JPH07107032A - Radio communication system - Google Patents

Abstract

PURPOSE:To provide a radio communication system capable of surely setting and using a communication channel for multi-address communication at all times. CONSTITUTION:When a multi-address communication request to mobile stations 111-113 is received from a present station or the other station, a base station 101 scans an idle channel, sets the channel CH1 for instance to be used for the multi-address communication and transmits channel transfer instruction signals including a group identification number G11 to the respective mobile stations inside a radio zone. When communication with the base station is possible by the specified channel CH1, the mobile station of a group 1 switches the communication channel to the channel and transmits channel transition completion signals to the base station. On the other hand, when the communication with the base station is impossible by the specified channel, channel transition failure signals are transmitted to the base station. The base station repeatedly instructs the transition of the communication channel until the channel, transition completion signals are obtained from all the mobile stations belonging to the group 1 and starts the multi-address communication when the channel transition of all the mobile station is confirmed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system, and more particularly to a wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations.

[0002]

2. Description of the Related Art In recent years, a radio communication system has been proposed in which identification signals are grouped to perform broadcast communication between a base station and a mobile station group.

An example of the above-mentioned conventional wireless communication system will be described below with reference to the drawings. Figure 11
FIG. 3 is a block diagram showing a configuration of a conventional wireless communication system disclosed in, for example, Japanese Patent Laid-Open No. 63-281529. In FIG. 11, a plurality of mobile stations 511 to 515 are present in the wireless zone 510 of the base station 501. The mobile stations 511 to 513 belong to the group 1 (group identification number is G51), and the mobile stations 514 and 5
15 is group 2 (group identification number is G52)
Belong to. Mobile station identification numbers PS511 to PS515 are assigned to the mobile stations 511 to 515, respectively.

FIG. 12 is a sequence chart showing a control sequence for broadcast communication in the wireless communication system of FIG. The broadcast communication operation in the conventional wireless communication system will be described below with reference to FIG.

For example, when the mobile station 511 of group 1 issues a start request for broadcast communication to itself, it sends a broadcast start request signal including the group identification number G51 of the group to which the mobile station belongs to the base station 501. . Accordingly, the base station 501
Sets a channel for broadcast communication and transmits a channel designation signal including a group identification number G51 to each of the mobile stations 511 to 513 belonging to group 1. In response to the channel designation signal, the mobile station 511 transmits a channel switching completion signal including the group identification number G51 and the mobile station identification number PS511 to the base station 501. Base station 501
When receiving the channel switching completion signal from the mobile station 511 which issued the broadcast start request signal, the group identification number G5
A broadcast communication start signal including 1 is transmitted to each mobile station 511 to 513 belonging to group 1. In addition, the base station 501
Transmits a transmission enable notification signal including the group identification number G51 to each of the mobile stations 511 to 513 belonging to group 1.

Next, when a transmission request is issued to the mobile station 511, the mobile station 511 transmits a transmission request signal including the group identification number G51 and the mobile station identification number PS511 to the base station 501. Upon receiving the transmission request signal, the base station 501 sends a transmission permission signal including the group identification number G51 and the mobile station identification number PS511 to each mobile station 511 belonging to the group 1.
To 513. In response to this transmission permission signal, the mobile station 511 becomes able to transmit data, and the other mobile stations 51
No. 2 and 513 are prohibited from being transmitted and can only be received. Next, the mobile station 511 transmits the data to the base station 501. The base station 501 broadcasts the received data to the mobile stations 511 to 513 belonging to the group 1. At this time, since the mobile stations 512 and 513 are in a receivable state on the same channel as the mobile station 511, they receive the data transmitted from the mobile station 511 via the base station 501. When the mobile station 511 issues a request to end transmission,
An end request signal including the group identification number G51 and the mobile station identification number PS511 is transmitted to the base station 501. Upon receiving this end request signal, the base station 501 again transmits the transmission enable notification signal including the group identification number G51 to each of the mobile stations 511 to 513 belonging to the group 1. As a result, the mobile stations 511 to 513 belonging to the group 1 are in the transmission enabled state.

Next, when a transmission request is issued to another mobile station 512, the group identification number G51 and the mobile station identification number PS
A transmission request signal including 512 is transmitted to the base station 501. The base station 501 accordingly responds to the group identification number G51.
And a transmission permission signal including the mobile station identification number PS512 are transmitted to the mobile stations 511 to 513 belonging to the group 1.
In response to this transmission permission signal, the mobile station 512 can transmit data, and the other mobile stations 511 and 513 are prohibited from transmitting and can only receive. As a result, the mobile station 51
1, 513 receive data transmitted from the mobile station 512 via the base station 501.

If a request for ending broadcast communication is issued to the mobile station 512, the mobile station 512 transmits a broadcast end request signal including the group identification number G51 to the base station 501. Upon receiving the broadcast end request signal, the base station 501 transmits a broadcast end signal including the group identification number G51 to each of the mobile stations 511 to 513 belonging to the group 1. As a result, the broadcast communication ends.

