JP7111451B2 - Wireless communication system and relay device - Google Patents

Description

The present invention relates to wireless communication systems, and more particularly to group communication.

The ARIB STD-T79 standard has been proposed as a TDMA system for digital wireless communication systems. This radio communication system is a disaster prevention radio communication system, and there are two types of communication methods: base station communication in which communication is performed via a base station, and direct communication between mobile stations without via a base station. In addition, a relay station (direct communication relay station) is used as a wireless device to connect a terminal (mobile station) within the base station communication area in base station communication and a terminal (mobile station) in the direct communication area in direct communication between mobile stations. ) is provided.

FIG. 1 shows the configuration of a radio communication system. A wireless communication system includes a base station BSA, a plurality of mobile stations T1 and T2 within the communication area of the base station BSA, and a relay station 1A. The dedicated machine 10A and the dedicated machine 20A for direct communication for performing group communication with the direct communication mobile stations A and A2 in areas where the base station BSA is out of communication range, and the dedicated machine 10A via the base station and the dedicated machine 20A for direct communication are connected. It has a dedicated cable CA1 for The wireless communication system is also provided with a base station BSB, which is connected via a line controller C to a base station BSA. The base station BSB has a plurality of mobile stations T3 and T4 within the communication area of the base station BSB and a relay station 1B. , a dedicated direct communication device 20B for performing group communication with the direct communication mobile stations B and B2 in an area where the base station BSB is out of the communication range, and a dedicated cable CA2 connecting the dedicated device 10B via the base station and the dedicated direct communication device 20B. It has

FIG. 2 is a diagram for explaining the communication state of group communication when direct communication mobile station A communicates with direct communication mobile station B in FIG.

When direct communication mobile station A communicates with direct communication mobile station B, direct communication mobile station A communicates with direct communication mobile station B via relay station 1A, base station BSA, circuit controller C, base station BSB and relay station 1B. Communicate with station B.

First, the direct communication mobile station A transmits a synchronization burst (SB) a specified number of times, for example, five times, to the relay station 1A for synchronization probability, and then transmits voice over the traffic channel TCH. The relay station 1A sends a speech request SB2 to the base station BSA, and the base station BSA sends a speech approval SB3 to the relay station 1A in response to the speech request SB2. The base station BSA sends a speech acknowledgment SB4 in response to receiving the speech acknowledgment SB3, and the base station BSA sends a traffic channel TCH to the relay station 1A to establish synchronization. After that, the relay station 1A sends voice to the base station BSA on the traffic channel TCH. The traffic channel TCH transmitted from the relay station 1A is sent to the line controller C and the base station BSB. The base station BSB transmits a traffic channel TCH (B/I=I) indicating idle and a traffic channel TCH (B/I=B) indicating busy to the relay station 1B. Relay station 1B then transmits synchronization bursts (SB) to direct communication mobile station B a specified number of times, for example, five times, in order to establish synchronization with direct communication mobile station B, and then transmits voice over traffic channel TCH. Send to direct communication mobile station B.

Thus, when direct communication mobile station A communicates with direct communication mobile station B, the following delays occur as shown in the figure.
1: Processing delay of relay station 1A.
2: Delay for establishing synchronization between relay station 1A and base station BSA.
3: Infrastructure delay due to line controller C;
4: Processing delay of relay station 1B.
5: Delay for establishing synchronization between relay station 1B and direct communication mobile station B;

Therefore, when a terminal (mobile station A) in the direct communication area acquires the right to transmit, there is a delay before each device recognizes that it has acquired the right to transmit. There's a problem.

FIG. 3 is a diagram for explaining the communication state of group communication in FIG. 1 when the base communication mobile station T3 has acquired the transmission right before the direct communication mobile station A attempts to acquire the transmission right. is.

First, base communication mobile station T3 exchanges speech request SB2, speech approval SB3, speech acceptance SB4 and traffic channel TCH with base station BSB to acquire the transmission right. Station T3 sends voice on traffic channel TCH to base station BSB. A traffic channel TCH generated by the base communication mobile station T3 is transmitted to the line controller C, the base station BSA, and the base side mobile station A. On the other hand, the direct-side mobile station A also similarly transmits a synchronization burst (SB) a specified number of times, for example, five times, to the direct-side mobile station A2 and the relay station 1A for establishing synchronization, and then outputs voice. Sent on the traffic channel TCH.

