JP2008199676A - Communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform efficient and flexible group communication control. <P>SOLUTION: A downlink frame generation means 11 adds a time slot for broadcasting notification to a frame constituted of a header part and n time slots assigned to each terminating unit when performing ordinary communication, and generates a downlink frame by inserting a broadcasting notification data into the time slot for broadcasting notification. An uplink frame generation means 21 adds a time slot for broadcasting notification response to a frame constituted of a header part and a time slot assigned to the self, and generates an uplink frame by inserting broadcasting notification response data, which is response data to the broadcasting notification data, into the time slot for broadcasting notification response. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a communication system relates especially communication system for performing communication with the station side and the subscriber side.

  In recent years, communication services have been diversified, and demand for video-on-demand, CATV, high-speed computer communication, and the like has increased. Development of a subscriber access communication system for directly connecting a station having such a database and a subscriber's home is in progress.

  FIG. 17 is a diagram showing a configuration of a subscriber access communication system. Terminating devices 70-1 to 70-n are arranged in the subscriber homes 700-1 to 700-n, and a terminal device 60 is arranged in the station 600.

The terminal devices 70-1 to 70-n are connected to telephones, TVs, personal computers, and the like, and the terminal devices 70-1 to 70-n and the terminal device 60 are connected to the branch unit 30 through the transmission medium.
Downlink information (downlink frames) from the station 600 to the subscriber homes 700-1 to 700-n is transmitted from one transmission line via the branching unit 30 through a transmission path branched in a dendritic manner.

  Further, uplink information (upstream frames) from the subscriber homes 700-1 to 700-n to the station 600 is transmitted from the transmission path branched in a dendritic manner through the branching unit 30 to a single transmission path. Sent.

  In the conventional subscriber access communication system as described above, when the terminal device 60 generates a downlink frame for broadcast, the same number of data as the terminal device to be communicated is copied. Then, the copied data is stored in a pre-assigned time slot corresponding to each terminal device, and a downlink frame is generated and transmitted.

  FIG. 18 is a diagram showing an outline of data copy processing. In the downstream frame, time slots corresponding to the number of terminal devices to be communicated are allocated. Terminating devices 70-1 to 70-n and time slots TS1 to TSn correspond to each other. When transmitting a downstream frame, n copies of data are taken and stored in each time slot.

  As described above, when a downlink frame for broadcast is created and transmitted, conventionally, there has been a problem that the same number of data as the terminal devices in the group must be copied and set, so that the efficiency is low.

  Further, when the terminal devices 70-1 to 70-n are communicated in groups, there has been a problem in the past that flexible group communication control is not considered for group communication.

  The present invention has been made in view of these points, and an object thereof is to provide a communication system that performs flexible and efficient communication control.

In order to solve the above-described problems, a communication system that performs communication between a station side and a subscriber side is provided. This communication system includes a terminal device comprising downlink frame generating means for generating a downlink frame, station side communication control means for performing transmission processing of the downlink frame and reception processing of the uplink frame, and the uplink frame. N terminal devices composed of uplink frame generating means for generating and subscriber-side communication control means for performing transmission processing of the upstream frame and reception processing of the downstream frame, the terminal device, and the terminal device In contrast, a branching unit connected by a 1: n transmission line is provided.

  Here, one terminal device is a terminal device # 0, n terminal devices are terminal devices # 1 to #n, all terminal devices # 1 to #n are grouped, and the terminal device # When one broadcast notification is sent from 0 to the terminal devices # 1 to #n, the downlink frame generating means performs overhead that is control information and normal communication assigned to each of the terminal devices # 1 to #n. A broadcast notification time slot is newly added to a frame consisting of n time slots, and broadcast notification data is inserted into the broadcast notification time slot to generate a downlink frame for communication on the station side. The control means transmits the downstream frame to the terminal devices # 1 to #n, and the upstream frame generating means in the terminal devices # 1 to #n performs the overhead and the frame consisting of the time slot allocated to itself. Broadcast notification A response time slot is newly added, and broadcast notification response data, which is individual response data of the terminal devices # 1 to #n for the broadcast notification data, is inserted into the broadcast notification response time slot, and the uplink frame is transmitted. The subscriber-side communication control means in the terminating devices # 1 to #n transmits the uplink frame to the terminal device.