[0009]

However, in the above-described conventional wireless communication system, when performing broadcast communication, various problems as described below occur.

The first problem is that when a mobile station in a certain radio zone is located in an area overlapping with an adjacent radio zone, the mobile station receives radio waves from a base station in the adjacent radio zone. This is because there is a situation in which the base station corresponding to the local station cannot reliably receive a signal on the channel set for broadcast communication due to the interference.

The second problem is that in the broadcast communication state,
If transmission requests are simultaneously generated by a plurality of mobile stations, the transmission request signals to the base station collide with each other, which adversely affects the processing at the base station.

A third problem is that when the mobile station switches the communication mode from the broadcast communication to the one-to-one communication with the base station, the broadcast communication must be terminated and then the one-to-one communication must be requested again. This is because the switching process is troublesome and complicated because it has to be done.

A fourth problem is that when a mobile station located in the vicinity of an adjacent wireless zone continues to be in a receiving state during the broadcast communication, the channel set for the broadcast communication is in the adjacent wireless zone. It is difficult to reliably use the channel set for the broadcast communication because the base station determines that the channel is a free channel and is used for other communication.

The present invention has been made in view of the above various problems.
An object of the present invention is to provide a wireless communication system capable of reliably setting and using a communication channel for broadcast communication when performing broadcast communication between a master station and a slave station.

[0015]

The invention according to claim 1 is
A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, each slave station is classified into one or more groups in advance, and the master station identifies a group of slave stations. A channel identification instruction signal that includes a group identification number for transmitting an instruction to transition to the designated broadcast communication channel to all the subordinate stations in the wireless zone. , When receiving a channel shift instruction signal including a group identification number corresponding to the group to which the own station belongs, in order to shift the communication channel with the main station to the broadcast communication channel designated by the received channel shift instruction signal. And the channel transition completion signal transmitting means for transmitting the channel transition completion signal to the master station when the communication channel transition processing by the channel transition means is completed. When the master station further receives a channel shift completion signal from a slave station in the group identified by the group identification number, all the stations in the group are broadcast using the broadcast channel designated by the channel shift instruction signal. Each slave station is further provided with a broadcast communication signal transmitting means for transmitting a broadcast communication signal to a slave station, and each slave station further transmits a channel communication completion signal, and then uses the broadcast communication channel after the transition to broadcast from the master station. A broadcast communication signal receiving means for receiving a signal is provided.

The invention according to claim 2 is a wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each slave station is classified into one or more groups in advance. , The master station sends a candidate channel inspection request signal including a group identification number for identifying a group of slave stations and requesting inspection of availability of the designated broadcast channel candidate to all slave stations in the wireless zone. When receiving the candidate channel inspection request signal including the group identification number corresponding to the group to which the own station belongs, each slave station is provided with the candidate channel inspection request signal transmitting means for transmitting the candidate channel inspection request signal. Inspection means for inspecting whether or not a channel candidate for information communication can be used in the local station, and a candidate channel for transmitting an inspection result signal of a candidate channel for reporting the inspection result of the inspection means to the main station. And a 査 result signal transmitting means.

The invention according to claim 3 is a wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each slave station is classified in advance into one or more groups. , The master station includes the group identification number for identifying the group of slave stations and the slave station number for identifying the slave stations in the group, and gives the transmission permission individually to the slave stations in the broadcast communication. The transmission permission signal transmitting means for transmitting the transmission permission signal of No. 1 to all slave stations in the group is provided, and each slave station includes a group identification number corresponding to the group to which the slave station belongs and a slave station number corresponding to the slave station. When the permission signal is received, the data signal transmitting means for transmitting the data signal to the main station is provided.

The invention according to claim 4 is a wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each slave station is classified in advance into one or more groups. , Each slave station is provided with a channel switch request signal transmitting means for transmitting to the master station a channel switch request signal for requesting the switch of the broadcast communication channel, and the master station receives the channel switch request signal from the slave station in the broadcast communication. When receiving, includes a group identification number for identifying the group to which the slave station belongs,
And a channel switching instruction signal for instructing to switch the broadcast channel currently used by the slave stations in the group to another specified broadcast channel is sent to all slave stations in the group. Each slave station receives the channel switching instruction signal including the group identification number corresponding to the group to which it belongs, and switches the currently used broadcast communication channel to the corresponding channel switching instruction signal transmitting means. A broadcast communication channel switching means for switching to another broadcast communication channel designated by the instruction signal and receiving a signal from the main station is provided.

