JP2590753B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system, and more particularly to a normal one-to-one communication between radio terminal stations via a base station.
The present invention relates to a wireless communication system that performs communication and also performs conference-type communication between a plurality of wireless terminal stations using the same wireless channel.

[0002]

2. Description of the Related Art Wireless communication has a number of advantages over wired communication, such as the ability to perform mobile communication, low installation costs for facilities, and the possibility of short-term construction. I have.

FIG. 8 is a block diagram showing an example of a general local wireless network to which the present invention can be applied. An area wireless base station (ABS) 1 installed at the center of the area is an indoor communication device (IDU: I).
nDoor Unit) 2, outdoor communication device (ODU: O)
out Door Unit) 3 and base station antenna 4
It is composed of The outdoor communication device 3 is a duplexer (DP
X) 3a, low noise amplifier (LNA: Low Noise)
Amplifier 3b and high power amplifier (HP
A: High Power Amplifier) 3c
Etc.

The local radio base station 1 is a radio terminal (RT)
S: Radio Terminal Station (S: Radio Terminal Station) and can also communicate with a subscriber of a public telephone network (PSTN). The wireless terminal station
It comprises a plurality of fixed stations 5a and a plurality of mobile stations 5b. Generally, in a wireless communication system, the local wireless base station 1 uses a common control line (CSC: Common Signal).
Each time a call is generated between the fixed station 5a and the mobile station 5b by using ng Control, a wireless channel is allocated to perform communication service. The line control is uniformly performed by the indoor communication device 2.

FIG. 9 shows an example of frequency allocation of the above-mentioned radio channel. In the figure, RTS transmission (BS reception) indicates the frequency of the radio channel when transmitting from the fixed station 5a and the mobile station 5b to the radio base station 1, and RTS reception (BS transmission) is from the radio base station 1 to the fixed station. 5 shows the frequency of the wireless channel when transmitting to the mobile station 5b. Normally, when the channel numbers of these transmission radio channels and reception radio channels are the same, they are arranged at a constant frequency f _SEP .

[0006] During communication, the wireless base station 1 connects the receiving unit and the transmitting unit in the indoor communication device 2 to each other to communicate with the fixed station 5a or the mobile station 5b by the wireless relay method.
Alternatively, a call is made between the fixed station 5a or the mobile station 5b and the outside of the area. Figure 1 shows various types of calls in this case.
0 is shown. FIG. 10A shows two radio communication channel demodulators RCU1-D and RCU2-D in indoor communication device 2.
Are separately assigned to the two radio channel modulators RCU1-M and RCU2-M in the same indoor communication device 2, and indicate a call format in a case where a call is performed in a full duplex mode (Full Duplex). The transmission signal from the fixed station 5a or the mobile station 5b is transmitted one way to the partner station, and is not received by the radio base station 1.

FIG. 10B shows that one radio communication channel demodulation device RCU3-D in the indoor communication device 2 has one radio channel modulation device RCC in the same indoor communication device 2.
This shows a call format when a call is assigned to U3-M, and all fixed stations 5a and mobile stations 5b are assigned a common radio channel to perform a call.
It corresponds to a call of the multi channel access method.

Further, FIG. 10C shows that two radio communication channel demodulators RCU4-D and RCU5-D in the indoor communication device 2 of the radio base station in the area are connected to another area, for example, a public switched telephone. Two radio channel modulators ICU1-M and ICU2 in the same indoor communication device for communicating with the network
-M and the demodulation devices ICU1-D and ICU2-D are separately allocated to the modulation devices RCU4-M and RCU5-M, respectively, and show the communication format in the case of the communication in the duplex mode.

As is apparent from FIG.
S (fixed station 5a and / or mobile station 5b)
If you can talk in the system, the frequency will be used effectively. Moreover,
By assigning a common channel to a plurality of RTSs, a wireless conference can be performed using one wireless channel. Taking advantage of this feature, the MCA system has been widely used conventionally.
In Japan, the specifications are based on the official document “RCR STD
-24 "800 MHz band (narrow band) MCA Radio equipment standard standards for radio stations performing land mobile communication" and the like.

[0010] Originally, this MCA system is mainly used for mobile communication for business use, and is mainly used for communication in the form of a radio conference. However, methods for performing various communications belonging to a plurality of groups have been proposed. (JP-A-62-81823, title of invention "MCA land mobile communication multiple group incoming call system").

FIG. 11 is a block diagram showing an example of a mobile station used in the conventional radio communication system proposed in this proposal. The mobile station includes an antenna 101, a transmission / reception changeover switch 10
2, receiving section 103, data demodulator 104, control circuit 10
5, data modulator 106, signal adder 107, transmission unit 1
08, frequency synthesizer section 109 and handset 110
It is composed of The control circuit 105 is constituted by a microcomputer, and includes an interface 111, a central processing unit (CPU) 112, an EPRO
M113 and IDROM 114 are provided.

