JP2013026889A - Communication method, communication system, radio terminal and base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve multi-party communication without a server to compose voice data.SOLUTION: A communication method includes the steps of: from a first radio terminal, requesting for connection to second and third radio terminals; by a base station corresponding to the first radio terminal, establishing a first connection associated with communication between the first radio terminal and the second radio terminal, and establishing a second connection, associated with communication between the first radio terminal and the third radio terminal, with a different frequency from the first connection; from the first radio terminal, instructing the second radio terminal to connect to the third radio terminal; from the second radio terminal, requesting for connection to the third radio terminal in response to the instruction from the first radio terminal; and by a base station corresponding to the second radio terminal, establishing a third connection associated with communication between the second radio terminal and the first radio terminal, and establishing a fourth connection, associated with communication between the second radio terminal and the third radio terminal, with a different frequency from the third connection.

Description

  The present invention relates to a communication method, a communication system, a wireless terminal, and a base station capable of multi-party communication.

  Currently, 3GPP (Third Generation Partnership Project) is proceeding with specifications for LTE (Long Term Evolution), which is a next generation communication method. Furthermore, the specification of LTE-A (LTE-Advanced), which is a standard developed from LTE, is also being studied.

  LTE-A is required to realize higher-speed and large-capacity communication than LTE. Therefore, LTE-A is supposed to support a wider frequency range than LTE. According to the examination so far, the maximum transmission bandwidth of LTE is 20 MHz, whereas the maximum transmission bandwidth of LTE is extended to 100 MHz.

  However, in view of the radio wave usage situation in various countries around the world, it is not easy to secure a continuous wide frequency band for LTE-A. It is also necessary to maintain backward compatibility (backward compatibility) with LTE as much as possible. Therefore, introduction of a wireless communication technology called carrier aggregation (CA) is being studied. In this carrier aggregation, the maximum transmission bandwidth is expanded to 100 MHz by using a plurality of carriers corresponding to 20 MHz that is the maximum transmission bandwidth of LTE. Such a carrier up to 20 MHz is called a component carrier (CC).

  By using such carrier aggregation, high-speed and large-capacity communication is realized between the base station and the mobile station (terminal: User Equipment). The carrier aggregation was agreed at the 3GPP RAN1 # 53b meeting (see “5.5 Carrier Aggregation” in Non-Patent Document 1).

  By the way, a service called PoC (Push-to-Talk over Cellular) that provides one-to-N group communication using a wireless telephone terminal device has been proposed. In such a service, a terminal device to which a right to speak is given from the server side transmits voice data to the server, and the server distributes the transmitted voice data to other connected terminal devices in almost real time. As described above, when a group call (multi-party communication) is realized between a plurality of wireless terminals, the plurality of wireless terminals communicate with a server connected via a wireless line, thereby the server. Voice data and the like can be transmitted to other wireless terminals connected to the.

JP 2007-134989 A

3GPP Organizational Partners, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 10)" , 3GPP TS 36.300 V10.3.0 (2011-03)

  A system in which each wireless terminal such as a teleconferencing system can transmit audio data at an arbitrary timing, not a system in which only a wireless terminal to which a speaking right such as PoC is given can transmit audio data. think of. In this case, as a form of development of the system as described above, a server to which each wireless terminal is connected is installed, and voice data transmitted from each wireless terminal via the corresponding wireless line is synthesized, It is assumed that the synthesized voice data is distributed to each wireless terminal. However, when such a configuration is adopted, it is necessary to sequentially synthesize audio data from a plurality of wireless terminals to generate audio, and a delay due to processing occurs in the server. Therefore, it is not suitable for a system in which users of a plurality of wireless terminals such as a telephone conference system talk simultaneously, and a server having a high processing capability must be used.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a communication method, a communication system, and a wireless communication that realize multi-party communication while eliminating the need for a server that synthesizes voice data. It is to provide a terminal and a base station.

  According to one aspect of the present invention, a communication method for performing multi-party communication between a plurality of wireless terminals is provided. In the communication method, the first wireless terminal requests connection to the second and third wireless terminals, and the base station corresponding to the first wireless terminal transmits the first wireless terminal and the second wireless terminal. Establishing a first connection associated with the communication with the terminal and a second connection having a frequency different from the first connection associated with the communication between the first wireless terminal and the third wireless terminal. The first wireless terminal instructs the second wireless terminal to connect to the third wireless terminal, and the second wireless terminal responds to the instruction from the first wireless terminal. Requesting a connection to the third wireless terminal; and a third connection associated with communication between the second wireless terminal and the first wireless terminal by a base station corresponding to the second wireless terminal; A frequency different from the third connection associated with the communication between the second wireless terminal and the third wireless terminal And establishing a fourth connection.

  According to another aspect of the present invention, a communication system for performing multi-party communication is provided. The communication system includes a plurality of wireless terminals and a plurality of base stations that provide a predetermined cell area. The wireless terminal is either means for requesting connection to a plurality of wireless terminals, means for instructing one of the plurality of wireless terminals that requested connection to connect to the remaining wireless terminals, or Means for requesting connection to the designated wireless terminal in response to an instruction to connect to the wireless terminal. The base station includes means for establishing a plurality of connections having different frequencies from each other in response to a connection request from a wireless terminal present in a cell area provided by the base station to the plurality of wireless terminals.

  According to still another aspect of the present invention, a wireless terminal capable of multi-party communication is provided. The wireless terminal includes means for requesting connection to other wireless terminals. In response to a connection request to a plurality of wireless terminals, a base station that provides a cell area where the wireless terminal exists establishes a plurality of connections having different frequencies. The wireless terminal further responds to means for instructing connection to the remaining wireless terminal to one of the plurality of wireless terminals that have requested connection, and an instruction to connect to one of the wireless terminals. And means for requesting connection to the designated wireless terminal.

  According to still another aspect of the present invention, a base station capable of multi-party communication is provided. The base station includes means for establishing a plurality of connections having different frequencies from each other in response to a connection request from a wireless terminal present in a cell area to be provided to the plurality of wireless terminals.

  ADVANTAGE OF THE INVENTION According to this invention, communication between many persons is realizable, making the server which synthesize | combines audio | voice data unnecessary.

It is a schematic diagram which shows the whole structure of the communication system according to embodiment of this invention. It is a block diagram which shows schematic structure of the radio | wireless terminal (UE) according to embodiment of this invention. It is a block diagram which shows schematic structure of the base station (BS) according to embodiment of this invention. It is an example of the user interface which UE used by the communication system according to embodiment of this invention provides. It is a schematic diagram which shows the example of allocation of the component carrier corresponding to FIG. It is a sequence diagram which shows the process which concerns on the allocation of the component carrier shown in FIG. FIG. 6 is a schematic diagram showing a dedicated line between UEs using the component carrier shown in FIG. 5. It is a schematic diagram which shows the procedure in the case of performing communication between four persons in the communication system according to embodiment of this invention. It is a flowchart in UE which becomes the leader which shows the procedure for establishing the connection which concerns on the communication between many persons shown in FIG. It is a flowchart in UE which becomes the leader which shows the procedure for establishing the connection which concerns on the communication between many persons shown in FIG. It is a flowchart in UE other than the leader which shows the procedure for establishing the connection which concerns on the communication between multiple persons shown in FIG. It is a flowchart in UE which becomes a leader in the process which performs a connection process sequentially in order with a quick response. It is a flowchart in UE other than a leader in the process which performs a connection process sequentially in order with a quick response.

  Embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to these embodiments, and can be implemented in various modes without departing from the spirit of the present invention. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

<1. System configuration>
First, a typical configuration of a communication system according to the embodiment of the present invention will be described.