In this case, since the base-side mobile station T3 has already acquired the transmission right, the relay station BSA cannot acquire the transmission right. As a result, the voice of the direct side mobile station A does not reach the base side (base side mobile station T1). Also, since the direct side mobile station A cannot determine whether or not it has acquired the transmission right, it will continue transmission. As a result, the voice of base side mobile station A does not reach the direct side (direct communication mobile station A2). Furthermore, the voice of the base station BSB does not reach the direct communication mobile station A and the direct communication mobile station A2 under the control of the relay station 1A.

Therefore, when the mobile station of direct communication tries to acquire the right to transmit, if the mobile station of base communication acquires the right to transmit first, they will be in a state of transmitting. Therefore, there is a problem that the call cannot be heard at some points.

For example, Japanese Patent Laid-Open No. 2010-114741 (Patent Document 1) is a proposal regarding a relay station of a wireless communication system.

JP 2010-114741 A

An object of the present disclosure is to propose a technology capable of avoiding audio cutoff at the beginning (first) of a call and collision of transmission rights.
Other problems and novel features will become apparent from the description of the specification and the accompanying drawings.

A brief outline of a representative one of the present disclosure is as follows.
That is, a wireless communication system includes a base station, multiple mobile stations, and a relay station. The relay station includes a base station-routed radio for performing group communication with the base station, and a direct communication radio for performing group communication with the mobile station in an area where the base station is out of communication range. . A direct communication radio manages the transmission rights of the mobile station.

According to the above, by managing the transmission rights of the mobile stations under the control of the base station-routed dedicated machine, it is possible to avoid voice loss and transmission right collision at the beginning of a call.

1 is a diagram showing the configuration of a radio communication system; FIG. FIG. 2 is a diagram for explaining a communication state of group communication when a direct communication mobile station A communicates with a direct communication mobile station B in FIG. 1; In FIG. 1, when the direct communication mobile station A attempts to acquire the transmission right, the base communication mobile station 3 has already acquired the transmission right. FIG. 1 is a diagram for explaining a wireless communication system according to an embodiment; FIG. FIG. 4 is a diagram for explaining the configuration of a relay station according to an embodiment; 4 is a diagram for explaining communication modes of direct communication mobile stations within a communication area 50. FIG. 4 is a diagram illustrating another communication mode of a direct communication mobile station within communication area 50. FIG. FIG. 2 is a diagram for explaining the configuration of a direct communication mobile station according to an embodiment; It is a figure explaining the structure of the communication frame of the direct communication dedicated machine and direct communication mobile station based on an Example. 4 is a timing chart showing calling of a direct communication mobile station according to an embodiment; 4 is a timing chart showing call origination of a mobile station on the base station side according to the embodiment; 4 is a timing chart when a direct communication mobile station according to an embodiment has successfully acquired a transmission right; FIG. 10 is a timing chart when the direct communication mobile station fails to acquire the transmission right according to the embodiment; FIG. 4 is a timing chart when the mobile station on the base station side according to the embodiment has successfully acquired the transmission right;

Examples will be described below with reference to the drawings. However, in the following description, the same components may be denoted by the same reference numerals, and repeated descriptions may be omitted. In addition, in order to clarify the description, the drawings may be represented schematically as compared with actual embodiments, but they are only examples and do not limit the interpretation of the present invention.

(wireless communication system)
FIG. 4 is a diagram for explaining the radio communication system according to the embodiment. FIG. 5 is a diagram for explaining the configuration of a relay station.

The communication system 100 is a disaster prevention radio communication system, and includes a first base station BS1, a second base station BS2, a line control device 60 connecting the first base station BS1 and the second base station BS2, and a line control device. a communication console 70 connected to 60;

A radio communication system 100 has a base station BS1, a plurality of mobile stations 101 and 102 within a communication area 40 of the base station BS1, and a relay station (or relay device) 1. The relay station 1 has a base station via dedicated device (base station via radio) 10 for group communication with the base station BS1, and a direct communication mobile station (radio communication terminal) 201, 202 and a direct communication dedicated device (direct communication wireless device) 20 for performing group communication. In the relay station 1 , a dedicated device 10 for direct communication and a dedicated device 20 for direct communication are connected by a dedicated cable 11 . The communication area 50 is, for example, a mountainous area.