This mobile station is a mobile station of the MCA system. When a mobile station receives a call, it receives control data from a control station (radio base station) and transmits user code information in the control data to a group in the ID ROM 114. User code information read from the address selected by the selection switch and the CPU
In step 112, comparison and collation are performed to determine whether or not both match. If they match, a call is made on the specified call channel.

If they do not match, the IDROM
The user code of the next group is read from 114, and it is determined whether or not this code matches the user code information in the received control data. If they match, the call is switched to the call channel specified by the group. In this way, the mobile station can be called at any time, no matter which group it belongs to.

[0014]

However, this mobile station is a mobile station of a press-to-talk system which always requires the user to manually operate the transmission / reception switch 102 for transmission and reception. Can not do it. The reason is that, in the case of the duplex system, when a large number of wireless terminal stations communicate using the same wireless channel, oscillation may occur in a closed loop in which the handset is turned back.

Therefore, in such a conventional system, a large number of mobile stations such as mobile stations belonging to the same group use the same wireless channel, so that only one station transmits data and the other station listens to a call. In other words, collision at the time of speaker change becomes a problem. This collision becomes more frequent as the number of wireless terminal stations belonging to the same group increases.

Conventionally, this conventional system can avoid a collision problem by a mode of headquarters or the like, so that there is no problem in the case of business communication such as a transportation business such as a truck and a distribution business. However, a communication network connected to an unspecified number of wireless terminal stations or a public network, such as a regional radio, has a problem that it cannot be applied because the above-mentioned collision problem cannot be avoided.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a wireless communication system in which an unspecified number of wireless terminal stations and subscribers of a public network can share the same communication channel in a complete duplex wireless communication network to execute intra-group communication.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a wireless base station which is capable of wireless communication with a wireless base station. Access using a common control line, the wireless base station in the wireless communication system to allocate a free communication channel to the wireless terminal station that made a call request using the common control line, each of the plurality of wireless terminal stations, Stores a unique number of the own station and a group number indicating a group to which the own station belongs. Means for accessing using a group number, and a speaking right request signal transmitting means for transmitting a speaking right request signal requesting a speaking right to the wireless base station after accessing using the group number,
Transmitting means for transmitting a voice signal addressed to all other wireless terminal stations to which the own station belongs after acquiring the floor.
When the wireless base station is accessed using the unique number, the wireless base station notifies the communication channel assigned to each of the wireless terminal stations calling and the wireless terminal station having the unique number, and uses the group number. When accessed, a communication channel notification means for notifying the same communication channel allocated to all wireless terminal stations having the same group number as the group number, and a communication between groups when a call is started using the group number. A management means for transmitting a talk permission signal to only one wireless terminal station having a floor and managing the floor is provided among the plurality of wireless terminal stations in the same group.

In the present invention, the floor request signal transmitting means includes a floor request switch, a reception signal presence / absence detector for detecting the presence / absence of a reception signal, and a reception signal presence / absence detector detecting that there is no reception signal. A generation circuit for generating a floor request signal when the floor request switch is turned on when the switch is on, and means for wirelessly transmitting the floor request signal from the generation circuit to the radio base station. A display for displaying a possible state, a utterance permission signal detector for detecting a utterance permission signal addressed to the own station, and a utterance possible state displayed on the display when the utterance permission signal is detected by the utterance permission signal detector. And control means for making the transmitting section operable, and means for wirelessly transmitting the audio signal of the own station via the transmitting section.

Further, the managing means in the present invention comprises: decoding means for receiving the floor request signal from the floor request signal transmitting means and decoding the request source; And a speech permission signal transmission circuit for transmitting a speech permission signal to the requesting wireless terminal station using the number, and further, after transmitting the speech permission signal, receives and decodes the floor right request signal for a predetermined period of time. The configuration has a priority processing circuit that stops.

The floor request signal transmitting means according to the present invention includes a detection circuit for detecting the presence or absence of a transmission signal of the own station, a floor right being given to the own station, and a floor request switch turned on. And a control circuit for causing the generation circuit to generate the floor request signal each time the disconnection of the transmission signal is detected by the detection circuit.

The radio base station according to the present invention comprises a plurality of radio channel demodulators, a common control channel demodulator, a plurality of radio channel modulators, a common control channel modulator,
An inter-region communication network receiving unit and an inter-region communication network transmitting unit, a connection between an arbitrary wireless channel demodulator and an arbitrary wireless channel modulator, an inter-region communication network receiving unit and an inter-region communication network transmitting unit And a baseband switch for connecting to any one of the above-mentioned radio channel demodulation devices and radio channel modulation devices, and a call connection control device for controlling connection of the baseband switch and having a management means.