  FIG. 1 is a schematic diagram showing an overall configuration of a communication system 1 according to the embodiment of the present invention. As a typical example, it is assumed that the communication system 1 supports a communication scheme according to the LTE scheme or the LTE-A scheme.

  Referring to FIG. 1, a communication system 1 includes a radio terminal (hereinafter referred to as “UE (User Equipment)”) 100 that is a mobile station, and a plurality of base stations (hereinafter also referred to as “BS”). 200-1 to 200-3, a mobile management device (Mobility Management Entity: hereinafter also referred to as “MME”) 300 as a control device, and a core network 400.

  The UE 100 is typically a mobile phone, a PDA (Personal Digital Assistant), a data communication terminal, and the like, and exchanges data with the other party via any BS.

  Each of the BSs 200-1 to 200-3 (hereinafter collectively referred to as “BS200”) can transmit and receive a plurality of independent radio signals having different frequencies. That is, the BS 200 supports carrier aggregation, and exchanges data with a single UE 100 using a plurality of component carriers, as will be described later.

  In carrier aggregation according to the LTE scheme or LTE-A scheme, it is generally assumed that a series of data is transmitted and received using a plurality of component carriers. In the communication system according to the present embodiment, component carriers that each independently transmit and receive data are allocated to a single UE 100. By adopting such component carrier allocation, communication can be performed in parallel between a single UE 100 and a plurality of other UEs 100.

  In the example shown in FIG. 1, BSs 200-1 to 200-3 cover cell areas C201 to C203, respectively, and a plurality of component carriers are prepared in each of cell areas C201 to C203. That is, each of BS 200-1 to 200-3 provides a predetermined cell area. And these component carriers are suitably allocated with respect to UE100.

  When frequency bands are assigned discretely, component carriers are assigned to the respective frequency bands. In this case, for example, a component carrier in the first frequency band and a component carrier in the second frequency band may be assigned to a single UE 100.

  The BS 200 typically includes an evolved base station (evolved Node B: eNB), a small evolved base station (Home evolved Node B: HeNB), and the like.

  The MME 300 mediates the connection of the BS 200 existing in the cell area provided by the BS 200 managed by the own station to the core network 400, and also exists in the cell of the BS 200 existing in the cell area provided by the own station. Manage location information. Basically, a plurality of BSs 200 are connected to the MME 300.

  A large number of BSs 200 are connected to the core network 400 via a plurality of MMEs 300 to form a wide area network. In the LTE scheme or the LTE-A scheme, it is assumed that the core network 400 is a network in which all information is packetized.

<2. Overview>
Communication system 1 according to the present embodiment provides multi-party communication between a plurality of UEs 100. In the example illustrated in FIG. 1, an example in which three-party communication is performed between the UE 100-1 to the UE 100-3 is illustrated.

  In the communication system 1 according to the present embodiment, when such multi-party communication is realized, component carriers are used between all the combinations of two UEs 100 among UEs 100 participating in multi-party communication. Establish a dedicated line. For example, as shown in FIG. 1, a dedicated line 1 is established between UE1 and UE2, a dedicated line 2 is established between UE1 and UE3, and a dedicated line 3 is established between UE2 and UE3. The

  In such a state, the voice uttered by the user of UE1 is transmitted to UE2 and UE3 via dedicated line 1 and dedicated line 2, respectively. The dedicated line 1 and the dedicated line 2 are independent of each other. That is, UE1 sends data to UE2 and UE3 independently through dedicated lines 1 and 2, respectively. Similarly, the voice emitted by the user of UE2 is transmitted to UE2 and UE3 via dedicated lines 1 and 3, respectively, and the voice emitted by the user of UE3 is transmitted to UE1 and UE3 via dedicated lines 3 and 2, respectively. Sent to UE2.

  Each UE synthesizes and outputs the received voice from the other UE. For example, UE1 synthesizes and outputs data received from UE2 and UE3 independently via dedicated lines 1 and 2, respectively. This voice synthesis is typically realized simply by superimposing a plurality of voice signals and outputting them to a single speaker, and does not increase the processing load associated with the voice synthesis.

In this way, by establishing a dedicated line between each of a plurality of UEs using a component carrier, multi-party communication can be realized without increasing the processing load. In communication system 1 according to the present embodiment, dedicated communication of _n C ₂ = n × (n−1) / 2 is required in order for n people to perform multi-party communication. At this time, each BS 200 allocates (n-1) line component carriers to the corresponding UE.

  Each dedicated line must be capable of bidirectional communication. As a method for realizing such bi-directional communication, uplink and downlink component carriers may be allocated, or one component carrier may be switched between uplink and downlink at predetermined intervals. Good. That is, one component carrier may be multiplexed in a time division manner.

  As described above, in the communication system 1 according to the present embodiment, when n persons perform multi-party communication, each of UE1 to UEn possessed by user 1 to user n has (n-1) line component carriers. And for each user, a dedicated line using a component carrier is established with every other user. Note that such a dedicated line between users becomes a route through the MME 300. In this way, by establishing a dedicated line with every other user for each user, multi-party communication can be realized without installing a server for centrally managing voice data. Thus, since it is not necessary to perform voice data synthesis processing between users who participate in multi-party communication without installing a server, the processing load on the MME 300 is not increased. As a result, a delay due to processing in the MME 300 does not occur.

  In addition, by using carrier aggregation, component carriers are allocated to dedicated lines between users, so that communication can be performed while occupying the allocated bandwidth between users. In this way, since the allocated bandwidth can be monopolized, it is possible to achieve the required throughput for each call between users and to perform optimum communication control according to the terminal capability. Thereby, radio resources can be used effectively.

  Further, in communication system 1 according to the present embodiment, component carriers are allocated for each dedicated line corresponding to users, and therefore there is a case where there is an increase or decrease (addition or deletion) of users participating in multi-party communication. However, since communication control can be performed on a component carrier basis, participants can be added or deleted more flexibly.

<3. Device configuration>
Next, each device constituting the communication system 1 shown in FIG. 1 will be described.

(3-1: Configuration of Radio Terminal (UE) 100)
First, the configuration of radio terminal 100 used in communication system 1 according to the present embodiment will be described. FIG. 2 is a block diagram showing a schematic configuration of radio terminal (UE) 100 according to the embodiment of the present invention.

  Referring to FIG. 2, UE 100 has a number of transmission / reception circuits corresponding to available component carriers as a radio unit corresponding to carrier aggregation. In the example illustrated in FIG. 2, a configuration in which two component carriers can be used will be described. That is, the UE 100 is equipped with a plurality of radio signal transmission / reception circuits corresponding to the respective component carriers. More specifically, the wireless terminal 100 is provided with transmitting antennas 114-1 and 114-2 for transmitting wireless signals and receiving antennas 118-1 and 118-2 for receiving wireless signals. A housing 150 is included. Case 150 includes control unit 104, signal processing unit 102, transmission units 112-1 and 112-2, and reception units 116-1 and 116-2.

  The reception antenna 118-1, the reception unit 116-1, the signal processing unit 102, the transmission unit 112-1, and the transmission antenna 114-1 correspond to a transmission / reception circuit for transmitting and receiving the first component carrier. Reference numeral 118-2, the reception unit 116-2, the signal processing unit 102, the transmission unit 112-2, and the transmission antenna 114-2 correspond to a transmission / reception circuit for transmitting and receiving the second component carrier.

  The signal processing unit 102 processes a radio signal exchanged with the BS 200 that manages the cell area in which the device itself is present. More specifically, the signal processing unit 102 outputs information to be transmitted to the BS 200 to the transmission units 112-1 and 112-2 in accordance with an internal command given from the control unit 104. Transmitters 112-1 and 112-2 perform encoding processing, modulation processing, and up-conversion on the information received from signal processing unit 102, and transmit radio signals obtained as a result thereof to corresponding transmission antennas 114-1. , 114-2. In addition, the receiving units 116-1 and 116-2 perform down-conversion, demodulation processing, and decoding processing on the radio signals received via the corresponding receiving antennas 118-1 and 118-2, and are obtained as a result. The information is output to the signal processing unit 102.