The invention according to claim 5 is a wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each slave station is classified in advance into one or more groups. , Each slave station is provided with a communication mode switching request signal transmitting means for transmitting to the master station a communication mode switching request signal for requesting to switch the communication mode from broadcast communication to one-to-one communication, and the master station is When a communication mode switching request signal is received from a slave station that is currently broadcasting, it includes a group identification number for identifying the group to which the slave station that issued the communication mode switching request signal and a slave station number corresponding to the slave station, and Each of the slave stations further includes a broadcast communication end signal transmitting means for transmitting a broadcast communication end signal for instructing the end of the broadcast communication to all slave stations in the group, and each slave station further corresponds to the group to which the slave station belongs. Knowledge When the broadcast communication end signal including the number and the slave station number corresponding to the own station is received, the one-to-one communication with the master station is executed by continuously using the communication channel used in the broadcast communication. Slave station side one-to-one communication execution means,
When a broadcast communication end signal containing a group identification number corresponding to the group to which the own station belongs and a slave station number other than the own station is received, the broadcast communication state with the master station is terminated and the system waits The master station further includes a master station side one-to-one communication execution means for performing one-to-one communication with the slave station which has issued the communication mode switching request signal.

The invention according to claim 6 is a wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each slave station is classified in advance into one or more groups. , Each slave station is provided with a communication mode switching request signal transmitting means for transmitting to the master station a communication mode switching request signal for requesting to switch the communication mode from broadcast communication to one-to-one communication, and the master station is When a communication mode switching request signal is received from a slave station that is broadcasting, it includes a group identification number for identifying the group to which the slave station that issued the communication mode switching request signal and a slave station number corresponding to the slave station, and A channel switching instruction signal that sends a channel switching instruction signal for instructing the slave station to switch the communication channel currently in use to another specified communication channel to all slave stations in the group. When receiving a channel switching instruction signal including a group identification number corresponding to the group to which the local station belongs and a dependent station number corresponding to the local station, each slave station switches the communication channel currently in use Slave station side 1: 1 that switches to another communication channel designated by the instruction signal and executes 1: 1 communication with the master station
The master station further includes a communication execution means, and the master station issues a communication mode switching request signal and a master station side one-to-one communication execution means that executes one-to-one communication with the slave station that has issued the communication mode switching request signal. And a broadcast communication continuation means for continuing the broadcast communication with other slave stations in the group to which the slave station belongs.

The invention according to claim 7 is a radio communication system for communicating between one or more master stations and a plurality of slave stations, wherein the master station sends out a busy tone signal indicating a communication channel currently in use. Is provided with a busy tone transmission request signal transmitting means for transmitting a busy tone transmission request signal to a slave station in the wireless zone, and when each slave station receives the busy tone transmission request signal, it transmits the communication channel being used for communication with the master station. A busy tone signal transmitting means for transmitting a busy tone signal by using it is provided.

[0022]

In the invention according to claim 1, when the master station transmits a channel shift instruction signal including a group identification number to each slave station in the wireless zone, each slave station of the corresponding group establishes a communication channel with the master station. , And shifts to the broadcast communication channel designated by the received channel shift instruction signal. Further, each slave station of the corresponding group transmits a channel shift completion signal to the master station when the communication channel shift processing in the own station ends. When the master station receives the channel shift completion signal from the slave station, the master station transmits the broadcast communication signal to all slave stations in the group by using the broadcast communication channel designated by the channel shift instruction signal. On the other hand, the slave station which has issued the channel shift completion signal receives the broadcast communication signal from the master station using the broadcast communication channel after the shift.

In the invention according to claim 2, when a candidate channel inspection request signal including a group identification number is transmitted from the master station to each slave station in the wireless zone, the slave stations of the corresponding group receive the candidate channel inspection request signal. It checks whether or not the designated broadcast communication channel candidate can be used in its own station, and transmits a candidate channel inspection result signal for reporting the inspection result to the main station.

In the invention according to claim 3, by transmitting a transmission permission signal including a group identification number and a slave station number from the master station to each slave station in the wireless zone, each of the groups in the broadcast communication is transmitted. The slave stations are individually given permission to transmit.

In the invention according to claim 4, when the slave station during the broadcast communication transmits a channel switching request signal to the master station,
The master station transmits a channel switching instruction signal including the group identification number to all slave stations in the wireless zone. When the slave station of the corresponding group receives the channel switching instruction signal,
The broadcast communication channel currently in use is switched to another broadcast communication channel designated by the channel switching instruction signal to receive a signal from the main station.

In the invention according to claim 5, when the slave station during the broadcast communication transmits a communication form switching request signal to the master station,
The master station transmits a broadcast communication end signal including the group identification number and the slave station number to all slave stations in the wireless zone. When the slave station of the corresponding group corresponds to its own station, the slave station continuously uses the communication channel used in the broadcast communication to execute one-to-one communication with the master station. On the other hand, if the slave station number does not correspond to the own station, the broadcast communication state with the master station is terminated and the system stands by.

