakers in the partial call group to listen rather than speak in step 218? Find out if it isn't. If a subscriber / speaker in a partial-call group only requests listening, in step 220, the subscriber's uplink and downlink channels are opened and the partial-listening group's downlink channel is assigned to that subscriber. The subscriber moves from the partial calling group to the partial listening group. [0024] Fixed infrastructure 103 determines whether the call group call has ended (step 222). It will be appreciated that various techniques can be employed to detect the termination of a call group call. For example, a time-out timer can be utilized after all devices have finished transmitting idle patterns or voice information. It is also possible to detect that all subscriber devices in the partial call group 102 have become quiet (dekey). In any case, upon termination of the call group call, the fixed infrastructure 103 unassigns the downlink and uplink codes in step 224. Similar to step 208, downlink and uplink code deallocation can be performed on the control access channel using known PN codes. [0025] The operation according to the present invention will be further described with reference to FIG. In FIG. 4, fixed infrastructure 103 adds receiver 409 to provide individual streams 410-411 of voice information based on transmission by members of partial call group 102, and adder 412 to add streams of voice information 410-411. And 415, and a transmitter 414 that transmits the added voice information 413 to the call group 101 using the downlink code 425 (indicated by the codes A, D, E). Transmission by members of partial call group 102 is based on uplink code 416-417 (indicated by "code B" and "code C"). In a preferred embodiment of the invention, the adders 412 and 415 are part of a distribution controller 114 that is external to base stations 112-113. [0026] As shown in FIG. 4, each subscriber device 104-109 has a set of common elements. In particular, the control and processing element 401, which generally consists of one or more processing units (eg, microprocessors, digital signal processing units, etc.), is coupled to memory 402. The control and processing element 401 is coupled to a transmitter 403, a receiver 404, a speaker 405, a microphone 406 and an input device 407. Each of these elements is well known in the art. Under the control of the software algorithm stored in the memory 402, the control and processing element 401 performs the required tasks with respect to the operation of the subscriber device. The receiver 404 is used to receive the downlink and / or uplink code assignments used in the call group call, and subsequently receive the downlink and / or uplink code deallocation. Further, in all the subscriber devices included in the call group 101, the added voice information 413 modulated by the downlink code 415 and received via the receiver 404 is processed and supplied to the speaker 405. In this way, the subscriber device included in the call group 101 can monitor the downlink communication corresponding to the call group call. An input device 407 consisting of a keypad, activation menu display or similar device allows the user to send a call request. In a dual communication subscriber device (ie, a member of partial call group 102), speech input via microphone 406 is processed and provided as a stream of voice information to transmitter 403 for transmission under uplink code 416-417. To. The dual communication subscriber device is a voice activation switching element so that a continuous stream of voice information (if the speech is picked up by the microphone 406) or an idle pattern (if the speech is not picked up by the microphone 406) is transmitted. It is also possible to use (VOX) 408. [0027] In the example of FIG. 4, two unique uplink codes (code B and code C) are used by the subscriber device in the partial call group 102 to transmit streams 410-411 of voice information. In reality, the uplink code (code B and / or code C) is not only used to send the uplink voice information, but also to send the power control information, and the fixed infrastructure 103 is the downlink code. Know the state of. That is, the fixed infrastructure 103 adjusts the downlink transmit power with respect to the downlink to maintain communication. In addition, some downlink codes 425-427 (codes A, D, E) are used to transmit the resulting added audio information. In practice, the downlink is not only used to transmit the additive voice information 413, but also to transmit control information such as uplink code allocation and power control information to the members of the partial call group 102. used. [0028] As mentioned above, a large number of subscriber devices that are members of the partial call group 102 can simultaneously transmit voice to the fixed infrastructure 103. In a preferred embodiment of the invention, the audio signal is received by receiver 404 and transmitted to processor 418. However, when an EVRC vocoder is used, the processor 418 transmits all the codes to the adder 412, and only the top two audio signals with the highest energy are transmitted from the processor 418 and added in the adder 412. The resulting added voice is transmitted to the second adder 415, and each voice signal is removed from the added signal 413. In a preferred embodiment of the invention, the control and processing device 418 adds its own audio signal to the adder 415 so that it is removed from the adder 413 even if its own audio signal has the highest audio energy. To transmit to. Each individual audio signal transmitted to the adder 415 is determined by where the resulting signal 419 is transmitted. For example, when a signal using a specific code (code D) is transmitted to the subscriber 104, the audio signal from the subscriber 104 is transmitted to the adder 415 and removed from the signal 413. The resulting signal (signal 419) is then spread using a specific spreading code (code D) and transmitted to the subscriber 104. The result is a signal received by subscriber 104, which is the additive signal of all simultaneous speakers (or the top two) except the signal from the uplink channel of subscriber 104. [0029] According to a preferred embodiment of the present invention, a particular speaker in subgroup 102 receives a downlink signal consisting of combined voices of all the speakers in the subgroup, but the voice from that particular speaker is It has been removed from the downlink signal. Devices 107-109 in the partial listening group receive the combined