  Further, when the terminal devices # 1 to #n are divided into a plurality of groups and the group communication type unit divided into a plurality of groups is notified from the terminal device # 0 of each group, When one of the divided groups is a group g1, the downlink frame generation means is a frame composed of n time slots for performing normal communication assigned to the overhead and the terminal devices # 1 to #n. On the other hand, a time slot for group communication type and a time slot for broadcast notification are newly added, and the same identifier is inserted into the time slot for group communication type for the terminating device included in the group g1. The broadcast notification data of the same content is inserted into the broadcast notification time slot of the terminating device in the group g1 to generate a downlink frame, and the station side communication control unit Transmits the downstream frame to the terminal devices # 1 to #n, and each of the upstream frame generation means in the terminal device included in the group g1 starts from the time slot when performing normal communication assigned to itself with the overhead. Group communication response type time slot and broadcast notification response time slot are newly added, and the same identifier as the received group communication type time slot is assigned to the group communication response type time slot. The broadcast notification response time slot is inserted with the broadcast notification response data, which is the response data of each terminal device in the group g1, with respect to the broadcast notification data, and an uplink frame is generated. Each of the subscriber side communication control means in the included termination device transmits an upstream frame to the terminal device.

Communication system was configured to perform group communication control generates a downlink frame and an uplink frame for group communication. As a result, when performing group communication, it is not necessary to copy the same number of data as the end devices in the group as in the conventional case, so that the processing is simplified and efficient and flexible group communication control is performed. Is possible.

  These and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments by way of example of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a principle diagram of a communication system. The communication system 1 includes a terminal device 10 disposed in a station 100 and terminal devices 20-1 to 20-n disposed in subscriber homes 200-1 to 200-n. Communication with subscriber homes 200-1 to 200-n is performed.

  The terminal devices 20-1 to 20-n are connected to telephones, TVs, personal computers, etc. (not shown), and the terminal device 10 and the terminal devices 20-1 to 20-n are connected to the optical fiber cable via the branch unit 3. And so on through a transmission medium.

  Further, the communication system 1 can set group communication. The group communication referred to in the present invention means communication in which the terminal devices 20-1 to 20-n are divided into groups and broadcast notification is performed from the terminal device 10 to the terminal devices in the divided group. .

  For example, if the termination devices 20-1 and 20-2 are one group G1, and the termination devices 20-3 to 20-n are one group G2, the termination devices 20-1 and 20-2 and the terminal device 10 Communication can be performed within the closed group G1. Further, communication can be performed within the group G2 closed between the terminal devices 20-3 to 20-n and the terminal device 10. Further, all of the termination devices 20-1 to 20-n may be made into one group.

  For the terminal device 10, the downlink frame generation means 11 provides a group communication time slot and generates a downlink frame for group communication. The configuration of the downstream frame will be described later. The station-side group communication control means 12 performs group communication control by performing transmission processing of downlink frames and reception processing of uplink frames transmitted from the terminal devices 20-1 to 20-n.

  For the termination devices 20-1 to 20-n, the uplink frame generation means 21 generates an uplink frame. The configuration of the upstream frame will be described later. The subscriber-side group communication control means 22 performs upstream frame transmission processing and downstream frame reception processing to perform group communication control.

  Next, a first embodiment of the communication system 1 will be described. FIG. 2 is a diagram showing the structure of the downstream frame. The downstream frame 40-1 includes a header part 41 and a data part 42. The header 41 is set with overhead as control information.

A number of time slots TS1 to TSn that can accommodate the terminal devices 20-1 to 20-n are allocated to the data unit 42, and the terminal devices 20-1 to 20-n and the time slots TS1 to TSn correspond to each other. . A group communication time slot GTS (corresponding to a broadcast notification time slot) is a time slot used when a broadcast notification is sent from the terminal station device 10 to a plurality of terminal devices in the group.

  FIG. 3 is a diagram showing the configuration of the upstream frame. The upstream frame 50-1 includes a header part 51 and a data part 52. The header 51 is set with overhead as control information.

The data section 52 is assigned a time slot for each terminal device, and the group communication response time slot GTSa (corresponding to the broadcast notification response time slot) is a time slot used for the response of the group communication time slot GTS. It is.