The wireless communication system 100 also has a base station BS2, a plurality of mobile stations 101b and 102b within the communication area 40b of the base station BS2, and a relay station (or relay device) 1b. The relay station 1b communicates directly with mobile stations (wireless communication terminals) 201b and 202b in a communication area 50b in an area outside the communication range of the base station BS2. and a direct communication dedicated machine 20b for communication. In the relay station 1b, the special-purpose machine 10b via the base station and the special-purpose machine 20b for direct communication are connected by a special cable 11b. The dedicated direct communication device 20 (20b) has a function of managing the group communication transmission rights of the direct communication mobile stations 201 and 202 (201b and 202b) under the direct communication dedicated device 20 (20b).

The base station BS1 communicates with the mobile stations 101 and 102 and the relay station 1 within the base station coverage area, which is the communicable area 40 of the base station BS1. The relay station 1 relays communication with the base station BS1 to the mobile stations 201 and 202 located within the dead area (communication area 50) outside the base station coverage area 40. FIG.

The base station BS2 communicates with the mobile stations 101b and 102b and the relay station 1b in the base station coverage area, which is the communicable area 40b of the base station BS2. The relay station 1b relays communication with the base station BS2 to the mobile stations 201b and 202b located within the dead area (communication area 50b) outside the base station coverage area 40. FIG.

Mobile stations 201 and 202 within the dead area (communication area 50) communicate with mobile stations 101 and 102 within the base station coverage area 40 using direct communication via relay station 1 and base station BS1. That is, mobile stations 201 and 202 within the dead zone (communication area 50) are connected to mobile stations 101 and 202 within base station coverage area 40 via direct communication dedicated device 20, base station via dedicated device 10, and base station BS1. 102 can be communicated with. Conversely, the mobile stations 101 and 102 within the base station coverage area 40 communicate with the mobile station 201 within the dead area (communication area 50) via the base station BS1, base station dedicated machine 10, and direct communication dedicated machine 20. , 202.

Mobile stations 201b and 202b in the dead area (communication area 50b) use direct communication to communicate with mobile stations 101b and 102b in the base station coverage area 40b via relay station 1b and base station BS2. That is, the mobile stations 201b and 202b within the dead area (communication area 50b) are connected to the mobile station 101b, 102b. Conversely, the mobile stations 101b and 102b within the base station coverage area 40b communicate with the mobile station 201b within the dead area (communication area 50b) via the base station BS2, the base station via dedicated machine 10b, and the direct communication dedicated machine 20b. , 202b.

Mobile stations 201 and 202 in the dead area (communication area 50) are dedicated to direct communication 20, dedicated via base station 10, base station BS1, line controller 60, base station BS2, dedicated via base station 10b. , and a dedicated direct communication device 20b, it is possible to communicate with mobile stations 201b and 202b in the dead area (communication area 50b). Conversely, the mobile stations 201b and 202b in the dead area (communication area 50b) are the direct communication dedicated machine 20b, the base station via dedicated machine 10b, the base station BS2, the line controller 60, the base station BS1, the base station via dedicated machine. 10 and a dedicated direct communication device 20, it is possible to communicate with mobile stations 201 and 202 in the dead area (communication area 50).

In the communication area 40 (40b), transmission from the base station BS1 (BS2) to the mobile stations 101, 102 (101b, 102b) and the base station via dedicated machine 10 (10b) uses, for example, the frequency f0 (f0b) communication. Transmission from the mobile stations 101, 102 (101b, 102b) and the dedicated machine 10 (10b) via the base station to the base station BS1 (BS2) is, for example, communication using the frequency f1 (f1b).

On the other hand, in the communication area 50 (50b), transmission and reception between the dedicated direct communication device 20 (20b) and the mobile stations 201, 202 (201b, 202b) are, for example, communications using the same frequency f2. be. Since the same frequency f2 is used for transmission and reception, transmission from the dedicated direct communication device 20 (20b) to the mobile stations 201 and 202 (201b and 202b) and from the mobile stations (201 and 202) to the dedicated communication device 20 is received in a different time zone.

(Relay station configuration)
Next, the configuration of relay station 1 will be described using FIG. Therefore, description of the configuration of the relay station 1b is omitted.