  The control unit 104 includes, as main components, a processor, a nonvolatile memory for holding a program executed by the processor, and a volatile memory functioning as a work memory. Further, the control unit 104 includes a multi-party communication logic 105. This logic is typically provided by the control unit 104 executing a program stored in advance. For example, modules corresponding to the multi-party communication logic 105 are stored in advance in a non-volatile memory, and a function related to multi-party communication is provided by the control unit 104 reading and executing these modules.

  In the multi-person communication according to the present embodiment, a certain user takes the lead and notifies other users of participation. For this reason, the multi-party communication logic 105 provides (1) a function of notifying participation and (2) a function of notifying participation. In any case, the multi-party communication logic 105 performs processing related to addition and deletion of component carriers used for exchange of radio signals with the corresponding BS 200.

  More specifically, the multi-party communication logic 105 (1) is an identifier indicating that the communication is multi-party communication using carrier aggregation for the UE 100 specified by the user operation as a function of notifying participation. And has a function of starting communication. At this time, the multi-party communication logic 105 requests connection to a plurality of UEs 100.

  The multi-party communication logic 105 also has a function of instructing the UE 100 to make a call to the other participant's UE 100 simultaneously with the call to the participant's UE 100. More specifically, the multi-party communication logic 105 instructs one UE 100 out of a plurality of UEs 100 that requested connection to connect to the remaining UEs 100. With this function, a dedicated line is established between the UEs 100 of the participants who are not the leaders. It should be noted that the process is distinguished from normal communication / call by adding an identifier indicating that the communication is between multiple parties to the incoming call.

  Further, when the communication between the multi-party communication logic 105 is instructed to make a call from the other UE 100 to the other UE 100 as a function of (2) participation notification, the multi-party communication logic 105 To automatically make a call. That is, the multi-party communication logic 105 requests connection to the instructed UE 100 in response to an instruction to connect to any UE 100.

  Note that some or all of the functions provided by the control unit 104 may be implemented as dedicated hardware (integrated circuit). In this case, in addition to the functions provided by the control unit 104, all of the functions provided by the signal processing unit 102, the transmission units 112-1 and 112-2, and the reception units 116-1 and 116-2. Alternatively, some chips may be included in one chip. Furthermore, it is possible to use a SoC in which components such as a processor, a memory, and a controller for peripheral devices are integrated into one chip.

  As an alternative configuration, all or part of the functions provided by the control unit 104, the signal processing unit 102, the transmission units 112-1 and 112-2, and the reception units 116-1 and 116-2 are implemented as software. May be. In this case, an arithmetic unit (processor) such as a CPU or DSP executes a preinstalled instruction set.

  The casing 150 further includes a display unit 152 for displaying various types of information, a microphone 154 for acquiring user's voice, a speaker 156 for reproducing received voice, and a user operation. An input unit 158.

  The display part 152 displays the information which concerns on the user (UE100) participating in communication between many people. Then, information related to the participating users (telephone number, image, character information data, etc.) is displayed during connection of multi-party communication and connection processing.

  The input unit 158 includes a touch pad, a cross key, a numeric keypad, and the like, and accepts designation of a user (UE 100) participating in multi-party communication. Typically, the user operates the input unit 158 to select a plurality of connection destination telephone numbers. As a procedure for establishing a dedicated line for multi-party communication, simultaneous connection to a plurality of selected users (UE 100) may be performed simultaneously or individually. Also. When ending the multi-party communication, the lines may be disconnected all at once, or individual lines may be disconnected in order.

(3-2: Configuration of Base Station (BS) 200)
First, the configuration of BS 200 used in communication system 1 according to the present embodiment will be described. FIG. 3 is a block diagram showing a schematic configuration of base station (BS) 200 according to the embodiment of the present invention.

  Referring to FIG. 3, BS 200 basically has a number of transmission / reception circuits corresponding to component carriers that can be provided. More specifically, the BS 200 includes control units 202-1 to 202-n, signal processing units 210-1 to 210-n, transmission units 212-1 to 212-n, and transmission antennas 214-1 to 214. -N, receiving units 216-1 to 216-n, and receiving antennas 218-1 to 218-n. Further, the BS 200 includes a central processing unit 204, an upper network interface (I / F) 206, and a control interface (I / F) 208.

  Each of the transmission / reception circuits of the BS 200 exchanges data (radio signals) with the UE 100 using the allocated component carrier. That is, each of the control units 202-1 to 202-n outputs user data, control information, management information, and the like given from the central processing unit 204 to the corresponding signal processing units 210-1 to 210-n, and The user data decrypted by the processing units 210-1 to 210-n is output to the central processing unit 204.

  The signal processing units 210-1 to 210-n process radio signals exchanged with the UE 100 existing in the area where the corresponding component carrier reaches. More specifically, the signal processing units 210-1 to 210-n receive user data, control information, management information, and the like given from the corresponding control units 202-1 to 202-n, and transmit them to the UE 100. The power information is output to the corresponding transmission units 212-1 to 212-n. Transmitting sections 212-1 to 212-n perform coding processing, modulation processing, and up-conversion on information received from corresponding signal processing sections 210-1 to 210-n, and wireless signals obtained as a result thereof Are radiated to the outside via the corresponding transmitting antennas 214-1 to 214-n. In addition, the reception units 216-1 to 216-n perform down-conversion, demodulation processing, and decoding processing on the radio signals received via the corresponding reception antennas 218-1 to 218-n, and obtain the result. The received information is output to the corresponding signal processing units 210-1 to 210-n.

  The central processing unit 204 includes, as main components, a processor, a nonvolatile memory for holding a program executed by the processor, and a volatile memory functioning as a work memory. Further, the central processing unit 204 includes a multi-party communication logic 205. The multi-party communication logic 205 is typically provided by the central processing unit 204 executing a program stored in advance. For example, modules corresponding to the multi-party communication logic 205 are stored in advance in a non-volatile memory, and the central processing unit 204 reads and executes these modules to provide functions as described later.

  The multi-party communication logic 205 executes component carrier assignment and various procedures in order to realize multi-party communication involving a plurality of UEs 100. More specifically, when the multi-party communication logic 205 receives a call including an identifier indicating multi-party communication, the multi-party communication logic 205 transfers the call to the callee UE 100 while including the identifier. The multi-party communication logic 205 receives a call from the UE 100 existing in the cell area managed by the own station or a call from the UE 100 existing in the cell area managed by another BS 200. If an identifier indicating that the call is multi-party communication is included in the call, a different component carrier is assigned to each call. That is, the multi-party communication logic 205 responds to a connection request from the UE 100 existing in the cell area provided by the own station to the other plurality of UEs 100, and connects a plurality of connections (component carriers) having different frequencies. Establish.

  Further, the multi-party communication logic 205 is in a call even when there are a plurality of calls including an identifier indicating multi-party communication with respect to the UE 100 existing in the cell area managed by the own station ( It provides a function that can respond to any outgoing call.

  Note that some or all of the functions provided by the central processing unit 204 may be implemented as dedicated hardware (integrated circuit). In this case, in addition to the functions provided by the central processing unit 204, the control units 202-1 to 202-n, the signal processing units 210-1 to 210-n, the transmission units 212-1 to 212-n, and In addition, all or part of the functions provided by the receiving units 216-1 to 216-n may be integrated into one chip. Furthermore, it is possible to use a SoC in which components such as a processor, a memory, and a controller for peripheral devices are integrated into one chip.