  FIG. 4 is a diagram showing the configuration of the terminal device. The terminal device 10a according to the first embodiment includes a downlink frame generation unit 11-1 and a station side group communication control unit 12. The downlink frame generation unit 11-1 includes a station side communication table management unit 11a-1 and a downlink frame assembly unit 11b.

  The station side communication table management unit 11a-1 manages the station side communication table T1. The station side communication table T1 includes a group number and a group communication time slot number. In the figure, the group number is G1, and the group communication time slot number is 10.

The downlink frame assembling unit 11b assembles a downlink frame for group communication with reference to the station side communication table T1. In this case, the time slot position of time slot number 10 is recognized as a group communication time slot, and notification data (corresponding to broadcast notification data) is stored in this time slot position. The station-side group communication control means 12 transmits the downlink frame generated by the downlink frame generation means 11-1.

  FIG. 5 is a diagram showing the configuration of the termination device. The terminating device 20a according to the first embodiment includes an upstream frame generation means 21-1 and a subscriber side group communication control means 22. The upstream frame generation means 21-1 includes a subscriber side communication table management means 21a-1 and an upstream frame assembly means 21b.

  The subscriber side communication table management means 21a-1 manages the subscriber side communication table t1. The subscriber-side communication table t1 includes a termination device number, a time slot number (time slot number assigned to itself), and a group communication response time slot number. In the figure, the terminating device number is 20-1, the time slot number is 1, and the group communication response time slot number is 2.

The upstream frame assembling means 21b refers to the subscriber side communication table t1 and assembles an upstream frame for group communication. In this case, the time slot position of time slot number 2 is recognized as a group communication response time slot, and response data (corresponding to broadcast notification response data) is stored in this time slot position. The subscriber side group communication control means 22 transmits the uplink frame generated by the uplink frame generation means 21-1.

  As described above, in the communication system according to the first embodiment, group communication time slots are provided to generate downlink frames, group communication response time slots are provided to generate uplink frames, and group communication control is performed. It was set as the structure which performs.

  As a result, when performing grouping, it is not necessary to copy the same number of data as the terminal devices in the group as in the prior art, so the processing is simplified and efficient group communication control can be performed. .

  Further, in the above, the uplink frame provided with the group communication response time slot is transmitted from the terminal device 20a. However, if the broadcast notification is sent from the terminal device 10a that does not require a response, the group communication response time slot is set. It is not necessary to set the uplink frame.

  Next, a second embodiment of the communication system 1 will be described. The second embodiment is group communication control when the terminal devices 20-1 to 20-n are divided into a plurality of groups and group communication is performed simultaneously.

FIG. 6 is a diagram showing the structure of the downstream frame. The downstream frame 40-2 includes a header part 41a and a data part 42. The header 41a is set with the overhead and the group communication type 43 (corresponding to the group communication type time slot) as control information.

  The group communication type 43 is specifically a group identifier for identifying a group. For example, when there are two groups, if the group identifiers are A and B, the terminal station device transmits a downlink frame in which A is set in the group communication type 43 and a downlink frame in which B is set in the group communication type 43. This makes it possible to communicate with the two groups.

FIG. 7 is a diagram showing the configuration of the upstream frame. The upstream frame 50-2 includes a header part 51a and a data part 52. The header 51a is set with the control information overhead and the group communication response type 53 (corresponding to the group communication response type time slot) .

The group communication response type 53 is a group identifier of the group to which the group belongs, and corresponds to the same group identifier as the group communication type 43.
FIG. 8 is a diagram showing the configuration of the terminal device. The terminal device 10b according to the second embodiment includes a downlink frame generation unit 11-2 and a station side group communication control unit 12. The downlink frame generation unit 11-2 includes a station side communication table management unit 11a-2 and a downlink frame assembly unit 11b.

The station side communication table management unit 11a-2 manages the station side communication table T2. The station side communication table T2 includes a group number, a group communication time slot number (corresponding to a broadcast notification time slot number), and a group communication type. In the figure, three groups are set. For example, as one group, the group number is G1, the group communication time slot number is 10, and the group communication type is A.