In the invention according to claim 6, when the slave station during the broadcast communication transmits a communication mode switching request signal to the master station,
The master station transmits a channel switching instruction signal including the group identification number and the slave station number to all slave stations in the wireless zone. When the received slave station number corresponds to its own station, the slave stations in the corresponding group switch the communication channel currently in use to another communication channel specified by the channel switch instruction signal and pair it with the master station. 1 Execute communication. Also, the master station has a one-to-one correspondence with the slave station that has issued the communication mode switching request signal.
The communication is executed, and the broadcast communication is continued with other slave stations in the group to which the slave station that has issued the communication mode switching request signal belongs.

In the invention according to claim 7, by transmitting the busy tone transmission request signal from the master station to the slave stations in the wireless zone, the busy tone signal is transmitted from each slave station using the communication channel being used for communication with the master station. To send. As a result, the stations in the adjacent wireless zones are notified of the communication channel currently in use.

[0029]

(First Embodiment) FIG. 1 is a block diagram showing the configuration of a wireless communication system according to a first embodiment of the present invention. In FIG. 1, the wireless zone 11 of the base station 101
Within 0, for example, five mobile stations 111 to 115 are arranged. The mobile stations 111 to 113 are group 1
(Group identification number is G11), and mobile stations 114 and 115 belong to group 2 (group identification number is G12). In addition, the mobile stations 111 to 1
15 are mobile station identification numbers PS111 to PS, respectively.
115 is assigned. Furthermore, the base station 101
Is connected to the communication network 120 via a transmission path. In this embodiment, the base station 101 and the wireless zone 11
Digital communication using TDMA, for example, is adopted for communication with the mobile stations 111 to 115 within 0.

FIG. 2 is a block diagram showing a more detailed structure of the base station shown in FIG. In FIG. 2, the base station is
Line control unit 201, communication control unit 202, and input unit 20
3, output unit 204, modulation unit 205, and wireless control unit 2
06, a demodulation unit 207, and an antenna 208. The line control unit 201 includes the communication network 120 and the communication control unit 2.
It is inserted between the line No. 02 and the line No. 02 and controls the line connection state and switching. The communication control unit 202 includes a CPU, a ROM, a RAM and the like, and controls the communication state of the base station according to a sequence chart (see FIG. 4) described later. The input unit 203 is
It is composed of a keyboard, a microphone, etc., and inputs data and voice to the communication control unit 202. Output unit 204
Is composed of a magnetic disk device, a display device, a speaker, and the like, and stores, displays, and outputs data output from the communication control unit 202. Modulator 205
Modulates the transmission data output from the communication control unit 202 by a predetermined method (for example, quadrature phase modulation) and outputs the modulated transmission data to the wireless control unit 206. The radio control unit 206 includes the modulation unit 20.
5 has a function of transmitting the modulated data given from the antenna 5 on a carrier wave and transmitting from the antenna 208, and a function of receiving a signal in a predetermined frequency band from the high frequency signals induced in the antenna 208. The demodulation unit 207 demodulates the signal received by the wireless control unit 206 and gives it to the communication control unit 202. The wireless control unit 206 switches the communication channel in response to a channel switching instruction given from the communication control unit 202, and also transmits a transmission mode and a reception mode in response to a transmission / reception switching instruction given from the communication control unit 202. And can be switched.

FIG. 3 is a block diagram showing a more detailed structure of each mobile station shown in FIG. In FIG. 3, each mobile station includes a communication control unit 301, an input unit 302, and an output unit 30.
3, a modulation unit 304, a wireless control unit 305, and a demodulation unit 3
06 and an antenna 307. Communication control unit 3
01 includes a CPU, a ROM, a RAM and the like, and controls the communication state of the mobile station according to a sequence chart (see FIG. 4) described later. The input unit 302 inputs data and voice to the communication control unit 301. The output unit 303 stores, displays, and outputs the data output from the communication control unit 301. Modulation section 304 modulates the transmission data output from communication control section 301 by a predetermined method (for example, quadrature phase modulation) and outputs the result to radio control section 304. The radio control unit 305 has a function of transmitting the modulated data supplied from the modulation unit 304 on a carrier wave and transmitting from the antenna 307, and a function of receiving a signal in a predetermined frequency band from the high frequency signals induced in the antenna 307. . The demodulation unit 306
The signal received by the radio control unit 356 is demodulated and given to the communication control unit 301. The wireless controller 305
The communication channel is switched in response to the channel switching instruction given from the communication control unit 301, and the transmission mode and the reception mode are switched in response to the transmission / reception switching instruction given from the communication control unit 305.

FIG. 4 is a sequence chart showing a control sequence for broadcast communication in the wireless communication system according to the first embodiment of the present invention. The broadcast communication control operation in the wireless communication system according to the first embodiment will be described below with reference to FIG. Note that, although the following description shows the case where the broadcast communication is performed to the mobile stations of the group 1 for the sake of convenience, the same operation is performed when the broadcast communication is performed to the mobile stations of other groups. It is pointed out in advance that this will be done.