  As an alternative configuration, provided by the control units 202-1 to 202-n, signal processing units 210-1 to 210-n, transmission units 212-1 to 212-n, and reception units 216-1 to 216-n. All or a part of the functions may be implemented as software. In this case, an instruction set in which a computing device (processor) such as a CPU (Central Processing Unit) or DSP (Digital Signal Processor) is installed in advance is executed.

  The host network interface 206 exchanges user data, control information, management information, and the like with the MME 300 that manages its own station. Similarly, the control interface 208 exchanges control information with other BSs 200.

<4. Establishment of dedicated line>
Next, a dedicated line establishment process will be described with reference to FIGS. As an example, as shown in FIG. 1, a case where three-party communication is performed between UE1 to UE3 owned by users 1 to 3 will be described. It is assumed that UE1 to UE3 exist in cell areas C201 to C203 provided by BS1 to BS3, respectively. That is, UE1 possessed by user 1 can communicate with BS1 via a radio signal. Similarly, UE2 possessed by user 2 can communicate with BS2 via a radio signal, and UE3 possessed by user 3 can communicate with BS3 via a radio signal. Of course, there may be a plurality of UEs 100 participating in multi-party communication in the same BS 200.

  First, in order to start communication between multiple people, a certain user becomes a leader and notifies other users of participation.

  FIG. 4 is an example of a user interface provided by UE 100 used in communication system 1 according to the embodiment of the present invention. As shown in FIG. 4A, the display unit 152 of the UE 100 displays a list of users who can be notified of participation in multi-party communication. The user operates the input unit 158 of the UE 100 to select a user who should participate in the multi-person communication. The display unit 152 displays four users (Mr. A, Mr. B, Mr. C, and Ms. D). As shown in FIG. 4B, the user of UE1 has two users (Mr. A). And Mr. B) are selected. It is assumed that Mr. A is a user 2 who owns UE2, and Mr. B is a user 3 who possesses UE3. Then, as shown in FIG. 4C, when the user presses “call”, UE1 makes a call to UE2 and UE3 in parallel. At this time, UE1 transmits to UE2 a parameter instructing “calling to UE3” together with the call. That is, the private lines 1 and 2 are established by the initiative of the UE 1, and the UE 2 that receives the instruction from the UE 1 establishes the private line 3.

  FIG. 5 is a schematic diagram illustrating an example of component carrier allocation corresponding to FIG. 1, FIG. 6 is a sequence diagram illustrating processing related to component carrier allocation illustrated in FIG. 5, and FIG. It is a schematic diagram which shows the dedicated line between UE using the component carrier shown.

  Referring to FIG. 5 and FIG. 6, when the user selects a user who participates in the multi-party communication (sequence SQ2), UE1 calls UE2 and UE3 (sequence SQ10). That is, UE1 that is the first radio terminal requests connection to UE2 and UE3 that are the second and third radio terminals.

  In response to a call from UE1 to UE2 and UE3, BS1, which provides a cell area where UE1 exists, allocates component carrier 1A for communication between UE1 and UE2, and between UE1 and UE3 The component carrier 1B is assigned to the communication between them (sequence SQ12). And UE1 starts the radio | wireless communication regarding UE2 between BS1 using component carrier 1A, and starts the radio | wireless communication regarding UE3 between BS1 using component carrier 1B. That is, the base station (BS1) corresponding to UE1 which is the first wireless terminal is associated with the first connection (component carrier 1A) associated with the communication between UE1 and UE2, and with the communication between UE1 and UE3. The second connection (component carrier 1B) having a frequency different from that of the first connection (component carrier 1A) is established.

  At this time, the BS 1 controls a modulation scheme, a MIMO (Multiple Input Multiple Output) scheme, and the like according to the throughput required in each of the component carriers 1A and 1B and the capability of the UE1.

  This call from UE1 to UE2 includes a parameter for instructing a call from UE2 to UE3. That is, UE1 instructs UE2 to connect to UE3.

  Subsequently, the BS 1 makes a call from the UE 1 to the UE 2 and a call from the UE 2 to the UE 3 to the BS 2 that provides a cell area where the UE 2 owned by the user 2 exists via the mobile management device (MME) 300. A parameter for instructing a call is transmitted (sequence SQ14). Further, BS1 transmits a call from UE1 to UE3 via MME 300 to BS3 that provides a cell area where UE3 owned by user 3 is present (sequence SQ14). This call includes an identifier indicating that the communication is multi-party communication using carrier aggregation.

  When BS2 receives an incoming call including an identifier indicating that the communication is multi-party from UE1, via MME300, BS2 transmits the incoming call to UE2 (sequence SQ20). At this time, BS2 allocates component carrier 2A to UE2 to transmit this incoming call (sequence SQ16). BS2 controls the modulation scheme and MIMO scheme of component carrier 2A so as to match the throughput of component carrier 1A included in the dedicated line between UE1 and UE2 (sequence SQ18). That is, BS1 corresponding to UE1 and BS2 corresponding to UE2 are controlled so that transmission performance substantially matches between component carrier 1A and component carrier 2A. Thereby, the transmission quality of the dedicated line between UE1 and UE2 is equalized. Therefore, negotiation is performed between BS1 and BS2, and the component carriers assigned by each are optimized.

  As a specific example, if the specification or radio wave environment of the component carrier 2A assigned to the UE 2 possessed by the user 2 does not satisfy the throughput of the corresponding component carrier 1A, the BS 2 reduces the communication rate and changes the component The BS 1 is notified so as to reduce the resources allocated to the carrier 1A. Alternatively, the BS 1 notifies the control of the modulation scheme and the MIMO scheme so as to reduce the throughput of the component carrier 1A. In response to the notification from BS2, BS1 changes the resource allocated to component carrier 1A, the modulation scheme, and the like so as not to exceed the throughput that can be achieved by component carrier 2A.

  Then, when the user 2 operates the UE 2 and responds to the call from the user 1 (UE 1), a dedicated line between the user 1 (UE 1) and the user 2 (UE 2) is established.

  Similarly, when receiving an incoming call including an identifier indicating that the communication is multi-party from UE1, via BS M3, BS 3 transmits the incoming call to UE 3 (sequence SQ30). At this time, BS 3 allocates component carrier 3A to UE 3 in order to transmit this incoming call (sequence SQ26). Similarly to the above, BS1 and BS3 are such that the modulation schemes and MIMO schemes of the corresponding component carriers are such that the respective throughputs of component carriers 1B and 3A included in the dedicated line between UE1 and UE3 are equal to each other. Are controlled (sequence SQ30).

  And the user 3 operates UE3 and responds to the call from the user 1 (UE1), The private line between the user 1 (UE1) and the user 3 (UE3) is established.

  In addition, when UE2 receives a parameter instructing “calling to user 3” from UE1, UE2 automatically sends a call with an identifier indicating that the communication is multi-party communication using carrier aggregation to UE3. (Sequence SQ40). That is, UE2 requests connection to UE3 in response to an instruction from UE1.

  In response to a call from UE2 to UE3, BS2 that provides a cell area in which UE2 exists allocates a component carrier 2B for communication between UE2 and UE3. And UE2 starts the radio | wireless communication regarding UE3 between BS2 using component carrier 2B. That is, BS2 corresponding to UE2 establishes a connection (component carrier 2B) associated with communication between UE2 and UE3 at a frequency different from the connection associated with communication between UE2 and UE1 (component carrier 2A). .