As shown in FIG. 5, the relay station 1 has a configuration in which two mobile stations (10, 20) are connected by a dedicated cable 11. Each mobile station (10, 20) and a dedicated machine 20 for direct communication. The dedicated cable 11 includes a dedicated cable 11a for transmitting control signals and a dedicated cable 11b for transmitting audio data. When the mobile station 101 makes a call in a group registered in the relay station 1, the dedicated machine 10 via the base station receives a group call from the mobile station 101, and at the same time, the controller 13 of the dedicated machine 10 via the base station The group number received by the special-purpose device 10 via the base station is transmitted to the control unit 23 of the direct-communication device 20 by serial communication through the dedicated cable 11a, and the direct-communication device 20 transmits the group number. A call originating from the dedicated direct communication device 20 is received at the mobile station 201 and the mobile station 102, and a call is established. The antenna AN10 of the dedicated machine 10 via the base station is connected to the transmitting section 11 and the receiving section 12. As shown in FIG. The antenna AN20 of the dedicated direct communication device 20 is connected to the transmitting section 21 and the receiving section 22 . It should be noted that the relay station 1 may be configured to allow transmission from either the dedicated machine 10 via the base station or the dedicated machine 20 for direct communication.

A transmission from the mobile station 101 is received by the receiving section 12 of the dedicated machine 10 via the base station via the base station BS1 and output to the control section 13 . When the control unit 13 determines that the transmission is from the mobile station 101 , the control unit 13 outputs voice to the relay unit 14 . The relay unit 14 of the dedicated device 10 via the base station transmits the data to the relay unit 24 of the direct communication dedicated device 10 by serial transmission of the dedicated cable 11b. station 202.

A transmission from the mobile station 201 is received by the receiving section 22 of the dedicated direct communication device 20 and output to the control section 23 . When the control unit 23 determines that the voice is transmitted from the mobile station 201 , the control unit 23 outputs voice to the relay unit 24 . The relay section 24 of the direct communication dedicated machine 20 transmits the data to the relay section 14 of the dedicated machine 10 via the base station by serial transmission of the dedicated cable 11b, and from the relay section 14 through the control section 23, via the base station BS1 to the base station. It is transmitted to mobile stations 101 and 102 in the communication coverage area 40 of BS1.

The direct communication dedicated machine 20 has a response function to a direct communication (relay) simplex call setting request, a direct communication simplex call setting (relay) transmission function, and an ID number, which will be described later, according to a control program executed by the control unit 23. It has a transmission function of an added synchronization burst SB (B/I=I, ID=“direct communication mobile station 201”).

(communication mode)
FIG. 6 is a diagram for explaining communication modes of direct communication mobile stations within the communication area 50. As shown in FIG. FIG. 7 is a diagram illustrating another communication mode of a direct communication mobile station within communication area 50. In FIG.

As shown in FIG. 6, a direct communication mobile station 201 and a direct communication mobile station 202 within a communication area 50 are, for example, like transceivers. Direct communication is possible without intervening the dedicated machine 20 . This communication mode can be referred to, for example, as a first communication mode or a direct communication mode.

FIG. 7 shows a newly added communication mode according to the present invention. In this communication mode, the direct communication mobile station 201 and the direct communication mobile station 202 within the communication area 50 communicate via the direct communication dedicated machine 20 . In this communication mode, it is also possible to relay transmissions from dedicated machine 10 via base station to direct communication mobile station 201 and direct communication mobile station 202 via direct communication dedicated machine 20 . This communication mode can be referred to, for example, as a second communication mode or a direct communication (relay) group communication mode. In the second communication mode, the dedicated direct communication device 20 also manages the right of transmission of the direct communication mobile stations (201, 202) and the right of transmission from the dedicated device 10 via the base station. That is, in the second communication mode, relay station 1 can be regarded as managing transmission rights to direct communication mobile station 201 and direct communication mobile station 202 within communication area 50 .

(Configuration of direct communication mobile station)
FIG. 8 is a diagram for explaining the configuration of a direct communication mobile station. The configuration of the direct communication mobile station 201 shown in FIG. 8 is applicable to other direct communication mobile stations (202, 201b, 202b) shown in FIG. FIG. 8 illustrates the configuration of a direct communication mobile station 201 as a representative of direct communication mobile stations.

A direct communication mobile station 201, which is a wireless communication terminal, is connected to an antenna AT1, a transmitter T and a receiver R to which the antenna AT1 is connected, and a transmitter T and a receiver R. and a press-to-talk switch PTT connected to the central processing unit CPU. The direct communication mobile station 201 also has a speaker SP, a microphone MIC, and a speech coding and decoding device CODEC provided between the speaker SP and microphone MIC and the central processing unit CPU.