[0023]

According to the present invention, when an arbitrary wireless terminal station accesses a wireless base station using a group number, all wireless terminal stations having the same group number as the group number have the same assigned group number. The intra-group call is performed by the call channel, and in the intra-group call, a speech permission signal is transmitted to only one of the plurality of wireless terminal stations participating in the intra-group call by the management unit of the wireless base station. Since the transmission and the right to give the floor are managed, even if the same communication channel is used, it is possible to avoid collision of transmission signals at the time of speaker change.

Also, each of the plurality of wireless terminal stations can perform one-to-one communication when accessed using the unique number of the partner wireless terminal station with which communication is to be performed, and can communicate with the wireless base station using the group number. When access is made using the common control line, intra-group communication can be performed, and during the intra-group communication, a floor right request signal for acquiring a floor can be transmitted at any time by the floor right request signal transmitting means.

Further, in the present invention, since the voice signal of the own station transmitted after acquiring the right to speak by the transmitting means of the wireless terminal station is received by all the wireless terminal stations in the same group, the return of the local station by the wireless base station is performed. Can receive and listen to the transmitted audio signal.

In the present invention, since the management means of the radio base station has a priority processing circuit for stopping reception and decoding of the floor right request signal for a predetermined period of time after transmitting the floor permission signal, When the speech request signals are transmitted from the terminal stations almost simultaneously, the first-come-first-served process of transmitting the speech permission signal only to the earliest wireless terminal station can be performed.

Further, the speaking terminal request signal transmitting means of the wireless terminal station according to the present invention is configured to interrupt the transmitting signal of the own station while the speaking station is given the speaking right and the speaking right request switch is turned on. Since the floor right request signal is generated each time is detected, the floor can be secured even if the transmission voice signal of the own station is interrupted.

Further, in the present invention, the base station switches the radio base station between the inter-region communication network receiving unit and the inter-region communication network transmitting unit and any of the radio channel demodulators and radio channel modulators. Therefore, communication can be performed between a wireless terminal station in the area and a terminal station outside the area.

[0029]

Next, an embodiment of the present invention will be described. This embodiment is applied to the local wireless network shown in FIG.
The local radio base station 1 is configured as shown in FIGS.
It is characterized in that the wireless terminal station including the fixed station 5a and the mobile station 5b is configured as shown in FIGS.

First, the configuration of the radio base station 1 will be described with reference to FIGS. FIG. 1 shows a configuration diagram of an embodiment of a wireless base station of the system of the present invention. 8, the same components as those in FIG. 8 are denoted by the same reference numerals. In FIG. 1, an indoor communication device 2 includes a receiving device 21, a common control line demodulation device (CSCD) 22, and a plurality of radio channel demodulation devices (RCC).
UD) 23-1 to 23-n, baseband switch (B
SW) 24, common control line modulator (CSCM) 25,
A plurality of radio channel modulators (RCUMs) 26-1 and 26-2
6-n, transmitting device 27, call connection control device (CCC) 2
8. Demodulator for communication with outside (ICUD: In)
ter Channel Unit Demodula
ter) 29 and a modulator (I) for communicating with the outside.
CUM) 30.

The BSW 24 sets a communication path between the radio channel demodulators 23-1 to 23-n and the radio channel modulators 26-1 to 26-n under the control of the call connection controller 28. Means these with ICUD29 and ICUM3
A communication path between 0 is set.

The outdoor communication device 3 has a duplexer (DP)
X) 3-1, a low noise amplifier (LNA) 3-2, a high power amplifier (HPA) 3-3, and the like. The demultiplexer 3-1 is connected to the antenna 4, supplies a signal received by the antenna 4 to the LNA 3-2, outputs a high-frequency signal extracted from the HPA 3-3 to the antenna 4, and wirelessly transmits the high-frequency signal.

When the wireless base station 1 having such a configuration is accessed using a unique number, the wireless base station 1 notifies a communication channel assigned to each of the other wireless terminal station having the unique number and the wireless terminal station that has made a call. When the access is performed using the group number, the BSW 24 is controlled under the control of the call connection control device 28 by using the same communication channel allocated to all wireless terminal stations having the same group number as the group number. , And notify the wireless terminal station using the common control line.

Although the block configuration of the radio base station shown in FIG. 1 is the same as that of the radio base station in the conventional MCA system, in this embodiment, the configuration of the call connection control device 28 is different from the conventional one. In contrast, at the time of an intra-group call initiated by using a group number described later, a speech permission signal is transmitted to only one of the plurality of radio terminal stations in the same group having the right to speak to manage the right to speak. It is characterized in that it has a configuration having a managing means for performing such operations.

FIG. 2 is a block diagram showing one embodiment of the call connection control device 28. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals. In FIG. 2, the call connection control device 28
Has a management means including a two-input AND circuit 281, a TRQ decoding-TA generation circuit 282, and a timer 283.