The base station 101 broadcasts to a mobile station belonging to the group 1 from a mobile station in the wireless zone 110 or from another station connected to the communication network 120 when a broadcast communication request is generated in the base station 101. When a communication request is received, a free channel is scanned to set a communication channel (for example, channel CH1) to be used for broadcast communication, and a channel shift instruction signal including a group identification number G11 is sent to the wireless zone using the broadcast channel. It transmits to each mobile station in 110. The broadcast channel is a channel that can be received by all mobile stations in the wireless zone 110.

Here, among the mobile stations in group 1, the mobile stations 111 and 112 are in a state of being connectable to the base station 101 on the channel CH1 set by the base station 101, but the mobile station 113 is not shown in the drawing. Base station 101 on channel CH1 due to radio wave interference from the wireless zone
Suppose that it is impossible to connect with. In this case, when the mobile stations 111 and 112 receive the channel transfer instruction signal including the group identification number G11, the group identification number G1 is received.
A channel shift completion signal including 1 and the identification numbers PS111 and PS112 of the local station is transmitted to the base station 101 on the channel CH1, and the standby state is changed to the broadcast communication state. On the other hand, the mobile station 113 transmits a channel transfer failure signal to the base station 101 on the broadcast channel and continues the standby state.
The mobile stations 111 to 113 sequentially transmit these signals to the base station at a timing determined for each mobile station in order to avoid collision of the channel transition completion signal or the channel transition failure signal. .

When the base station 101 receives the channel transfer failure signal from the mobile station 113, it scans an empty channel again to set a communication channel (for example, channel CH2) used for broadcast communication, and the group identification number G11. And transmits a channel shift instruction signal including the following to each mobile station in the wireless zone 110. At this time, all mobile stations 1 in group 1
When 11 to 113 can connect to the base station 101 on the channel CH2, the mobile stations 111 to 113 in the group 1
Transmits a channel transfer completion signal including the group identification number G11 and the identification numbers PS111 to PS113 of the own station to the base station 101 using the channel CH2.
The base station 101 includes all mobile stations 111 to 111 in the group 1.
When the channel shift completion signal from 113 is received, each mobile station belonging to the group 1 receives data from the station (including its own station) that has issued the broadcast communication request, using the channel CH2 set for broadcast communication. 111-113 (broadcast data).

As described above, according to the first embodiment, the base station 101 confirms that all the mobile stations in the group have moved to the designated broadcast communication channel, and Since the broadcast communication to each mobile station is started, it is necessary to surely perform the broadcast communication with all the mobile stations in the group by using the channel in which the radio interference from the adjacent wireless zone does not occur. You can

(Second Embodiment) FIG. 5 is a sequence chart showing a channel inspection control sequence for broadcast communication in a wireless communication system according to a second embodiment of the present invention. The channel inspection operation for broadcast communication in the second embodiment will be described below with reference to FIG. Since the hardware circuit configuration of the wireless communication system is the same as that of the first embodiment (FIGS. 1 to 3), the illustration is omitted.

First, the base station 101 sets a communication channel candidate (for example, the channel CH1) to be used for the broadcast communication, and sends a candidate channel inspection request signal including the group identification number G11 to the wireless zone using the broadcast channel. It transmits to each mobile station in 110. Each mobile station 1 belonging to group 1
When receiving the candidate channel inspection request signal including the group identification number G11 corresponding to the group 1 to which the own station belongs, each of the channels 11 to 113 inspects the candidate channel CH1 for a certain period of time,
If the radio wave interference level is equal to or lower than the predetermined threshold value, it is determined that the candidate channel CH1 can be used. If the radio wave interference level exceeds the predetermined threshold value, the candidate channel CH1 is not used. Judge as possible. next,
After inspecting the candidate channels, the mobile stations 111 to 113 sequentially transmit, to the base station 101, candidate channel inspection result signals including the availability results at the timing determined for each mobile station, and stand by.

After that, the base station 101 determines that each mobile station 111
If any one of the candidate channel inspection result signals from ~ 113 includes a determination result indicating that the channel cannot be used, another candidate channel is set and each mobile station 111 to 113 receives the candidate channel inspection request signal. Send again. On the other hand, when all of the candidate channel inspection result signals from the mobile stations 111 to 113 include the determination result indicating availability, the base station 101 transmits the channel shift instruction signal (see FIG. 4) to the candidate channel. , To each mobile station 111-113.
After that, the base station 101 confirms that the shift to the channel instructed by each of the mobile stations 111 to 113 is completed, and then starts the broadcast communication.