signal of all speakers with no audio removed from signal 413. This is achieved by the processing device 418 not transmitting the signal to the adder 415 when transmission to devices 107-109 is desired. [0030] As mentioned above, the subscriber device within the partial listening group can send a call request to the fixed infrastructure 103 to participate in the call group call. The operation in the subscriber device for this purpose is shown in Figure 5. In step 502, the subscriber device receives a downlink code assignment for a call group call. As mentioned above, such assignments are generally transmitted over control access channels established using known code. [0031] In step 504, the subscriber device can selectively monitor downlink communications for call group calls. This step is optional when the user of the subscriber device chooses not to monitor the call group call and the downlink communication is not available immediately after receipt of the downlink code assignment. In any case, in step 506, the subscriber device examines the need to send a call request where the request is directed to a call group call. After sending the call request to the fixed infrastructure 103 in step 508, if there is one or more speakers in the partial call group in step 510, the subscriber device will have an additional uplink code and an additional downlink code. Receive assignments from Fixed Infrastructure 103. Upon receiving the assignment, if there is one or more speakers in step 512, the subscriber device utilizes the uplink code to initiate the transmission of an additional stream of voice information, and utilizes the downlink code. It is possible to start receiving an additional stream of audio information. In this way, a given subscriber device can remain an auditor-only participant or, if desired, change state to an active participant (ie, speaker) in a calling group call. is there. [0032] FIG. 6 is a block diagram showing the operation of the wireless communication system of FIG. 1 according to another embodiment of the present invention. In another embodiment of the invention, communication system 100 utilizes a time division multiple access (TDMA) system protocol. Other examples are preferably commercially available from Motorola, Inc. [0033] [Outside 1]<img file="JP4979172B2_D0001.tif" />The system, communication system 100, will be described. Base stations 112-113 preferably consist of an "iDEN" enhanced transceiver base station (EBTS), also Motorola, Commercially available from Inc., it provides at least distribution communication services to subscriber devices 104-109. The communication device 104-109 preferably comprises a two-way radio or radiotelephone such as a Motorola iDEN mobile radio or mobile radio. [0034] In FIG. 6, fixed infrastructure 103 adds receiver 609, which provides individual streams 610-611 of voice information based on transmission by members of partial call group 102, and adder 612, which adds streams 610-611 of voice information. And a switch 615 and a transmitter 614 that transmits the voice information 613 added using the downlink channels 615 (channels A, D and E) to the call group 101. Unlike the preferred embodiment in which the CDMA system mechanism was used, in other embodiments the channel consists of a combination of specific frequency / time slots. Transmissions by members of partial call group 102 are based on uplink channels 616-617 (Channel B and Channel C). [0035] As shown in FIG. 6, each of the subscriber devices 104-109 has a set of common elements. In particular, a control and processing element 601 generally consisting of one or more processing units (eg, microprocessor, digital signal processing equipment, etc.) is coupled to memory 602. The control and processing element 601 is coupled to a transmitter 603, a receiver 604, a speaker 605, a microphone 606 and an input device 607, and time division switches 608 and 609. Each of these elements is well known in the art. Under the control of a software algorithm stored in memory 602, control and processing element 601 performs the required tasks with respect to the operation of the subscriber device. The receiver 604 is used to receive the downlink and / or uplink channel assignments used in the call group call, and subsequently receive the downlink and / or uplink channel deallocation. Further, in all the subscriber devices included in the call group 101, the added voice information 613 modulated by the downlink channel 615 and received via the receiver 604 is processed and supplied to the speaker 605. In this way, the subscriber device included in the call group 101 can monitor the downlink communication corresponding to the call group call. An input device 607 consisting of a keypad, activation menu display or similar device allows the user to send a call request. In a dual communication subscriber device (ie, a member of partial call group 102), speech input via microphone 606 is processed and provided as a stream of voice information to transmitter 603 for transmission based on uplink channels 616-617. To. The dual communication subscriber device is a voice activation switching element so that a continuous stream of voice information (if the speech is picked up by the microphone 606) or an idle pattern (if the speech is not picked up by the microphone 606) is transmitted. It is also possible to use (VOX) 608. [0036] In the example of FIG. 6, two unique uplink channels (channel B and channel C) are used by the subscriber device in the partial call group 102 to transmit streams 610-611 of voice information. In reality, the uplink channels (channel B and / or channel C) are not only used to transmit uplink voice information, but also to transmit power control information, and the fixed infrastructure 103 is the downlink code. Know the state of. That is, the fixed infrastructure 103 coordinates the downlink transmit power for the downlink to maintain communication. In addition, some downlink channels 625-627 (channels A, D, E) are used to transmit the resulting added audio information. [0037] As mentioned above, a large number of subscriber devices that are members of the partial call group 102 can simultaneously transmit voice to the fixed infrastructure 103. In a preferred embodiment of the invention, the audio signal is received by receiver 604 and transmitted to processor 618. However, when an EVRC vocoder is used, processor 618 transmits all channels to adder 612, and only the top two audio signals with the highest energy are transmitted from processor 618 and