  The downlink frame assembling unit 11b assembles a downlink frame for group communication with reference to the station side communication table T2. In this case, for downlink frames transmitted to the group G1, the notification data addressed to the group G1 is stored in the time slot position of A and the time slot number 10 for the group communication type 43.

  Further, for downlink frames transmitted to the group G2, the notification data addressed to the group G2 is stored in the time slot position of the time slot number 10 and B in the group communication type 43.

  Furthermore, for downlink frames transmitted to the group G3, C is stored in the group communication type 43, and notification data addressed to the group G3 is stored in the time slot position of the time slot number 10. The station side group communication control means 12 transmits these downlink frames generated by the downlink frame generation means 11-2.

  FIG. 9 is a diagram showing the configuration of the termination device. The terminating device 20b according to the second embodiment includes an upstream frame generation unit 21-2 and a subscriber side group communication control unit 22. The upstream frame generation means 21-2 includes a subscriber side communication table management means 21a-2 and an upstream frame assembly means 21b.

The subscriber side communication table management means 21a-2 manages the subscriber side communication table t2. The subscriber side communication table t2 includes a terminating device number, a time slot number (time slot number assigned to itself), a time slot number for group communication response (corresponding to a time slot number for broadcast notification response), and a group communication response. Consists of types. In the figure, the terminal device number is 20-1, the time slot number is 1, the group communication response time slot number is 2, and the group communication response type is A.

  The upstream frame assembling means 21b refers to the subscriber side communication table t2 and assembles an upstream frame for group communication. In this case, the response data is stored at the position of the time slot for group communication response of A and time slot number 2 in the group communication response type 53. The subscriber side group communication control means 22 transmits the uplink frame generated by the uplink frame generation means 21-2.

  As described above, the communication system according to the second embodiment is configured to perform group communication control by providing the group communication type 43 in the downstream frame and the group communication response type 53 in the upstream frame. Thereby, a plurality of group communications can be performed efficiently, and the flexibility of the group communications control can be increased.

Next, a third embodiment of the communication system 1 will be described. The third embodiment is a case where a plurality of group communication time slots are further provided to the second embodiment.
FIG. 10 is a diagram showing the structure of the downstream frame. The downstream frame 40-3 includes a header part 41a and a data part 42a. A plurality of group communication time slots GTS1 to GTSm are allocated to the data part 42a. Thus, by setting a plurality of group communication time slots for one group, the flexibility of group communication control can be further increased.

  FIG. 11 is a diagram illustrating a configuration of an uplink frame. The upstream frame 50-3 includes a header part 51a and a data part 52a. A plurality of group communication response time slots GTSa-1 to GTSa-m are allocated to the data portion 52a.

  FIG. 12 is a diagram showing the configuration of the terminal station device. The terminal device 10c according to the third embodiment includes a downlink frame generation unit 11-3 and a station side group communication control unit 12. The downlink frame generation unit 11-3 includes a station side communication table management unit 11a-3 and a downlink frame assembly unit 11b.

  The station side communication table management unit 11a-3 manages the station side communication table T3. The station side communication table T3 includes a group number, a group communication time slot number, and a group communication type. In the figure, three groups are set. For example, as one group, the group number is G1, the group communication time slot numbers are 10, 11, 12, and the group communication type is A.

  The downlink frame assembling unit 11b refers to the station side communication table T3 to assemble a downlink frame for group communication. In this case, for downlink frames transmitted to the group G1, the notification data addressed to the group G1 is stored at the time slot positions of A and time slot numbers 10, 11, and 12 in the group communication type 43.

  For downlink frames transmitted to the group G2, the notification data addressed to the group G2 is stored in the time slot positions of B and time slot numbers 13, 14, and 15 in the group communication type 43.

  Further, for downlink frames transmitted to the group G3, the notification data addressed to the group G3 is stored in the time slot positions of C and time slot numbers 16, 17, and 18 in the group communication type 43. The station side group communication control means 12 transmits the downlink frame generated by the downlink frame generation means 11-3.

  FIG. 13 is a diagram showing the configuration of the termination device. The terminating device 20c of the third embodiment is composed of an uplink frame generation means 21-3 and a subscriber side group communication control means 22. The upstream frame generation unit 21-3 includes a subscriber side communication table management unit 21a-3 and an upstream frame assembly unit 21b.