As described above, according to the second embodiment, whether or not the candidate channel can be used is inspected before starting the broadcast communication, so that the occurrence of radio wave interference with the adjacent radio zone. It is possible to set channels that are not available. After the inspection of the candidate channels is completed, the base station 10
If 1 transmits the channel shift instruction signal of FIG. 4 to each mobile station, it is possible to prevent a situation in which each mobile station repeatedly shifts channels. That is, in the first embodiment,
When the transfer to the channel instructed from the base station 101 fails in any mobile station, the channel transfer instruction signal to the next channel is the channel concerned to the mobile station that has successfully transferred to the instructed channel, Further, since the mobile station that has failed to switch to the instructed channel must be transmitted on the broadcast channel, it is necessary to perform troublesome control on the base station side. However, since the inspection of the candidate channels in the second embodiment is always performed on the broadcast channel, it is not necessary to perform such troublesome control.

(Third Embodiment) FIG. 6 is a sequence chart showing a transmission control sequence during broadcast communication in a wireless communication system according to a third embodiment of the present invention. Less than,
The transmission control operation at the time of broadcast communication in the third embodiment will be described with reference to FIG. Since the hardware circuit configuration of the wireless communication system is the same as that of the first embodiment (FIGS. 1 to 3), the illustration is omitted.

Each mobile station 11 already belonging to group 1
It is assumed that 1 to 113 are in the broadcast communication state using, for example, the channel CH1. The base station 101 uses the channel CH1 set for broadcast communication to transmit a transmission permission signal including the group identification number G11 and the mobile station identification number PS111, and the mobile station 11 belonging to the group 1 in the broadcast communication state.
1 to 113. Upon receiving the transmission permission signal including the mobile station identification number PS111 corresponding to the mobile station 111, the mobile station 111 can transmit the signal to the base station 101 using the channel CH1. Therefore, the mobile station 111 transmits a data signal including the group identification number G11 and the mobile station identification number PS111 to the base station 101 if there is a transmission request to the base station 101 (data transmission). On the other hand, since the other mobile stations 112 and 113 belonging to the group 1 receive the transmission permission signal including the mobile station identification number PS111 other than the own station, the transmission from the own station is prohibited and the base station using the channel CH1 is used. 10
Reception of the signal from 1 is continued.

Next, the base station 101 transmits a transmission permission signal including the group identification number G11 and the mobile station identification number PS112 to the mobile stations 111 to 113 using the channel CH1. At this time, the base station 101 transmits the transmission permission signal and the data signal received from the mobile station 111 to each of the mobile stations 111 to 113. When the mobile station 112 receives the transmission permission signal including the mobile station identification number PS112 corresponding to the mobile station 112, the mobile station 112 is in the transmission enabled state, but since the mobile station 112 has no transmission request, the mobile station 112 sets the group identification number G11 and the mobile station identification number PS112. A response signal including the same is transmitted to the base station 101 using the channel CH1 (response). Meanwhile, group 1
The other mobile stations 111 and 113 belonging to the base station 101 receive the transmission permission signal including the mobile station identification number PS112 other than their own station, prohibit the transmission of their own station, and use the channel CH1 to transmit the base station 101 to the base station 101. Continue to receive signals from. Therefore, the mobile stations 112 and 113 will receive the data signal transmitted from the mobile station 111 via the base station 101. As a result, the mobile station 111 and the mobile station 112,
So-called press talk (one-to-many) communication is realized with 113.

Next, the base station 101 transmits a transmission permission signal including the group identification number G11 and the mobile station identification number PS113 to the mobile stations 111 to 113 using the channel CH1. As a result, the transmission right is given to the mobile station 113. Accordingly, the mobile station 113, if there is a transmission request to the mobile station 113, receives the group identification number G11 and the mobile station identification number PS11.
A data signal including 3 is transmitted to the base station 101 (data transmission). This data signal has a group identification number G11.
Together with the transmission permission signal including the mobile station identification number PS111 and the channel CH1 from the base station 101 to the mobile station 1
11 to 113 are transmitted. As a result, the mobile station 11
3 and the mobile stations 111 and 112, press talk (1
(To many) communication is realized.

After that, the base station 101 uses the mobile stations 111 to 1
Transmission permission is sequentially given to 13 (polling control). This enables press talk (one-to-many) communication from any mobile station in the group.

As described above, according to the third embodiment, the base station 101 transmits the transmission permission signal including the mobile station identification number to each mobile station in the group in order and the transmission of each mobile station. Since it is controlled, each mobile station can access the base station 10
It is possible to avoid the collision of the signals transmitted to the unit 1. As a result, it is possible to reliably transmit and receive signals using the channel set for broadcast communication. Further, by including data in the transmission permission signal, press talk (one-to-many) communication can be performed between the mobile station to which transmission permission is given in the group and another mobile station.

(Fourth Embodiment) FIG. 7 is a sequence chart showing a channel switching control sequence at the time of broadcast communication in the wireless communication system of the fourth embodiment of the present invention. The channel switching operation at the time of broadcast communication in the fourth embodiment will be described below with reference to FIG. The hardware circuit configuration of the wireless communication system is the same as that of the first embodiment (see FIG.
Up to FIG. 3), the illustration is omitted.