In other words, this management means requests a floor right (TRQ: Talk R) during intra-group communication (wireless conference).
request), receives the request, decodes the requesting source, and uses the unique number of the decoded requesting wireless terminal to permit the requesting wireless terminal to speak (TA: Talk Assig).
(Nent) signal, a TRQ decoding-TA generation circuit 282, and a timer 283 and an AND circuit 281 which constitute a priority processing circuit for stopping reception and decoding of the floor right request signal for a predetermined period of time after transmitting the floor permission signal. Consists of

The operation of the circuit shown in FIG. 2 will be described. Normally, the timer 283 outputs a high-level signal, so that the gate of the AND circuit 281 is "open". On the other hand, as will be described later, during intra-group communication (wireless conference), wireless terminal stations in the same group make a call using the same call channel assigned by the wireless base station 1.

Accordingly, even in the radio base station 1, the n radio channel demodulators (RCUD) 23-1 to 23-i and the radio channel modulator (RCUM) 26-1 are controlled by the baseband switch (BSW) 24. 26-n corresponding to the assigned communication channel, for example, i
A second wireless channel demodulator 23-i and a wireless channel modulator 26-i are connected via a selector 32 as shown in FIG. 2 (a communication path is set).

The output demodulated signal of the radio channel demodulator 23-i is supplied to the selector 32 via the BSW 24, while being supplied to the control signal generator 31 to generate a control signal. This control signal is transmitted through an AND circuit 281 to T
The signal is supplied to the RQ decryption-TA generation circuit 282 as a floor request signal.

Then, TRQ decoding-TA generation circuit 282
Decodes the contents based on the input control signal, generates a speech permission signal (TA) to the transmission source, and
2 and at the same time, a select signal is supplied to the selector 32 to transmit the speech permission signal to the radio channel modulator 26-i.
The switching of the selector 32 is controlled so as to output to the selector 32.
Further, the TRQ decoding-TA generation circuit 282 also supplies the select signal to the timer 283, and activates the timer 283 when the selector 32 completes the operation of selecting the speech permission signal.

The timer 283 keeps outputting a low-level signal for a predetermined period of time by the above-mentioned activation.
The D circuit 281 is set to the gate “closed” state. Therefore, once the speech permission signal is output, the call connection control circuit 28 stops accepting the floor request for a certain period of time determined by the timer 283, and performs first-come-first-served processing.

Next, the configuration of the wireless terminal station 5 which is the fixed station 5a or the mobile station 5b will be described. FIG. 3 shows a configuration diagram of an embodiment of the wireless terminal station in the system of the present invention. In the figure, a wireless terminal station 5 includes a terminal communication device 34, an antenna 3
5, a handset 36, a speaking right request switch 37, a speaking permission display 38, and the like.

The terminal communication unit 34 includes a communication control circuit 40, a duplexer 41, an LNA 41, a frequency down converter (D / C: D
own Converter 43, demodulator 44, reception baseband processor (RXBBP) 45, splitter 46, transmission baseband processor (TXBBP) 4
7, switch 48, modulator 49, local signal generation circuit 5
0, frequency rise converter (U / C: Up Convert)
er) 51 and HPA 52.

The output terminal of the demodulator 44 is connected to the RXBBP 45 and the handset 36. In addition, the communication control circuit 4
0 is a signal input from the floor request switch 37, the RXBBP 45 and the branching unit 46,
A circuit that outputs a control signal to the TXBBP 47, the switch 48, the modulator 49, and the local signal generation circuit 50,
This is a circuit that controls each part of the terminal communication device 34.

FIG. 4 is a circuit diagram of one embodiment of the communication control circuit 40. 3, the same components as those of FIG. 3 are denoted by the same reference numerals. In FIG. 4, a portion other than the speaking right request switch 37 and the speaking permission display 38 is a communication control circuit 40.
1, utterance permission signal detector 402, received signal presence / absence detector 4
03, floor request detector 404, rising edge detector 4
05, a voice detector 409, a falling edge detector 411,
Floor request signal generator 412, AND circuits 406, 40
8, 410 and 413 and OR circuits 407, 414 and 4
16 and monostable multivibrator (hereinafter referred to as MM)
415 and a lamp driver 417.

Next, the operation of the system of this embodiment will be described with reference to the sequence diagram of FIG. 5 and the time chart of FIG. In this embodiment, the wireless terminal station (FIG. 5)
In FIG. 5, each of the mobile stations A, B, and C) has a unique number (indicated by I1, I2, and I3 in FIG. 5) and a group number of the group to which the own station belongs (in FIG. 5, mobile stations A, B). And C
Are assumed to belong to the same group of the group number GN), and a normal one-to-one call can be performed by a unique number. A group communication in a conference format can be performed between the stations.