  Subsequently, the BS 2 transmits a call from the UE 2 to the UE 3 via the MME 300 to the BS 3 that provides a cell area where the UE 3 possessed by the user 3 exists. This call includes an identifier indicating that the communication is multi-party communication using carrier aggregation. In response to a call from UE2 to UE3, BS2 that provides a cell area in which UE2 exists assigns component carrier 2B to communication between UE2 and UE3 (sequence SQ42). And UE2 starts the radio | wireless communication regarding UE3 between BS2 using component carrier 2B.

  Subsequently, BS2 transmits a call from UE2 to UE3 via BS 300 to BS3 that provides a cell area where UE3 owned by user 3 is present (sequence SQ44). This call includes an identifier indicating that the communication is multi-party communication using carrier aggregation.

  When BS 3 receives an incoming call including an identifier indicating that the communication is multi-party from UE 2 via MME 300, BS 3 transmits the incoming call to UE 3 (sequence SQ50). At this time, BS 3 allocates component carrier 3B to UE 3 in order to transmit this incoming call (sequence SQ46). That is, the BS 3 corresponding to the UE 3 has a connection (component carrier 3A) associated with the communication between the UE 3 and UE 1 and a connection (component carrier 3A) associated with the communication between the UE 3 and the UE 2 with a frequency different from that of the component carrier 3A. 3B).

  Similarly to the above, BS2 and BS3 are such that the modulation schemes and MIMO schemes of the corresponding component carriers are set so that the respective throughputs of component carriers 2B and 3B included in the dedicated line between UE2 and UE3 are equal to each other. Is controlled (sequence SQ48).

  Then, when the user 3 operates the UE 3 and responds to the call from the user 2 (UE 2), a dedicated line between the user 2 (UE 2) and the user 3 (UE 3) is established.

  In the case of performing communication between three parties as shown in FIG. 5, the relationship between the UE after the establishment of the dedicated line and the assigned component carrier is as shown in FIG. Similarly, when there are n users participating in multi-person communication, similarly, (n-1) component carriers are allocated to each user and dedicated lines are connected to all other users. Can be established.

<5. Procedure for establishing a dedicated line (1)>
Next, a procedure for establishing a dedicated line using carrier aggregation between each user in multi-party communication involving more participants will be described. The dedicated line between the UEs 100 in the multi-party communication described below is established by allocating component carriers among all the UEs 100. Further, when the BS 200 receives a call including an identifier indicating communication between multiple parties from the UE 100 existing in a cell area managed by the BS, the BS 200 allocates different component carriers to which the call is to be made. Then, establish a dedicated line using carrier aggregation.

  As an example, a case where four-way communication involving users 1 to 4 (UE1 to UE4) is described will be described. In this case, UE1 possessed by user 1 makes a sequential call in the order of UE2, UE3, and UE4. Then, the UE 2 is instructed to make a call to the UE 3 and the UE 4 that can connect to the UE 1. This establishes a connection between UEs other than the leader UE1.

  FIG. 8 is a schematic diagram showing a procedure when performing communication between four parties in communication system 1 according to the embodiment of the present invention. Referring to FIG. 8, UE1 calls sequentially in the order of UE2, UE3, and UE4. At this time, when the BS providing the cell area in which UE1 is present receives a call including an identifier indicating that the communication is multi-party communication from UE1, components different from each other for each call to UE2, UE3, and UE4 Allocate carriers and establish a dedicated line using carrier aggregation.

  UE1 instructs UE2 to make a call in accordance with the presence / absence of responses from UE3 and UE4. For example, if there is a response from both UE3 and UE4, UE1 instructs UE2 to make a call to UE3 and UE4, respectively. The UE 2 receiving the call instruction from the UE 1 makes a call to the instructed UE following the response to the call from the UE 1. At this time, the UE 2 also transmits a call instruction to other UEs to any one of the instructed call destination UEs. This call instruction includes the telephone number of the target UE. In this way, a UE that has received a call instruction from another UE repeats a call to another UE. If only one call destination is finally designated, a necessary number of dedicated lines can be established between a plurality of designated UEs.

  FIG. 9 and FIG. 10 are flowcharts in the UE serving as a leader showing a procedure for establishing a connection related to the communication between multiple persons shown in FIG. FIG. 11 is a flowchart in a UE other than the leader showing a procedure for establishing a connection related to the multi-party communication shown in FIG. In addition, in the flowchart shown in FIGS. 9-11, the user 1 possessing UE1 shall become a leader and start communication between many persons.

(5.1: Processing procedure in UE as lead)
Referring to FIG. 9 and FIG. 10, user 1 operates UE 1 that he / she owns to specify that multi-user communication is to be performed, and selects UE 2 to UE 4 which are owned by users 2 to 4 who participate in the communication. (Step S102). This user selection method is performed by inputting the telephone number of the corresponding UE.

  Then, the UE1 possessed by the user 1 determines the order of calling the selected UE2 to UE4, and calls the one UE determined as the first call destination (step S104). . As a method for determining the order of making a call, for example, a method of determining according to the order in which a user who is a leader inputs a telephone number for selecting another user may be considered. Here, an example is shown in which a call is first made to UE2.

  At this time, an identifier indicating that the communication is multi-party communication is added to the call from UE1 to UE2. In addition, since the users 2 to 4 are not necessarily in a state in which communication is possible, communication is sequentially established according to the following procedure.

  UE1 judges whether there is a response from UE2 after the call to UE2 (step S110). If there is a response from UE2 (YES in step S110), UE1 establishes a connection with UE2 (step S112). That is, the BS corresponding to the cell where UE1 exists and the BS corresponding to the cell where UE2 exists allocate component carriers for establishing a dedicated line between UE1 and UE2 to UE1 and UE2, respectively.

  Subsequently, UE1 calls the UE corresponding to the next order. In this example, UE1 makes a call to UE3, which is the next call destination (step S114). An identifier indicating that the communication is multi-party communication is also added to the call from UE1 to UE3.

  UE1 judges whether there exists a response from UE3 after the call to UE3 (step S120). If there is a response from UE3 (YES in step S120), UE1 establishes a connection with UE3 (step S122). That is, the BS corresponding to the cell in which UE1 exists and the BS corresponding to the cell in which UE3 exist allocate component carriers for establishing a dedicated line between UE1 and UE3 to UE1 and UE3, respectively.

  Subsequently, UE1 calls the UE corresponding to the next order. In this example, UE1 makes a call to UE4, which is the next call destination (step S124). An identifier indicating that the communication is multi-party communication is also added to the call from UE1 to UE4.

  UE1 judges whether there is a response from UE4 after the call to UE4 (step S130). If there is a response from UE4 (YES in step S130), UE1 establishes a connection with UE4 (step S132). That is, the BS corresponding to the cell in which UE1 exists and the BS corresponding to the cell in which UE4 exists allocate component carriers for establishing a dedicated line between UE1 and UE4 to UE1 and UE4, respectively.

  In this case, UE1 determines that it can connect to all of selected UE2 to UE4. Subsequently, UE1 notifies UE2 of identification information (telephone numbers) of UE3 and UE4, and instructs UE2 to make a call to UE3 and UE4 (step S134). And UE1 starts the telephone call between each of UE2, UE3 and UE4 (step S136).

  Furthermore, UE1 maintains a state of waiting for an incoming call from another UE so that a response from a new user can be accepted even after starting a call with UE2, UE3, and UE4 (step S190).

  On the other hand, if there is no response from UE4 (NO in step S130), UE1 can connect to UE2 and UE3 among the selected UE2 to UE4, and connection to UE4 is not possible. Judge that it is possible. Subsequently, UE1 notifies UE2 of identification information (telephone number) of UE3, and instructs UE2 to make a call to UE3 (step S138). And UE1 starts the telephone call between each of UE2 and UE3 (step S140). Furthermore, UE1 maintains the state of waiting for an incoming call from another UE so that a response from a new user can be accepted (step S190).