Now, the mobile stations 111 to 111 belonging to the group 1
It is assumed that 113 is in a broadcast communication state using the channel CH1. In this state, for example, the mobile station 111 belonging to the group 1 receives a signal from the base station 101 on the channel CH1 set for broadcast communication due to radio wave interference from an adjacent wireless zone (not shown). Assume that it is difficult to continue. In this case, the mobile station 111 receives the group identification number G1 from the base station 101.
1 and a mobile station identification number PS111 are received and transmission permission is given, the group identification number G11
And a channel switching request signal including the mobile station identification number PS111 using the channel CH1 set for broadcast communication,
It transmits to the base station 101.

The base station 101 has a group identification number G11.
When a channel switching request signal including the mobile station identification number PS111 is received, an empty channel is scanned again to set a channel CH2 that can be used for broadcast communication, and a channel switching instruction signal including the group identification number G11 is sent to the channel CH.
1 is used to transmit to the mobile stations 111 to 113 belonging to group 1. When the mobile stations 111 to 113, which are connected to the base station 101 through the channel CH1 and are in the broadcast communication state, receive the channel switching instruction signal in which the group identification number G11 corresponding to the group 1 to which the local station belongs is set, The switching process is executed, and the base station 1
01 is reconnected to continue the broadcast communication state.

Next, the base station 101 transmits a signal from its own station or another station which has issued the broadcast communication request to the mobile stations 111 to 113 belonging to group 1 using the channel CH2 (data broadcast). ) Do. Accordingly, the mobile stations 111 to 113 in the broadcast communication state receive the signal from the base station 101.

As described above, according to the fourth embodiment, when the base station 101 receives the channel switching request signal from the mobile station in the broadcast communication state, the base station 101 and the mobile station group are connected to each other. Since the broadcast communication channel used in 1 is switched, even if the signal reception status of the mobile stations in the group deteriorates, the broadcast communication can always be continued in a good condition.

(Fifth Embodiment) FIG. 8 is a sequence chart showing a communication form switching control sequence during broadcast communication in a wireless communication system according to a fifth embodiment of the present invention. Hereinafter, with reference to FIG. 8, the communication mode switching operation during the broadcast communication in the fifth embodiment will be described. The hardware circuit configuration of the wireless communication system is the same as that of the first embodiment (see FIG.
Up to FIG. 3), the illustration is omitted.

Now, the mobile stations 111 to 111 belonging to the group 1
It is assumed that 113 is in a broadcast communication state using the channel CH1. In this state, it is assumed that, for example, the mobile station 111 belonging to the group 1 issues a request for switching to one-to-one communication with the station (including the base station 101) that has issued the broadcast communication request. In this case, the mobile station 111 is the base station 101.
When the transmission permission is given from (for example, when the transmission permission signal including the group identification number G11 and the mobile station identification number PS111 is received), the communication mode switching request signal including the group identification number G11 and the mobile station identification number PS111 of the own station. Are transmitted to the base station 101 using the channel CH1 set for broadcast communication.

The base station 101 has a group identification number G11.
When the communication form switching request signal including the mobile station identification number PS111 and the mobile station identification number PS111 is received, the broadcast communication end signal including the group identification number G11 and the mobile station identification number PS111 is transmitted to the channel C.
Mobile stations 111 to 113 belonging to group 1 using H1
Send to. Mobile stations 112, 113 in a broadcast state
When receiving the broadcast end signal including the group identification number G11 corresponding to the group 1 to which the own station belongs, disconnects the connection with the base station 101 and shifts to the standby state. on the other hand,
Since the mobile station 111 includes the mobile station identification number PS111 of its own station in the broadcast communication end signal, the mobile station 111 transits to the one-to-one communication state, and if there is a transmission request to the mobile station 111, a channel is sent to the base station 101. A data signal is transmitted using CH1 (data transmission). Similarly, the base station 101 also transmits a data signal to the mobile station 111 using the channel CH1 (data transmission) if the base station 101 has a transmission request. As a result, the mobile station 11
1 and the base station 101 (or another station via the base station 101) perform one-to-one communication.

When the base station 101 receives the broadcast communication end request from the station (including the base station 101) which has issued the broadcast communication request or the one-to-one communication end request from the mobile station 111,
A one-to-one communication end signal including the mobile station identification number PS111 is transmitted to the mobile station 111. When the mobile station 111 receives the one-to-one communication end signal including the mobile station identification number PS111 of the mobile station 111, the mobile station 111 disconnects from the base station 101 and transits to the standby state.

As described above, according to the fifth embodiment, when the base station 101 receives a communication form switching request from a mobile station that is in broadcast communication, it continuously uses the channel that is being used for broadcast communication. Since the base station 101 is used to perform one-to-one communication with the mobile station, the mobile station is the base station 101.
It is possible to switch the communication mode without disconnecting the connection with.