That is, assuming that mobile station A has transmitted a call request for group number GN to radio base station 1 using a common control line (CSC channel), as shown in step 61 in FIG. Upon receiving this request signal, the base station 1 first makes a general call to all wireless terminal stations (here, mobile stations A, B and C) of the group number GN on the CSC channel (step 62 in FIG. 5). continue,
The radio base station 1 allocates a vacant channel among the plurality of radio channels as a communication channel, and transmits the communication channel to the mobile stations A, B, and C to notify the communication channel allocated by the CSC channel (FIG. 5). Step 63).

Upon receiving this transmission signal, the mobile stations A, B, and C of the group number GN make a call within the group using the assigned radio channel as a call channel (step 64 in FIG. 5). Here, in the present embodiment, since all the participating mobile stations A, B, and C of the group call mutually communicate using the same radio channel, the transmitting station is always one station, and when the talker is switched, As described above, collision is a problem.

Therefore, in this embodiment, this collision is avoided as follows. Of the mobile stations A, B, and C in the same group that make a group call, the mobile station that wants to transmit (speak) keeps pressing the floor request switch 37 shown in FIGS. When the floor request switch 37 is pressed, the floor request detector 404 in FIG. 4 detects the ON state of the floor request switch 37 and outputs a detection signal indicated by a in FIG. The detection signal a in FIG. 6 indicates that the high level is on, that is, the floor request switch 37 is pressed. The rising edge detector 405 outputs the detection signal a
When a rising edge is detected, a pulse having a short pulse width and a constant width as shown in FIG. 6C is output.

At this time, the mobile station is in either the transmission state or the reception state. When the speech permission is not given from the radio base station 1, it is always in the receiving state. FIG. 6F schematically shows the transmission / reception state of the mobile station, where the low level is in the reception (RX) state and the high level is in the transmission (TX) state.
Indicates a state.

FIG. 6B shows the output signal of the reception signal presence / absence detector 403 shown in FIG. 4, and the high level indicates the absence of the reception signal. When a high-level signal b indicating no reception signal is taken out from the reception signal presence / absence detector 403 of the mobile station that has made a floor request, the AND circuit 406 is set to the gate "open" state. As a result, the rising edge detection pulse c Is AND
The signal is supplied to an OR circuit 407 through a circuit 406, and further supplied to a floor request signal generation circuit 412, as shown in FIG.
As shown by d, a floor request signal including a number unique to the mobile station of the transmission source is generated and output.

The floor request signal d is the OR signal shown in FIG.
The signal is output to the TXBBP 47 shown in FIG. At this time, the output pulse c of the AND circuit 406 that has passed through the OR circuit 407 is supplied to the MM 415, which triggers on its fall to generate a high-level pulse for a predetermined time. The output pulse of the MM 415 is supplied to the modulator 49 of FIG. 3 through the OR circuit 414 as a control signal TX ON shown by e in FIG. 6, and makes the modulator 49 operable during the high level period. Further, a control signal CH SEL is supplied from the call connection control circuit 401 to the switch 48 and the local signal generation circuit 50, respectively.

As a result, the floor request signal extracted from the TXBBP 47 is supplied to the modulator 49 via the switch 48 in FIG. 3, where it is modulated by a predetermined modulation method and then transmitted by the U / C 51 to the transmission frequency band. Is converted to
The signal is amplified by the HPA 52 and further transmitted to the wireless base station 35 via the DPX 41 and the antenna 35 via a communication channel.

Thus, when requesting a floor,
When the floor request switch 37 is pressed, when the received signal is not detected, that is, when the transmission signal is not output from any of the wireless terminal stations (here, the mobile stations A, B and C), the floor request signal is transmitted to the wireless terminal. Transmitted to base station 1.

As described with reference to FIG. 2, the radio base station 1 decodes the floor request signal by the call connection control device 28, generates a floor permission signal to the transmission source, and transmits it to the outdoor communication device 3 and the antenna. 4.

The mobile station receives the transmission signal from the radio base station 1 with the antenna 35, down-converts it to a predetermined frequency by the D / C 43 via the DPX 41 and the LNA 42 in FIG.
Further, after being demodulated by the demodulator 44, it is supplied to the RXBBP 45 and the transmitter / receiver 36. At this time, when the mobile station that has made the floor request receives the above-mentioned floor permission signal, the floor permission signal is set to RXB.
It is detected by the speech permission signal detector 402 shown in FIG. 4 in the communication control circuit 40 via the BP 45. FIG. 6g shows this speech permission signal.

When the call permission signal g is input, the call connection processing circuit 401 shown in FIG. 4 generates a drive signal as shown by h in FIG. Lights up. As a result, the user is notified of the permission to speak, and is prompted to speak. While the speech is permitted, the voice signal input from the handset 36 of FIG. 3 is input to the voice detector 409 of FIG.
A high-level sound detection signal indicated by i is output.