added at adder 612. The resulting added voice is transmitted to the switch 615, the added signal 613 is transmitted or not transmitted to the transmitter 614 depending on the current speaker, and the resulting signal 619 is transmitted. For example, if a signal utilizing a particular channel (channel D) is transmitted to subscriber 104, the audio signal from subscriber 104 is not transmitted to transmitter 614 due to switch 615. As a result, the signal received by the subscriber 104 has no audible component when the subscriber 104 has a conversation. [0038] According to a preferred embodiment of the present invention, a particular subscriber in subgroup 102 receives a downlink signal consisting of combined voices of all speakers in the subgroup, but the particular subscriber has a conversation. If so, the switch 615 does not pass the coupling signal 613, so that the subscriber does not receive any audible signal. Devices 107-109 in the partial listening group receive the combined signal from all speakers by a switch 615 that passes the combined signal 613. [0039] To save RF resources, transmit and receive operations utilize different time slots. For example, with respect to FIG. 7, when the iDEN system wakes up, the mobile up frame 702 uses one time (eg, time slot 3) and its down frame 701 uses the same time slot (ie, time slot). 3). In a preferred embodiment of the present invention, the downlink time slot (slot 3) in the uplink frame 702 is designed to be one hour after the uplink time slots (701) (slot 3). Since the ascending and descending time slots are temporally staggered, the use of time switches 608,609 avoids RF duplexers in the mobile. [0040] When a mobile makes a two-master delivery telephone call (one or more speakers), the caller initially belongs to partial call group 102 (the caller is defined as the first master). The caller is assigned one of the uplink time slots (eg, time slot 3) from the fixed infrastructure 103. The downlink time slots (slot 3) of other callers belonging to the partial listening group 130 for the same uplink slot number are also assigned from the fixed infrastructure 103. If one of the listeners in the partial listening group 130 requests a conversation and the request is approved by the fixed infrastructure 103, the listener moves from the partial listening group 130 to the partial calling group 101. In a preferred embodiment of the invention, a pair of ascending and descending time slots (eg, time slot 4) is assigned to the new speaker (the second speaker is defined as the second master). The same downlink time slot (slot 3) is assigned to the first speaker (first master) as an uplink time slot in order to give the first speaker (first master) the ability to listen. New descent time slots (time slot 2) other than the same descent time slot (slot 3) need to be assigned to partial listening group 130. [0041] When the first speaker (first master) ends the conversation, its ascending and descending time slots (Tx / Rx time slots 3) are released. The descent time slot (Rx time slot 4) of the second speaker (second master) is also released. To save resources for other calls, the uptime slot number (Tx time slot number 4) of the second speaker is changed to the same downtime slot number (here, time slot number 2). Then, the second speaker (second master) is appointed as the first speaker (first master). [0042] If N participants wish to have a conversation, an additional time slot is required in addition to the N pairs of send and receive time slots. Here, N is the number of members of the partial call group 103. In the iDEN system, there are only 6 time slots in one frequency channel. If N is 5 or greater, some of the participants in partial call group 103 will need to move to other frequency channels. This is because one downtime slot needs to be reserved for the partial listening group 130. [0043] A typical iDEN delivery group call has a supervision mode. If a participant has supervisor priority, the audio from the downlink time slot replaces the audio of the current broadcast speaker and is transmitted to the listeners in partial listening group 130. In the present invention, the voice of the administrator and the voice of the current speaker are added to all listeners in the partial listening group. [0044] The present invention generally provides methods and devices for duplex communication within a calling group. Utilizing efficient CDMA or TDMA system resource allocation methods allows partial call groups of subscriber equipment to speak in wireless duplex conference calls, while others in potentially very large call groups. Members can attend and participate in conversations if they so desire. In this way, it is possible to achieve more natural group-type communication without imposing an excessive burden of using wireless communication resources. [0045] Although the present invention has been described above with reference to some preferred embodiments, one of ordinary skill in the art can make many modifications and modifications without departing from the novel spirit and scope of the invention. Let's do it. For example, in the preferred embodiment, it was described that the voice signal of each user is subtracted from the addition signal, but it is also possible to construct the addition signal without the voice of each user by using another method. is there. For example, instead of subtracting the subscriber's voice signal with adder 415, in another embodiment the adder 415 is removed and the processing device 418 sends the resulting adder signal to that subscriber. It is also possible to simply prevent the subscriber's voice signal from being transmitted to the adder 412. [Simple explanation of drawings] FIG. 1 is a block diagram of a wireless communication system according to the present invention. FIG. 2 is a flowchart showing a method used in the fixed infrastructure according to the present invention. FIG. 3 shows a table that can be incorporated when establishing a call group call according to the present invention. FIG. 4 is a block diagram illustrating the operation of the wireless communication system of FIG. 1 according to the present invention. FIG. 5 is a flowchart showing a method used in the subscriber device according to the present invention. FIG. 6 is a block diagram illustrating the operation of the wireless communication system of FIG. 1 according to another embodiment of the present invention. FIG. 7 is a block diagram showing a time slot distribution of the TDMA wireless communication system of FIG.