  The subscriber side communication table management means 21a-3 manages the subscriber side communication table t3. The subscriber-side communication table t3 includes a termination device number, a time slot number (a time slot number assigned to itself), a group communication response time slot number, and a group communication response type. In the figure, the terminating device number is 20-1, the time slot number is 1, the group communication response time slot number is 2, 3, and 4 and the group communication response type is A.

  The upstream frame assembling means 21b refers to the subscriber side communication table t3 and assembles an upstream frame for group communication. In this case, the response data is stored in the time slot positions of A and group communication response time slot numbers 2, 3, and 4 in the group communication response type 53. The subscriber-side group communication control means 22 transmits the uplink frame generated by the uplink frame generation means 21-3.

  As described above, the communication system of the third embodiment is configured to have a plurality of group communication time slots and group communication response time slots. Thereby, a plurality of group communications can be performed efficiently, and the flexibility of the group communications control can be increased.

  Next, a modification of the upstream frame will be described. FIG. 14 is a diagram illustrating a modification of the upstream frame. The upstream frame generation means 21 generates the upstream frame 50-4 when normal communication is not performed.

  The upstream frame 50-4 includes a header part 51a and a data part 52b. An overhead and a group communication response type 53 are added to the header portion 51a, and its own time slot is deleted from the data portion 52b to make only the group communication response time slot GTSa-1. Thus, efficient group communication control can be performed by omitting unnecessary time slots.

FIG. 15 is a diagram illustrating a modified example of the upstream frame. The uplink frame generation means 21 generates an uplink frame 50-5 when a communication request is made from the terminal devices 20-1 to 20-n.
The upstream frame 50-5 includes a header part 51b and a data part 52c. Overhead and group communication request 54 are added to the header portion 51b, and a group communication request time slot 55 is added to the data portion 52c. The group communication request 54 describes information on whether or not to perform group communication, and the group communication request time slot 55 describes information necessary for group communication (for group communication request 54 and group communication request). Time slot 55 corresponds to group communication request information) . As a result, group communication requests can be made to the terminal device 10 from the terminal devices 20-1 to 20-n, so that flexible group communication control is possible.

Next, a communication method is generated. FIG. 16 is a flowchart showing the processing procedure of the communication method.
[S1] The host device provides a time slot for group communication, and generates and transmits a downlink frame for group communication.
[S2] The subordinate apparatus receives and processes the downstream frame.
[S3] The subordinate apparatus generates and transmits an uplink frame for group communication response.
[S4] The host device receives and processes the upstream frame. Then, group communication control is performed between the upper device and the lower device.

Here, the group communication type is added when the downlink frame is generated. Further, when generating an uplink frame, a group communication response time slot and a group communication response type are added.
Furthermore, if it is not necessary to perform normal communication for the uplink frame, the data part may generate and transmit an uplink frame composed only of a group communication response time slot. Furthermore, the group communication request and the group communication request time slot may be added to the upstream frame, and the group communication request may be made from the lower apparatus to the upper apparatus.

  In addition, since the group communication type and the group communication response type are provided, a plurality of group communications can be realized simultaneously. Further, since the group communication request is set in the upstream frame, it becomes possible to request group communication from the terminal devices 20-1 to 20-n.

  In the above description, a general system that performs group communication has been described. However, the present invention can be applied to any system that can perform broadcast communication. For example, the present invention is also applicable to a case in which broadcast communication is performed in an optical access communication system such as wireless communication, LAN, or ATM-PON (Asynchronous Transfer Mode-Passive Optical Network) as a system that performs 1-to-N communication. It is possible to apply.

  The above merely illustrates the principle of the present invention. In addition, many modifications and changes can be made by those skilled in the art, and the present invention is not limited to the precise configuration and application shown and described above, and all corresponding modifications and equivalents may be And the equivalents thereof are considered to be within the scope of the invention.