The sound detection signal i is supplied to a falling edge detector 411 through an AND circuit 410, while A
The control signal TX ON is supplied to the modulator 49 of FIG. 3 via the ND circuit 413 and the OR circuit 414, respectively.
This is set to an operable state. FIG. 6E shows the control signal T
Indicates X ON.

The above audio signal is supplied to a modulator 49 via a splitter 46 and a switch 48, where it is modulated by a predetermined modulation method and then frequency-converted by a U / C 51 into a transmission frequency band. , Amplified by HPA52,
Further, the data is transmitted through the DPX 41 and the antenna 35 via a communication channel. Further, since this voice signal is transmitted from the radio base station 1 to all the mobile stations in the same group, it is needless to say that other mobile stations other than the own station can receive the voice signal of the speech. Since the own station also receives the voice signal of the own station, reliable communication can be confirmed.

If the user continues to speak even if the above-mentioned voice is interrupted, the speaking right request switch 37 can be kept on to secure the speaking right. That is, when the audio signal is interrupted, the output audio detection signal i of the audio detector 409 becomes low level, and this is detected by the falling edge detector 411 to generate a pulse having a constant and short pulse width. When the floor request switch 37 is kept on, the signal passes through the AND circuit 408 which is in the gate "open" state, and is further supplied to the floor request signal generation circuit 412 via the OR circuit 407, and the voice is now transmitted. A right request signal can be generated. When a speech permission signal to another mobile station is detected while the user is speaking, the state of the own station exits the speaking state and returns to the receiving state.

When the speech is completed, the speaking right request switch 37 is turned off. Then, the output signal a of the floor request detector 404 in FIG.
The output signal of the circuit 408 becomes low level, whereby the output signals of the OR circuits 407, 414 and 415 change to low level, and the modulator 49 is set to the transmission inhibition state and returns to the reception state.

Thereafter, when the speech permission signal detector 402 detects a speech permission signal to a radio terminal station other than the own station, the call connection processing circuit 401 uses the output signal of the speech permission signal detector 402 at that time. The low-level signal h is supplied to the driver 417, and the speech permission display 38 is turned off.

When the speech ends, each of the mobile stations A, B and C in the same group enters a state in which no signal is transmitted. Then, the intra-group call is continued. When the own station receives the speech permission signal addressed to the other station, the own station is set to the speech non-permission state.

In this way, the intra-group call is performed.
Thereafter, any of the mobile stations A, B, and C in the same group transmits a call end signal to the radio base station, thereby terminating the intra-group call. For example, as shown in step 65 of FIG. 5, when the mobile station A transmits the intra-group call termination signal to the radio base station 1, the mobile station A uses the communication channel used by the radio base station 1 for the intra-group call. Then, an end signal is transmitted to all the mobile stations A, B and C in the group as shown in step 66 of FIG. Thereafter, the wireless base station 1 releases the communication channel (step 67 in FIG. 5).

According to the present embodiment, a normal one-to-one call can be made using a unique number held by each wireless terminal station. For example, as shown in step 68 of FIG. 5, the mobile station B specifies the unique number I1 of the mobile station A and sets the radio base station 1
Makes a call request on the CSC channel, the radio base station 1 transmits a call signal on the CSC channel to the mobile station A having the unique number I1, as shown in step 69 of FIG.

Thereafter, the radio base station 1 transmits a channel assignment signal to each of the mobile stations A and B on the CSC channel (step 70 in FIG. 5). As a result, a call is made between the mobile stations A and B on the assigned channel (step 7 in FIG. 5).
1). At the time of this one-to-one communication, the call connection processing circuit 401 of the mobile station always sets the utterance permission signal TA after channel setting to a high level (ON) and generates a control signal TXON signal to the voice detector 409 based on the output voice detection signal. A voice activation (VOX) operation is performed.

At the end of the call, a clear signal is transmitted from any of the mobile stations to the radio base station 1 (step 72 in FIG. 5).
As a result, an end signal is transmitted to the mobile stations A and B using the communication channel assigned by the radio base station 1 (step 73 in FIG. 5). Thereafter, the wireless base station 1 releases the communication channel (step 74 in FIG. 5).

As described above, according to the present embodiment, the right to speak is managed by the call connection control device 28 of the radio base station 1, and therefore, in the intra-group call using the same radio channel, It is possible to avoid a collision at the time of change of the person. In a conventional MCA system that does not perform such management, as shown schematically in FIG. 7A, when mobile stations A, B, and C each perform intra-group communication,
In this case, a collision occurs in which transmission is performed simultaneously between the mobile stations A and B, but a collision occurs between the mobile stations B and C.