When the press-to-talk switch PTT is pressed, the direct communication mobile station 201 enters the transmission mode, and the voice spoken into the microphone MIC is encoded by the voice encoding/decoding device CODEC, and sent to the central processing unit CPU and transmitted. It is transmitted as a transmission signal from the antenna AT1 via the part T. On the other hand, when the press-to-talk switch PTT is not pressed, the received signal received from the antenna AT1 passes through the receiver R and the central processing unit CPU, is decoded by the voice coding and decoding device CODEC, and is sent to the speaker SP. is output as an audio signal from

The direct communication mobile stations (201, 202, 201b, 202b) shown in FIG. Frequency switching function when simplex call setup (relay) is received Synchronous burst SB (B/I=I, ID=“direct communication mobile station 201”) with ID number, which is the terminal identification number of its own station and a voice generation function to notify the user of the success or failure of acquisition of the right to transmit.

(Structure of communication frame)
FIG. 9 is a diagram for explaining the structure of a communication frame between a direct communication dedicated machine and a direct communication mobile station in the second communication mode.

In the second communication mode (direct communication (relay) group communication mode), as shown in FIG. 9A, one frame is, for example, 40 ms, and each frame is 10 ms long. Contains four communication slots. Of the four communication slots, the 0th slot is indicated by CH1 and the 2nd slot is indicated by CH2. The time from the beginning of slot 0 CH1 to the beginning of slot 2 CH2 is, for example, 20 ms. The first slot and the third slot can be empty slots. 9B shows the transmission/reception status of the direct communication dedicated machine 20, and FIG. 9C shows the transmission/reception status of the direct communication mobile station, for example, the direct communication mobile station 201. FIG. In 0 slot CH1, the direct communication dedicated machine 20 transmits Tx, and the direct communication mobile station 201 receives Rx. In the second slot CH2, the direct communication mobile station 201 transmits Tx, and the dedicated direct communication device 20 receives Rx (the second slot CH2 is the receiving slot of the dedicated direct communication device 20). In (B) and (C) of FIG. 9, communication slots other than transmission Tx and reception Rx are idle (I) slots.

That is, slot 0 CH1 is a transmission slot for direct communication dedicated device 20 and a reception slot for direct communication mobile station 201 . 2-slot CH2 is a transmission slot for direct communication mobile station 201 and a reception slot for direct communication dedicated machine 20 .

In (B) and (C) of FIG. 9, an idle (I) slot is inserted between a transmission slot (transmission Tx) and a reception slot (reception Rx) as an offset between transmission and reception. However, in particular, the idle (I) slot does not have to be inserted, and at least an empty state for preventing interference should be provided between the transmission slot (transmission Tx) and the reception slot (reception Rx). .

(Timing chart)
Next, the second communication mode (direct communication (relay) group communication mode) will be described in detail with reference to FIGS. 10 to 14. FIG. 10 to 14, the direct communication mobile stations (201, 202), the direct communication dedicated device 20, the base station BS1, and the mobile station 101 on the base station side are taken as examples in the second communication mode (direct communication ( A timing chart of (relay) group communication mode) will be explained. 10 to 14, CAC means common access channel and USC means user dedicated channel.

(Call origination of direct communication mobile station)
FIG. 10 is a timing chart showing a direct communication mobile station originating a call. In the direct communication (relay) group communication mode, the direct communication mobile station requests the second communication mode (direct communication (relay) group communication mode). 4 shows a timing chart for the case.

In step S1, the direct communication mobile station 201 sends a direct communication (relay) simplex call setup request to the direct communication dedicated machine 20 via the CAC to request the direct communication (relay) group communication mode. . A direct communication (relay) simplex call setup request is transmitted, for example, by pressing the press-to-talk switch PTT of the direct communication mobile station 201 . A group number for group communication is added to the direct communication (relay) simplex call setup request. The group number is, for example, No. 10 is the first group (201, 202, 20, 101), No. 20 can be the second group (201, 101, 101b, 201b), and so on. For example, when a group number (No. 10) is added to the direct communication (relay) simplex call setup request, group communication between the communication terminals (201, 202, 20, 101) registered in the first group is allowed.

In step S 2 , direct communication dedicated device 20 that has received the direct communication (relay) simplex call setup request executes a group communication start sequence with base station BS 1 and base station side mobile station 101 .

In step S<b>3 , the dedicated direct communication device 20 searches for available channels under the direct communication dedicated device 20 .