  If there is no response from UE3 (NO in step S120), UE1 determines that it cannot connect to UE3. Then, UE1 makes a call to UE4, which is the next call destination (step S126).

  Subsequently, after making a call to UE4, UE1 determines whether or not there is a response from UE4 (step S150). If there is a response from UE4 (YES in step S150), UE1 establishes a connection with UE4 (step S152).

  In this case, UE1 determines that it can connect to UE2 and UE4 among the selected UE2 to UE4, and cannot connect to UE3. Subsequently, UE1 notifies UE2 of identification information (telephone number) of UE4, and instructs UE2 to make a call to UE4 (step S154). And UE1 starts the telephone call between each of UE2 and UE4 (step S156). Furthermore, UE1 maintains the state of waiting for an incoming call from another UE so that a response from a new user can be accepted (step S190).

  On the other hand, when there is no response from UE4 (in the case of NO in step S150), UE1 determines that only UE2 is connectable among the selected UE2 to UE4. And UE1 starts the telephone call between UE2 (step S158). Furthermore, UE1 maintains the state of waiting for an incoming call from another UE so that a response from a new user can be accepted (step S190).

  If there is no response from UE2 (NO in step S110), UE1 determines that it cannot connect to UE2. Then, UE1 makes a call to UE3, which is the next call destination (step S116).

  Subsequently, after the call to UE3, UE1 determines whether or not there is a response from UE3 (step S160). If there is a response from UE3 (YES in step S160), UE1 establishes a connection with UE3 (step S162). That is, the BS corresponding to the cell in which UE1 exists and the BS corresponding to the cell in which UE3 exist allocate component carriers for establishing a dedicated line between UE1 and UE3 to UE1 and UE3, respectively. Then, UE1 makes a call to UE4, which is the next call destination (step S164).

  Subsequently, after making a call to UE4, UE1 determines whether or not there is a response from UE4 (step S170). If there is a response from UE4 (YES in step S170), UE1 establishes a connection with UE4 (step S172).

  In this case, UE1 determines that it can connect to UE3 and UE4 among the selected UE2 to UE4, and cannot connect to UE2. Subsequently, UE1 notifies UE3 of identification information (telephone number) of UE4, and instructs UE3 to make a call to UE4 (step S174). And UE1 starts the telephone call between each of UE3 and UE4 (step S176). Furthermore, UE1 maintains the state of waiting for an incoming call from another UE so that a response from a new user can be accepted (step S190).

  On the other hand, when there is no response from UE4 (in the case of NO in step S170), UE1 determines that only UE3 is connectable among the selected UE2 to UE4. And UE1 starts the telephone call between UE3 (step S178). Furthermore, UE1 maintains the state of waiting for an incoming call from another UE so that a response from a new user can be accepted (step S190).

  If there is no response from UE3 (NO in step S160), UE1 determines that it cannot connect to UE3. Then, UE1 makes a call to UE4, which is the next call destination (step S166).

  Subsequently, after making a call to UE4, UE1 determines whether or not there is a response from UE4 (step S180). If there is a response from UE4 (YES in step S180), UE1 establishes a connection with UE4 (step S182). At this time, UE1 judges that only UE4 is connectable among the selected UE2 to UE4. And UE1 starts the telephone call between UE4 (step S184). Furthermore, UE1 maintains the state of waiting for an incoming call from another UE so that a response from a new user can be accepted (step S190).

  On the other hand, when there is no response from UE4 (in the case of NO in step S180), UE1 determines that none of the selected UE2 to UE4 can be connected. Then, UE1 disconnects the line (step S186).

  As described above, UE1 may instruct UE2 to connect to a plurality of UEs (UE3 and UE4). At this time, UE1 determines whether or not there is a response from UE3 and UE4 in response to a request for connection to UE3 and UE4, and on the condition that there is a response from UE3 and UE4, to UE2 It instructs the connection to UE3 and UE4. Therefore, when UE1 requests a connection to UE2 to UE4, it requests a connection to UE2, and requests a connection to UE3 and UE4 after receiving a response from UE2.

(5.2: Processing procedure in UE that is not the leader)
Referring to FIG. 11, the UE that is not the lead determines whether an incoming call has been received from another UE (step S200). If no incoming call has been received (NO in step S200), the process of step S200 is repeated.

  When an incoming call is received (YES in step S200), the UE determines whether or not the received incoming call includes an identifier indicating that the communication is multi-party communication (step S202).

  When the received incoming call does not include an identifier indicating that the communication is multi-party communication (NO in step S202), the UE executes a response procedure for the received incoming call, and issues the incoming call. One-to-one communication is established with the original UE (step S206). Then, a call is started with the source UE.

  If the received incoming call includes an identifier indicating that the communication is multi-party communication (YES in step S202), the UE executes a response procedure for the received incoming call, and sends the incoming call. A connection as multi-party communication is established with the original UE (step S208). Then, a call is started with the source UE. Subsequently, the UE determines whether or not the received incoming call includes an instruction to make a call to another UE (step S210).

  When the received incoming call does not include an instruction to make a call to another UE (NO in step S210), the UE can receive an incoming call from a new user. The state waiting for an incoming call is maintained (step S212).

  If the received incoming call includes a call instruction to another UE (YES in step S210), the UE determines whether there are a plurality of call destinations instructed (step S214). .

  If there is one instructed call destination (NO in step S214), UE1 calls the instructed call destination (step S216). Thereafter, the UE waits for a response from the callee UE and establishes a connection with the callee (step S218). Then, the UE starts a call with the callee UE. As described above, any UE that is instructed as a call destination is determined to be connectable by UE1 corresponding to the leader. Therefore, basically, a response is obtained from the callee UE. Further, the UE maintains a state of waiting for an incoming call from another UE so that an incoming call from a new user can be accepted (step S212).

  On the other hand, if there are a plurality of designated call destinations (YES in step S214), UE1 calls all of the designated call destinations all at once (step S220). . Subsequently, the UE notifies identification information (telephone number) of a UE other than the UE among the designated call destinations to any one UE among the designated call destinations. At the same time, it instructs the arbitrary one UE to make a call to the other UE (step S222).

  As described above, in the communication system according to the present embodiment, it is necessary to establish a dedicated line between all combinations of two arbitrary UEs among a plurality of UEs participating in multi-party communication. The process of step S222 is a process for repeating outgoing calls hierarchically between UEs participating in multi-party communication. This process is sequentially executed according to the number of UEs participating in multi-party communication, so that dedicated lines are established for all combinations of UEs.

  Further, since it is determined that any UE instructed as a call destination can be connected by the UE 1 corresponding to the leader, basically, the process of establishing this dedicated line is not interrupted.

  Thereafter, the UE waits for a response from each UE that is a call destination, and establishes a connection with the call destination (step S224). Then, the UE starts a call with the callee UE. Further, the UE maintains a state of waiting for an incoming call from another UE so that an incoming call from a new user can be accepted (step S212).

  Multi-party communication can be realized by the UE corresponding to the leader and the other UEs performing the processes as described above.

  With this procedure, the establishment of a dedicated line between UEs in n-user communication in which n users participate can be generalized as follows. That is, UEi (1 ≦ i ≦ n) corresponding to user i makes a call to UE (i + 1) to UEn corresponding to user (i + 1) to user n, respectively. Simultaneously with this call, UE i instructs UE (i + 1) to call UE (i + 2) to UE n. By repeating this process from i = 1 to n-1, a dedicated line between the UEs can be established.