On the other hand, according to this embodiment, FIG.
As schematically shown in (B), even when the mobile stations A and B make a request for the right to speak almost at the same time as indicated by b1 and c1, respectively, when the mobile station A finishes speaking, the radio base station 1 As described with reference to FIG. 2, first-come first-served processing is performed, the floor request of the mobile station B having the earliest generation time of the floor request is recognized, and a voice permission signal is transmitted to the mobile station B as indicated by a black circle.

Similarly, the radio base station 1 also issues a request for the right to speak a1 and c2 of the mobile stations A and C immediately after the end of the speech of the mobile station B to the mobile station C in which the time of occurrence of the right to speak is earlier. The mobile station C transmits a speech permission signal to the mobile station B when the request for the right to speak immediately after the end of the speech of the mobile station C is only b2 from the mobile station B.

Therefore, according to the present embodiment, since the floor request signal is a signal having a very short duration, there is almost no occurrence of a collision, and the intra-group communication between a large number of mobile stations is caused by the collision. This can be done without fear of confusion and loop oscillation. Moreover, in this embodiment, since the mobile station that wants to speak can request the right to speak at any time, the intra-group call can be made in the almost complete conference mode.

Although the intra-group call between a plurality of mobile stations has been described above, the present embodiment also allows a call between a wireless terminal station and another public network. That is,
As shown in FIG. 1, a radio communication base station 1 is a communication device for an inter-region communication network (IACCU: Inter-Area Com).
ICUD29 which is a receiving unit and a ICUM30 which is a transmitting unit of the communication channel unit.
By connecting these to an arbitrary wireless channel demodulator 23-i and an arbitrary wireless channel modulator 26-i via the BSW 24, communication can be made between a wireless terminal station in the area and the outside.

Note that the radio terminal station 5 (fixed station 5a and mobile station 5b) is a full duplex communication device capable of transmitting and receiving at the same time.
Any single communication system that cannot receive data during transmission can be used. Further, the speech permission display 38 displays the speakable state by lighting, but it is also possible to use a display that displays the speakable state by blinking or by character display.

[0074]

As described above, according to the present invention,
The same communication is performed by transmitting a speech permission signal to only one radio terminal station by the management means of the radio base station among the plurality of radio terminal stations participating in the intra-group call and giving the right to speak. Even if a channel is used, collision of transmission signals at the time of speaker change can be avoided. You can make internal calls.

Also, no matter how many wireless terminal stations participate in the intra-group call, only one station has the floor, so that a wireless conference can be performed without fear of loop oscillation. Furthermore,
During a call within the group, the floor request signal transmission means sends
Since the floor request signal for acquiring the floor can be transmitted at any time, wireless communication within the group in the complete conference mode can be performed. .

Further, according to the present invention, since the transmission voice signal of the own station can be received and heard at the return of the radio base station, the intra-group call can be confirmed, and the radio conference can be reliably performed. Further, according to the present invention, the management means of the radio base station, when the speech request signals are transmitted from the plurality of radio terminal stations almost simultaneously by the priority processing circuit, permits only the earliest radio terminal station to speak. Since the first-come-first-served process for transmitting a signal can be performed, the floor can be reliably given to only one station, the occurrence of collision can be almost eliminated, and the intra-group communication can be performed more reliably.

Further, according to the present invention, while the own station is given the floor and the floor request switch is turned on, each time the interruption of the transmission signal of the own station is detected, the floor is requested. By generating the signal, the right to speak can be secured even if the transmission voice signal of the own station is interrupted, so that the actual intra-group communication can be performed.

Further, according to the present invention, since the radio base station can communicate between a radio terminal station in the area and a terminal station outside the area, the intra-group call can be made between the radio terminal station in the area and the radio terminal station outside the area. Can also be established with other terminal stations. In addition, since the above-mentioned intra-group communication uses the same communication channel, the frequency can be effectively used.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a wireless base station of the system of the present invention.

FIG. 2 is a configuration diagram of an embodiment of a main part of a wireless base station.

FIG. 3 is a configuration diagram of an embodiment of a wireless terminal station of the system of the present invention.

FIG. 4 is a circuit diagram of an embodiment of the communication control circuit of FIG. 3;

FIG. 5 is a sequence diagram for explaining the operation of the embodiment of the present invention.

FIG. 6 is a time chart for explaining the operation of FIG. 4;

FIG. 7 is a diagram for explaining the operation of the conventional and the present invention in an intra-group call in comparison.

FIG. 8 is a configuration diagram of an example of a regional wireless network to which the present invention can be applied.

FIG. 9 is a diagram illustrating an example of a frequency allocation of a wireless channel.

FIG. 10 is an explanatory diagram of various communication formats in a wireless base station.

FIG. 11 is a configuration diagram of an example of a main part of a conventional system.