1 is a principle diagram of a communication system. It is a figure which shows the structure of a downstream frame. It is a figure which shows the structure of an upstream frame. It is a figure which shows the structure of a terminal device. It is a figure which shows the structure of a termination | terminus apparatus. It is a figure which shows the structure of a downstream frame. It is a figure which shows the structure of an upstream frame. It is a figure which shows the structure of a terminal device. It is a figure which shows the structure of a termination | terminus apparatus. It is a figure which shows the structure of a downstream frame. It is a figure which shows the structure of an upstream frame. It is a figure which shows the structure of a terminal device. It is a figure which shows the structure of a termination | terminus apparatus. It is a figure which shows the modification of an upstream frame. It is a figure which shows the modification of an upstream frame. It is a flowchart which shows the process sequence of a communication method. It is a figure which shows the structure of a subscriber access communication system. It is a figure which shows the outline | summary of the copy process of data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication system 100 Station 10 End station apparatus 11 Downstream frame production | generation means 12 Station side group communication control means 3 Branch part 200-1 to 200-n Subscriber house 20-1 to 20-n Termination apparatus 21 Upstream frame production means 22 Subscription Group communication control means G1, G2 group

Claims (5)

In a communication system in which communication is performed between the station side and the subscriber side,
A terminal device comprising downlink frame generating means for generating a downlink frame, and station-side communication control means for performing transmission processing of the downlink frame and reception processing of the uplink frame;
N terminating devices each comprising an upstream frame generating means for generating the upstream frame, and a subscriber-side communication control means for performing the upstream frame transmission process and the downstream frame reception process;
A branching unit connected to the terminal device and the terminal device via a transmission line of 1: n;
With
One terminal device is a terminal device # 0, n terminal devices are terminal devices # 1 to #n,
When all the terminal devices # 1 to #n are grouped into one group, one broadcast notification is sent from the terminal device # 0 to the terminal devices # 1 to #n.
The downlink frame generation means is used for broadcast notification with respect to an overhead as control information and a frame composed of n time slots when performing normal communication assigned to each of the terminal devices # 1 to #n. A new time slot is added, and broadcast notification data is inserted into the broadcast notification time slot to generate the downlink frame,
The station side communication control means transmits the downlink frame to the terminal devices # 1 to #n,
The uplink frame generation means in the termination devices # 1 to #n newly adds a broadcast notification response time slot to a frame composed of overhead and a time slot allocated to itself. Inserting broadcast notification response data, which is individual response data of the terminal devices # 1 to #n for the broadcast notification data, into the notification response time slot, and generating the uplink frame,
The subscriber side communication control means in the terminal devices # 1 to #n transmits the uplink frame to the terminal device,
In the case where the terminal devices # 1 to #n are divided into a plurality of groups, and the group communication type unit divided into a plurality of groups performs broadcast notification of each group from the terminal device # 0. If one of the divided groups is group g1,
The downlink frame generation means includes a group communication type time slot for a frame consisting of n time slots when performing normal communication assigned to the overhead and the terminal devices # 1 to #n, A broadcast notification time slot is newly added, and the same identifier is inserted into the group communication type time slot for the termination device included in the group g1, and the termination device in the group g1 is inserted. Inserting the broadcast notification data having the same contents into the broadcast notification time slot, and generating the downlink frame,
The station side communication control means transmits the downlink frame to the terminal devices # 1 to #n,
Each of the uplink frame generation means in the terminating device included in the group g1 is configured to receive a group communication response type time slot for a frame consisting of a time slot for normal communication assigned to the overhead and itself. And a broadcast notification response time slot, and the same identifier as the received group communication type time slot is inserted into the group communication response type time slot. In the slot, broadcast notification response data, which is response data of each of the terminating devices in the group g1, is inserted into the broadcast notification data, and the uplink frame is generated,
Each of the subscriber side communication control means in the terminating device included in the group g1 transmits the uplink frame to the terminal device.
A communication system characterized by the above. 2. The communication system according to claim 1, wherein the downlink frame generating means manages a station side communication table for registering items of a group number, a broadcast notification time slot number, and a group communication type . 2. The uplink frame generation means manages a subscriber side communication table for registering each item of a terminal device number, a time slot number, a broadcast notification response time slot number, and a group communication response type. The communication system described. 2. The communication system according to claim 1, wherein the downlink frame generating means adds an arbitrary number of broadcast notification time slots necessary for broadcast notification according to each group. When the terminating device not included in the group g1 participates in the group g1, information indicating that the uplink frame generation means in the terminating device not included in the group g1 should participate in the group g1 The communication system according to claim 1, wherein the uplink frame to which the group communication request information describing is added is generated.

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