<6. Procedure for establishing a dedicated line (2)>
In the above-described procedure for establishing a dedicated line, an example in which a method in which a UE serving as a leader tries to connect sequentially to a plurality of UEs serving as participants has been shown. In this example, a process of instructing a UE having a higher priority to connect to another UE is sequentially repeated. This method has an advantage that the process can be simplified because the UE to be instructed to connect is determined in advance. On the other hand, if a response from the UE instructing the connection cannot be obtained, Processing may be interrupted.

  Therefore, a method may be adopted in which calls are made simultaneously to a plurality of users (UEs) participating in multi-party communication, and connection processing is sequentially performed in the order of quick response. According to this method, the procedure for connecting a dedicated line can be dynamically changed according to the situation of each UE.

  More specifically, the UE that is the leader makes a call to a plurality of UEs all at once, and gives an instruction to make a call to another UE to the UE that has responded earliest. When UE1 requests connection to UE2 to UE4, it requests connection to UE2 to UE4 all at once. For example, in the case of the four-party communication as described above, the leader UE1 calls the UE2, UE3, and UE4 all at once. When the BS providing the cell area in which UE1 exists receives a call including an identifier indicating that the communication is multi-party from UE1, the BS allocates different component carriers for each call to UE2, UE3, and UE4. To establish a dedicated line using carrier aggregation.

  If UE1 is the earliest responding to UE1 among UE2, UE3, and UE4 that have called all at once, after confirming the response of UE3, all other participants participating in multi-party communication Each identification information (telephone number) of UE is notified to UE3. UE3 makes a call to all UEs (in this example, UE2 and UE4) for which no dedicated line has been established with the own terminal among all other UEs participating in multi-party communication.

By repeating such a series of operations sequentially, a dedicated line between UEs is established.
That is, if UE2 is the earliest responding to UE3 among UE2 and UE4 that are simultaneously called from UE3, UE3 identifies each identification information (telephone number) of all other UEs participating in the call. ) To UE2. UE2 makes a call to all UEs (in this example, UE4) for which a dedicated line is not established with the own terminal among all other UEs participating in multi-party communication.

By such a procedure, a dedicated line is established between all users (UE).
FIG. 12 is a flowchart in the UE that takes the lead in the process of sequentially performing the connection process in the order of quick response. FIG. 13 is a flowchart in the UE other than the leader in the process of sequentially performing the connection process in the order of quick response. In addition, in the flowchart shown in FIGS. 9-11, the user 1 possessing UE1 shall become a leader and start communication between many persons.

(6.1: Processing procedure in UE as lead)
Referring to FIG. 12, user 1 operates UE1 that he / she owns to specify that multi-user communication is to be performed, and selects UE2 to UE4 which are owned by users 2 to 4 who participate in the communication (step). S302). This user selection method is performed by inputting the telephone number of the corresponding UE.

  The UE1 possessed by the user 1 makes a call to the selected UE2 to UE4 all at once (step S304). At this time, an identifier indicating the multi-party communication is added to each signal of the call from UE1 to UE2 to UE4.

  After the simultaneous call to UE2 to UE4, UE1 determines whether or not there is a response from any UE (step S306). If there is a response from any of the UEs (YES in step S306), UE1 determines which UE responded to the call earliest (step S308).

  When UE2 answers the call earliest (in the case of “UE2” in step S308), UE1 establishes a connection with UE2 (step S310). That is, the BS corresponding to the cell where UE1 exists and the BS corresponding to the cell where UE2 exists allocate component carriers for establishing a dedicated line between UE1 and UE2 to UE1 and UE2, respectively.

  Subsequently, the UE 1 identifies the identification information (telephone number) of each of the remaining UEs (UE 3 and UE 4 in this example) excluding the UE that responded to the call earliest among the plurality of UEs selected for the multi-party communication. UE2 is instructed to call UE2 (UE3 and UE4) (step S312).

  Further, UE1 sequentially establishes a connection with another UE that responded to the call subsequent to UE2 (step S314). And UE1 starts a telephone call between each of UE which established the connection (step S316).

  After that, UE1 maintains a state of waiting for an incoming call from another UE so that a response from a new user can be accepted even after starting a call with any UE (step S318).

  When UE3 answers the call earliest (in the case of “UE3” in step S308), UE1 establishes a connection with UE3 (step S320). That is, the BS corresponding to the cell in which UE1 exists and the BS corresponding to the cell in which UE3 exist allocate component carriers for establishing a dedicated line between UE1 and UE3 to UE1 and UE3, respectively.

  Subsequently, UE1 has identification information (telephone number) of each of the remaining UEs (UE2 and UE4 in this example) excluding the UE that responded to the call earliest among a plurality of UEs selected for multi-party communication. To UE3 and instructing UE3 to make a call to the UEs (UE2 and UE4) (step S322).

  Furthermore, UE1 sequentially establishes a connection with another UE that has responded to the call subsequent to UE3 (step S324). And UE1 starts a telephone call between each of UE which established the connection (step S326).

  After that, UE1 maintains a state of waiting for an incoming call from another UE so that a response from a new user can be accepted even after starting a call with any UE (step S318).

  When UE4 answers the call earliest (in the case of “UE4” in step S308), UE1 establishes a connection with UE4 (step S330). That is, the BS corresponding to the cell in which UE1 exists and the BS corresponding to the cell in which UE4 exists allocate component carriers for establishing a dedicated line between UE1 and UE4 to UE1 and UE4, respectively.

  Subsequently, UE1 has identification information (telephone number) of each of the remaining UEs (UE2 and UE3 in this example) excluding the UE that responded to the call earliest among a plurality of UEs selected for multi-party communication. To UE4 and instructing UE4 to make a call to the UEs (UE2 and UE3) (step S332).

  Further, UE1 successively establishes a connection with another UE that responded to the call subsequent to UE4 (step S334). And UE1 starts a telephone call between each of UE which established the connection (step S336).

  After that, UE1 maintains a state of waiting for an incoming call from another UE so that a response from a new user can be accepted even after starting a call with any UE (step S318).

  On the other hand, when there is no response from any UE (NO in step S306), UE1 determines that any UE among the selected UE2 to UE4 cannot be connected. Then, UE1 disconnects the line (step S340).

(6.2: Processing procedure in UE that is not the leader)
Referring to FIG. 13, a UE that is not the lead (in this example, UE2) determines whether or not an incoming call has been received from another UE (step S400). If no incoming call has been received (NO in step S400), the process of step S400 is repeated.

  When an incoming call is received (YES in step S400), UE2 determines whether or not the received incoming call includes an identifier indicating that communication is between multiple parties (step S402).

  If the received incoming call does not include an identifier indicating that the communication is multi-party communication (NO in step S402), the UE 2 executes a response procedure for the received incoming call, and sends the incoming call. One-to-one communication is established with the original UE (step S406). Then, a call is started with the source UE.

  When the received incoming call includes an identifier indicating that the communication is multi-party communication (YES in step S402), the UE 2 executes a response procedure for the received incoming call, and sends the incoming call. A connection as multi-party communication is established with the original UE (step S408). Then, a call is started with the source UE. Subsequently, UE2 determines whether or not the received incoming call includes an instruction to make a call to another UE (step S410).

  If the received incoming call does not include an instruction to make a call to another UE (NO in step S410), UE2 can receive an incoming call from a new user so that it can accept an incoming call from a new user. The state of waiting for an incoming call is maintained (step S412).

  When the received incoming call includes an instruction to make a call to another UE (YES in step S410), UE2 receives all UEs instructed to make the call (UE3 and UE4 in this example). Are simultaneously called (step S414). An identifier indicating that the communication is multi-party communication is also added to each signal related to the call.

  UE2 judges whether there is a response from any UE after a simultaneous call (step S416). If there is a response from any UE (YES in step S416), UE2 determines which UE responded to the call earliest (step S418).