In step S4, when an available empty channel is searched in step S3, in order to perform group communication using the empty channel as a communication channel, the direct communication dedicated machine 20 performs direct communication simplex call setting (relay) as follows: CAC is used to transmit to direct communication mobile stations (201, 202).

In step S5, in preparation for group communication, the direct communication dedicated machine 20 and the direct communication mobile stations (201, 202) are switched to a frequency corresponding to the communication channel.

In step S6, the direct communication dedicated device 20 continues to transmit synchronization bursts SB (B/I=I) indicating idle to the direct communication mobile stations (201, 202) using USC when transmission is possible.

That is, when direct communication mobile station 201 originates "direct communication (relay) group communication", direct communication dedicated machine 20 completes group communication call connection with base station BS1, and then "direct communication simplex call setup (relay)” to the direct communication mobile stations 201 and 202 under the relay umbrella of the direct communication dedicated device 20. After that, the direct communication dedicated machine 20 transmits a synchronization burst SB (B/I=I) indicating idle in slot 0 (CH1) of the communication channel. The direct communication mobile stations 201 and 202 complete the call connection by receiving SB (B/I=I) on the communication channel.

This completes the setting of group communication in the direct communication (relay) group communication mode.

(Call from mobile station on base station side)
FIG. 11 is a timing chart showing call origination of a mobile station on the base station side. ) is requested.

In step S10, when the mobile station 101 on the base station side requests the direct communication (relay) group communication mode, the direct communication dedicated machine 20 executes a group communication start sequence from the base station side.

In step S<b>11 , the dedicated direct communication device 20 searches for available channels under the direct communication dedicated device 20 .

In step S12, when an available empty channel is searched in step S3, in order to perform group communication using the empty channel as a communication channel, the direct communication dedicated machine 20 sets up (relays) a direct communication simplex call, CAC is used to transmit to direct communication mobile stations (201, 202).

In step S13, as preparation for group communication, the direct communication dedicated machine 20 and the direct communication mobile stations (201, 202) are switched to a frequency corresponding to the communication channel.

In step S14, the direct communication dedicated device 20 continues to transmit synchronization bursts SB (B/I=I) indicating idle to the direct communication mobile stations (201, 202) using USC when transmission is possible.

When "direct communication (relay) group communication" is transmitted from the base station BS1 side, the direct communication dedicated machine 20 performs "direct communication simplex call setup (relay) ” to the direct communication mobile stations 201 and 202 under the relay umbrella of the direct communication dedicated device 20 . After that, the direct communication dedicated machine 20 transmits a synchronization burst SB (B/I=I) indicating idle in slot 0 (CH1) of the communication channel. The direct communication mobile stations 201 and 202 complete the call connection by receiving SB (B/I=I) on the communication channel.

This completes the setting of group communication in the direct communication (relay) group communication mode.

(Successful Acquisition of Right of Transmission by Direct Communication Mobile Station)
FIG. 12 shows a timing chart when the direct communication mobile station has successfully acquired the right to transmit. FIG. 12 shows that when the group communication setting is completed according to FIG. 10 or 11 and the group communication is being performed, the direct communication mobile station 201 requests the transmission right and the direct communication mobile station 201 acquires the transmission right. indicates the case.

Step S20 shows a situation in which group communication is being performed.

In step S21, the direct communication dedicated device 20 transmits a synchronization burst SB (B/I=I, ID="none") to which no ID number is added to the direct communication mobile stations 201 and 202 using USC. and send that it is idle.

In step S22, since the direct communication mobile station 201 acquires the transmission right, the direct communication mobile station 201 receives a synchronization burst SB (B/I=I, ID=“direct The communication mobile station 201 ″) is sent directly to the dedicated communication device 20 using USC. Here, direct communication mobile station 201 indicates its own ID number as 201 .

In step S23, the direct communication dedicated device 20 adds the received ID of the direct communication mobile station 201, and transfers the added synchronization burst SB (B/I=I, ID=“direct communication mobile station 201”) to USC. is used to directly send to the communication mobile station 201 . Note that the direct communication dedicated machine 20 continues to repeatedly execute steps S22 and S23 until the result of acquisition of the transmission right is received.

In step S24, the dedicated direct communication device 20 performs a transmission right acquisition sequence with the base station BS1. Here, it is assumed that the direct communication mobile station 201 has successfully acquired the transmission right.