[Explanation of symbols]

Reference Signs List 1 area wireless base station (ABS) 2 indoor communication device 3 outdoor communication device 4 base station antenna 5a fixed station 5b mobile station 22 common control line demodulator (CSCD) 23-1 to 23-n radio channel demodulator (RCU)
D) 24 Baseband processor (BSW) 25 Common control line modulator (CSCM) 26-1 to 26-n Radio channel modulator (RCU)
M) 28 Call connection control device (CCC) 36 Handset 37 Speaking right request switch 38 Speaking permission indicator 40 Communication control circuit 43 Frequency down converter (D / C: Down Conv)
er) 44 demodulator 45 reception baseband processor (RXBBP) 47 transmission baseband processor (TXBBP) 48 switch 49 modulator 50 local signal generation circuit 51 frequency up converter (U / C: Up Conver)
ter) 282 TRQ decoding-TA generation circuit 283 timer 401 call connection processing circuit 402 speech permission signal detector 403 received signal presence detector 404 floor request detector 405 rising edge detector 409 voice detector 411 falling edge detector 412 Voice request signal generator 417 Lamp driver

Claims (6)

(57) [Claims] 1. A wireless terminal station, which can wirelessly communicate with a wireless base station, accesses a wireless base station using a common control line during a call, and the wireless base station In a wireless communication system that allocates a free communication channel to a wireless terminal station that has made a call request using the common control line, each of the plurality of wireless terminal stations includes a unique number of the own station and a group to which the own station belongs. And the group number indicating
Means for accessing the wireless base station by using a common control line by using the unique number of the partner wireless terminal station to be communicated with or by using the group number; and a floor after accessing using the group number. Right request signal transmitting means for transmitting a right request signal requesting the wireless base station to the wireless base station; and transmitting a voice signal addressed to all other wireless terminal stations to which the own station belongs after obtaining the right to speak. Transmitting means, wherein when the wireless base station is accessed using the unique number, a call assigned to each of the wireless terminal stations calling the other wireless terminal station having the unique number. A communication channel that notifies a channel and, when accessed using the group number, notifies the same communication channel allocated to all wireless terminal stations having the same group number as the group number. Notifying means, and transmitting a talk permission signal to only one of the plurality of wireless terminal stations in the same group, which has the right to speak, during the intra-group call initiated by using the group number, and A wireless communication system comprising: a management unit for performing management. 2. The floor request signal transmitting means includes a floor request switch, a reception signal presence / absence detector for detecting the presence / absence of a reception signal, and the absence of the reception signal detected by the reception signal presence / absence detector. A transmission circuit for generating a floor request signal when the floor request switch is turned on, and a means for wirelessly transmitting the floor request signal from the generation circuit to the radio base station. A display for displaying a speech possible state, a speech permission signal detector for detecting the speech permission signal addressed to the own station, and a display when the speech permission signal is detected by the speech permission signal detector. 2. The wireless communication system according to claim 1, further comprising: control means for displaying the utterable state and making the transmitting unit operable, and means for wirelessly transmitting the voice signal of the own station via the transmitting unit. System. 3. The management means comprises: decoding means for receiving the floor request signal from the floor request signal transmitting means and decoding the request source thereof; and a unique terminal of the decoded request source wireless terminal station. 3. The wireless communication system according to claim 1, further comprising a speech permission signal transmission circuit that transmits a speech permission signal to the requesting wireless terminal station using a number. 4. The management means according to claim 3, further comprising a priority processing circuit for stopping reception and decoding of said floor request signal for a predetermined time after transmitting said floor permission signal. Wireless communication system. 5. The floor request signal transmitting means includes: a detection circuit for detecting the presence or absence of a transmission signal of the own station; a floor is given to the own station; and the floor request switch is turned on. 3. The wireless communication system according to claim 2, further comprising: a control circuit for causing the generation circuit to generate the floor request signal each time the disconnection of the transmission signal is detected by the detection circuit. 6. The radio base station, wherein: a plurality of radio channel demodulators to which a reception signal of a communication channel from the radio terminal station is input; and a common channel to which a reception signal of a common line from the radio terminal station is input. A control channel demodulator, a plurality of radio channel modulators for outputting a transmission signal of a communication channel to the radio terminal station, a common control line modulator for outputting a common channel transmission signal to the radio terminal station, An inter-region communication network receiving unit and an inter-region communication network transmitting unit for performing communication with the outside of the plurality of radio channel demodulation devices, and an arbitrary radio channel demodulation device among the plurality of radio channel demodulation devices and the plurality of radio channel modulation devices. Connection with any radio channel modulator, and connection between the inter-region communication network receiver and inter-region communication network transmitter and any of the radio channel demodulators and radio channel modulators. The wireless communication system according to claim 1, further comprising: a baseband switch that performs connection; and a call connection control device that controls connection of the baseband switch and includes the management unit.