  When UE3 responds to the call earliest (in the case of “UE3” in step S418), UE2 establishes a connection with UE3 (step S420). That is, the BS corresponding to the cell in which UE2 exists and the BS corresponding to the cell in which UE3 exist allocate component carriers for establishing a dedicated line between UE2 and UE3 to UE2 and UE3, respectively.

  Subsequently, UE2 sends the identification information (telephone number) of the remaining UEs (UE4 in this example) to the UE3 except for the UE that responded to the call earliest among the plurality of UEs selected for the multi-party communication. In addition, the UE 3 is instructed to make a call to the UE (UE 4) (step S422).

  Further, UE2 sequentially establishes a connection with another UE that has responded to the call subsequent to UE3 (step S424). And UE2 starts a telephone call between each of UE which established the connection (step S426).

  Thereafter, the UE 2 maintains a state of waiting for an incoming call from another UE so that an incoming call from a new user can be accepted (step S412).

  On the other hand, when UE4 responds to the call earliest (in the case of “UE4” in step S418), UE2 establishes a connection with UE4 (step S430). That is, the BS corresponding to the cell in which UE2 exists and the BS corresponding to the cell in which UE4 exists allocate component carriers for establishing a dedicated line between UE2 and UE4 to UE2 and UE4, respectively.

  Subsequently, UE2 sends the identification information (telephone number) of the remaining UEs (UE3 in this example) other than the UE that responded to the call earliestly among the plurality of UEs selected for the multi-party communication to UE4. In addition, the UE 4 is instructed to make a call to the UE (UE 3) (step S432).

  Further, UE2 sequentially establishes a connection with another UE that responded to the call subsequent to UE4 (step S434). And UE2 starts a telephone call between each of UE which established the connection (step S436).

  Thereafter, the UE 2 maintains a state of waiting for an incoming call from another UE so that an incoming call from a new user can be accepted (step S412).

  On the other hand, when there is no response from any of the UEs (NO in step S416), the above process is skipped and the process of step S412 is executed.

<7. Modification>
In the above-described embodiment, the example in which the UE 100 and the BS 200 mainly execute the establishment process of the line related to the multi-party communication has been described. However, the MME 300 may execute at least a part of these processes. . Furthermore, you may provide another main body for performing the connection process which concerns on communication between many persons.

  As described above, the main body that executes the process related to multi-party communication according to the present embodiment may be present in any one of the communication systems, and the implementation form includes a system scale, a system hierarchy configuration, a network configuration, It is possible to design appropriately according to various situations such as the cooperation form of other systems.

<8. Advantage>
As described above, in the communication system according to the present embodiment, when multi-party communication is performed, a dedicated line is established for each user (wireless terminal) without installing a server. Communication between persons can be realized in real time with almost no delay. Thus, optimal communication control can be selected between users by allocating component carriers using carrier aggregation.

  As described above, since it is not necessary to perform a voice data synthesis process between users participating in multi-person communication without installing a server, the processing load on the MME is not increased. As a result, a delay due to processing in the MME does not occur.

  By using carrier aggregation as described above, resource blocks can be allocated over a plurality of bands.

  In addition, by using carrier aggregation, component carriers are allocated to dedicated lines between users, so that communication can be performed while occupying the allocated bandwidth between users. In this way, since the allocated bandwidth can be monopolized, it is possible to achieve the required throughput for each call between users and to perform optimal communication control (modulation scheme or MIMO scheme) according to the terminal capability. it can. Thereby, radio resources can be used effectively.

  Further, in the communication system according to the present embodiment, since component carriers are allocated for each dedicated line corresponding to users, there is a case where there is an increase or decrease (addition or deletion) of users participating in multi-party communication. However, since communication control can be performed on a component carrier basis, participants can be added or deleted more flexibly.

<9. Other aspects>
A communication method according to an aspect of the present invention includes several preferred forms as follows.

  Preferably, the first wireless terminal sends data to the second and third wireless terminals independently via the first and second connections, respectively, and independently via the first and second connections. The data received from the second and third wireless terminals is combined and output.

  Preferably, in the communication method, the base station corresponding to the third wireless terminal has a fifth connection associated with the communication between the third wireless terminal and the first wireless terminal, the third wireless terminal, Further comprising establishing a sixth connection of a different frequency than the fifth connection associated with the communication with the two wireless terminals.

  Preferably, in the communication method, the base station corresponding to the first wireless terminal and the base station corresponding to the second wireless terminal have substantially the transmission performance between the first connection and the third connection. It further includes the step of controlling to match.

  Preferably, the communication method further includes a step in which the first wireless terminal determines whether or not there is a response from the third wireless terminal to the request for connection to the third wireless terminal, The step of instructing the second wireless terminal to connect to the third wireless terminal is executed on condition that there is a response from the third wireless terminal.

  Preferably, the step of instructing the second wireless terminal to connect to the third wireless terminal includes the step of instructing connection to the plurality of third wireless terminals.

  Preferably, the step of the first wireless terminal requesting connection to the second and third wireless terminals includes a step of requesting connection to the second wireless terminal and a response from the second wireless terminal. And requesting a connection to the third wireless terminal.

  Preferably, the step in which the first wireless terminal requests connection to the second and third wireless terminals includes the step of simultaneously requesting connection to the second and third wireless terminals.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Communication system, 100 Radio | wireless terminal (UE), 102,210 Signal processing part, 104,202 Control part, 105,205 Interpersonal communication logic, 112,212 Transmission part, 114,214 Transmission antenna, 116,216 Reception part, 118, 218 receiving antenna, 150 housing, 152 display unit, 154 microphone, 156 speaker, 158 input unit, 200 base station (BS), 204 central processing unit, 206 host network interface, 208 control interface, 300 mobile management device ( MME), 400 core network.

Claims (4)

A communication method for performing multi-party communication between a plurality of wireless terminals,
A first wireless terminal requesting connection to a second and third wireless terminal;
A base station corresponding to the first wireless terminal; a first connection associated with communication between the first wireless terminal and the second wireless terminal; a first wireless terminal and the third wireless terminal; Establishing a second connection of a different frequency than the first connection associated with communication with a wireless terminal;
The first wireless terminal instructing the second wireless terminal to connect to the third wireless terminal;
The second wireless terminal requesting a connection to the third wireless terminal in response to an instruction from the first wireless terminal;
A base station corresponding to the second wireless terminal, a third connection associated with the communication between the second wireless terminal and the first wireless terminal, the second wireless terminal and the third wireless terminal; Establishing a fourth connection having a frequency different from that of the third connection associated with the communication with the wireless terminal. A communication system for performing multi-party communication,
Multiple wireless terminals,
A plurality of base stations providing a predetermined cell area,
The wireless terminal is
Means for requesting connection to a plurality of wireless terminals;
Means for instructing one of the plurality of wireless terminals that requested the connection to connect to the remaining wireless terminals;
Means for requesting connection to the indicated wireless terminal in response to an instruction to connect to any wireless terminal;
The base station
A communication system comprising means for establishing a plurality of connections having different frequencies from each other in response to a connection request from a wireless terminal existing in a cell area provided by the base station to a plurality of wireless terminals. A wireless terminal capable of multi-party communication,
Means for requesting connection to a plurality of other wireless terminals, and a base station that provides a cell area in which the wireless terminal is present responds to a connection request to the plurality of wireless terminals, Establish each connection,
Means for instructing one of the plurality of wireless terminals that requested the connection to connect to the remaining wireless terminals;
Means for requesting connection to the instructed wireless terminal in response to an instruction to connect to any of the wireless terminals. A base station capable of multi-party communication,
A base station comprising means for establishing a plurality of connections having different frequencies from each other in response to a connection request from a wireless terminal present in a cell area to be provided to the plurality of wireless terminals.

Images