In step S25, the direct communication dedicated device 20 uses USC to transmit the result of acquisition of the transmission right to the direct communication mobile station 201 through the directly associated control channel DACCH (transmission right acquisition result OK). As a result, direct communication mobile station 201 succeeds in acquiring the right to transmit. The direct communication mobile station 201 notifies the user of the direct communication mobile station 201 of successful acquisition of the transmission right by generating a sound (for example, a beep) from the speaker SP.

In step S26, the direct communication mobile station 201 uses USC to transmit voice data to the dedicated direct communication device 20 as TCH (voice). Voice data is generated by pressing the press-to-talk switch PTT of the direct communication mobile station 201 and speaking into the microphone MIC.

In step S27, the direct communication dedicated device 20 transmits the TCH (voice) received in step S26 to the direct communication mobile station 202 using USC.

As a result, the voice data of the direct communication mobile station 201 is supplied to the communication terminals (for example, 201, 202, 20, 101) registered in the group number, and the communication terminals (for example, 201, 202, 20, 101) Sound is generated from each speaker (SP).

(Failure to acquire transmission right of direct communication mobile station)
FIG. 13 shows a timing chart when the direct communication mobile station fails to acquire the right to transmit. FIG. 13 shows that when the group communication setting is completed according to FIG. 10 or 11 and group communication is being performed, the direct communication mobile station 201 requests the transmission right, and the direct communication mobile station 201 acquires the transmission right. failed.

Step S30 shows a situation in which group communication is being performed.

In step S31, the direct communication dedicated device 20 transmits a synchronization burst SB (B/I=I, ID="none") to which no ID number is added to the direct communication mobile stations 201 and 202 using USC. and send that it is idle.

In step S32, since the direct communication mobile station 201 acquires the transmission right, the direct communication mobile station 201 receives a synchronization burst SB (B/I=I, ID=“direct The communication mobile station 201 ″) is sent directly to the dedicated communication device 20 using USC. Here, direct communication mobile station 201 indicates its own ID number as 201 .

In step S33, the direct communication dedicated device 20 uses the USC to transmit the received synchronization burst SB (B/I=I, ID=“direct communication mobile station 201”) to which the ID of the direct communication mobile station 201 is added. It is sent to the direct communication mobile station 201 . Note that the direct communication dedicated machine 20 continues to repeatedly execute steps S32 and S33 until the result of acquisition of the transmission right is received.

In step S34, the direct communication dedicated device 20 performs a transmission right acquisition sequence with the base station BS1. Here, it is assumed that the direct communication mobile station 201 has failed to acquire the transmission right.

In step S35, the direct communication dedicated device 20 uses USC to transmit a failure to acquire the transmission right to the direct communication mobile station 201 through the directly associated control channel DACCH (failure to acquire the transmission right). As a result, direct communication mobile station 201 recognizes that acquisition of the transmission right has failed, and stops transmission in step S32. The direct communication mobile station 201 notifies the user of the direct communication mobile station 201 of failure to acquire the transmission right by generating a sound (eg, boo) from the speaker SP.

(Successful acquisition of the transmission right of the mobile station on the base station side)
FIG. 14 shows a timing chart when the mobile station on the base station side has successfully acquired the transmission right. FIG. 14 shows that when the group communication setting is completed according to FIG. 10 or 11 and group communication is being performed, the mobile station 101 on the base station side requests the transmission right, and the mobile station 101 acquires the transmission right. is successful.

Step S40 shows a situation in which group communication is being performed.

In step S41, the base station BS1 transmits the idle traffic channel TCH (B/I=I) to the mobile station 101 and the direct communication equipment 20. FIG.

In step S42, the direct communication device 20 directly communicates the synchronization burst SB (B/I=I, ID="none") using USC based on the reception of TCH (B/I=I). It transmits to the mobile stations 201 and 202 and transmits that they are in an idle state.

In step S43, the mobile station 101 sends a speech request SB2 to the base station BS1 based on the reception of TCH (B/I=I) in order to acquire the transmission right. Speech request SB2 is sent by pressing the press-to-talk switch of mobile station 101, for example.

In step S44, base station BS1 sends speech approval SB3 to mobile station 101 in response to speech request SB2.

In step S45, the mobile station 101 sends an utterance acknowledgment SB4 to the base station BS1 in response to the reception of the utterance acknowledgment SB3.

In step S46, the base station A sends a traffic channel TCH (B/I=B) indicating busy to the mobile station 101 and the direct communication dedicated machine 20 in response to the reception of the speech acknowledgment SB4. As a result, mobile station 101 succeeds in acquiring the right to transmit.

In step S47, the direct communication dedicated device 20 responds to the reception of TCH (B/I=B) and transmits to the direct communication mobile stations 201 and 202 that it is in an idle state.

After that, the mobile station 101 sends TCH (voice) to the base station BS1, and the base station BS1 sends the received TCH (voice) to the dedicated communication device 20 directly. The direct communication dedicated machine 20 transmits the received TCH (voice) to the direct communication mobile stations 201 and 202 under its umbrella.

Thereby, the voice data of the mobile station 101 is supplied to the communication terminals (for example, 201, 202, 20, 101) registered with the group number.

As described above, the direct communication dedicated machine 20 manages the transmission right of the direct communication mobile stations (201, 202) under direct communication, and sends the acquisition result (whether or not) of the transmission right to the direct communication mobile station (201, 202). to notify. After the direct communication mobile stations 201 and 202 receive the transmission right acquisition result from the direct communication dedicated machine 20, they transmit voice to the communication terminals (for example, 201, 202, 20 and 101) registered in the group number.

This solves the problem that the voice at the beginning of the call is cut off by transmitting the voice data after the acquisition of the transmission right is announced in the wireless transmission system 100 . In addition, since the acquisition of the transmission right is managed by the direct communication dedicated machine 20, conflicts in acquisition of the transmission right are eliminated, and voices cannot be heard.

Although the invention made by the present inventor has been specifically described above based on the examples, it goes without saying that the invention is not limited to the above-described embodiments and examples, and can be variously modified. .

1: Relay station (relay device)
10: Dedicated device via base station (unrelated device via base station)
20: Direct communication dedicated machine (direct communication unrelated machine)
60: Line control device 70: Communication console 100: Radio communication systems 101, 102: Mobile stations on the base station side 201, 202: Direct communication mobile stations (radio communication terminals)
AT10, AT20, AT1: antenna BS1, BS2: base station

Claims (8)

a base station;
a plurality of mobile stations;
a relay station;
A first communication mode in which the plurality of mobile stations directly communicate with other mobile stations without intervening the relay station, and a second communication mode in which direct communication group communication is performed with the other mobile stations via the relay station. mode and works with
The relay station
a base station-routed wireless device for performing group communication with the base station;
a direct communication radio for performing direct communication group communication with the mobile station in an area where the base station is out of communication range;
The radio communication system according to claim 1, wherein the direct communication radio manages transmission rights of the mobile station and the base station-routed radio when receiving a request for the direct communication group communication in the second communication mode from the mobile station. In claim 1,
A radio communication system according to claim 1, wherein, when requesting the transmission right to the direct communication radio, the mobile station sends a synchronization burst signal to which the ID number of the mobile station is added to the direct communication radio. In claim 1,
The wireless communication system, wherein when requesting the group communication, the mobile station transmits a setting request to which a group number is added to the direct communication wireless device. In claim 1,
a communication frame between the direct communication radio and the mobile station includes a plurality of slots;
transmission from the direct communication radio to the mobile station uses one slot of the plurality of slots;
A wireless communication system, wherein transmissions from the mobile station to the direct communication radio use another slot different from the one slot. a wireless device via a base station for performing group communication with the base station;
a direct communication radio for performing direct communication group communication with a mobile station in an area where the base station is out of communication range,
A first communication mode in which the mobile station directly communicates with another mobile station without intervening the relay device, and a second communication mode in which the direct communication group communication is performed with the other mobile station via the relay device. and works with
The relay device, wherein the direct communication radio manages transmission rights of the mobile station and the base station-routed radio when receiving a request for the direct communication group communication in the second communication mode from the mobile station. In claim 5,
The relay device, wherein the direct communication radio sends a synchronization burst signal to which the ID number of the mobile station is added to the mobile station when the mobile station requests the transmission right. In claim 5,
The relay device, wherein the direct communication radio transmits a setting instructing frequency switching to the mobile station when the mobile station requests the group communication. In claim 5,
a communication frame between the direct communication radio and the mobile station includes a plurality of slots;
transmission from the direct communication radio to the mobile station uses one slot of the plurality of slots;
A relay apparatus, wherein transmission from the mobile station to the direct communication radio uses another slot different from the one slot.

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