(Sixth Embodiment) FIG. 9 is a sequence chart showing a communication form switching control sequence during broadcast communication in a wireless communication system according to a sixth embodiment of the present invention. Hereinafter, with reference to FIG. 9, the communication mode switching operation during the broadcast communication in the sixth embodiment will be described. The hardware circuit configuration of the wireless communication system is the same as that of the first embodiment (see FIG.
Up to FIG. 3), the illustration is omitted.

Now, the mobile stations 111 to 111 belonging to the group 1
It is assumed that 113 is in a broadcast communication state using the channel CH1. In this state, it is assumed that, for example, the mobile station 111 belonging to the group 1 issues a request for switching to one-to-one communication with the station (including the base station 101) that has issued the broadcast communication request. In this case, the mobile station 111 is the base station 101.
Group identification number G11 and mobile station identification number PS1 from
When the transmission permission signal including 11 is given and the transmission permission is given, the group identification number G11 and the mobile station identification number P of the own station are given.
A communication mode switching request signal including S111 is transmitted to the base station 101 using the channel CH1 set for broadcast communication. At this time, the mobile station 111 sets, in the communication mode switching signal, an instruction to continue or end the broadcast communication state of the other mobile stations 112 and 113 in the group 1.

Here, the mobile station 111 is the other mobile station 11
The operation when the continuation of the broadcast communication state of 2,113 is instructed will be described. In this case, when the base station 101 receives the communication form switching request signal including the group identification number G11 and the mobile station identification number PS111, it scans an empty channel and sets the channel CH2 used for one-to-one communication, and the group identification is performed. A channel switching instruction signal including the number G11 and the mobile station identification number PS111 is transmitted to the mobile station 111 using the channel CH1. When the mobile station 111 receives the channel switching instruction signal including the group identification number G11 and the mobile station identification number PS111, it sets the communication channel to the channel C.
It switches to H2, reconnects with the base station 101, and transits to a one-to-one communication state. Therefore, the mobile station 111 transmits a data signal to the base station 101 using the channel CH2 (data transmission) if the mobile station 111 has a transmission request. In addition, the base station 101 starts transmitting and receiving signals (one-to-one communication) with the mobile station 111, and issues a broadcast communication request (base station 1
Data signals (including 01) are transmitted to the mobile station 111 using the channel CH2. On the other hand, the mobile stations 112 and 113 in the broadcast communication state discard the channel switching instruction signal including the mobile station identification number PS111 other than their own station and continue the broadcast communication state, and use the channel CH1 to transmit the base station 10 to the base station 10.
Reception of the signal from 1 is continued.

Next, the mobile station 111 moves to another mobile station 112,
An operation when the end of the broadcast communication state of 113 is instructed will be described. In this case, when the base station 101 receives the communication form switching request signal including the group identification number G11 and the mobile station identification number PS111, the broadcast communication end signal is received as in the fifth embodiment (see FIG. 8). By mobile station 1
The broadcast communication with 12, 113 is ended, and the one-to-one communication with the mobile station 111 is started using the channel CH1 used for the broadcast communication.

After that, the base station 101 requests the broadcast communication end request from the station which has issued the broadcast communication request, or the mobile station 111.
When receiving the one-to-one communication end request from (or the base station 101), the one-to-one communication end signal including the mobile station identification number PS111 is transmitted to the mobile station 111 using the channel CH2. The mobile station 111 has its own mobile station identification number PS1.
When the 1: 1 communication end signal including 11 is received, the base station 1
The connection with 01 is disconnected and the state transits to the standby state.

Next, when the base station 101 issues a broadcast communication end request in its own station or when it receives a broadcast communication end request from the mobile stations 112 and 113 which continue the broadcast communication, the base station 101 The broadcast communication end signal including the identification number G11 is transmitted to the mobile stations 112 and 113 belonging to the group 1. The mobile stations 112 and 113 in the broadcast communication state have the group identification number G1 corresponding to the group 1 to which their own stations belong.
When the broadcast communication end signal including 1 is received, the base station 101
Disconnect the connection with and transit to the standby state.

As described above, according to the sixth embodiment, when a mobile station that is broadcasting is transmitting a communication mode switching signal to the base station 101, the communication mode switching signal within the same group is included in the communication mode switching signal. Since the necessity of continuing the broadcast communication state of another mobile station is designated, even if the own station and the base station 101 start one-to-one communication, other mobile stations in the same group may be used as necessary. Mobile station can continue the broadcast communication with the base station 101.

(Seventh Embodiment) FIG. 10 shows a seventh embodiment of the present invention.
5 is a sequence chart showing a busy tone transmission control sequence at the time of broadcast communication in the wireless communication system of the embodiment of FIG. The busy tone transmission control operation during the broadcast communication in the seventh embodiment will be described below with reference to FIG. The hardware circuit configuration of the wireless communication system is the first
Since it is the same as the embodiment (FIGS. 1 to 3), the illustration is omitted.

Now, the mobile stations 111 to 111 belonging to the group 1
It is assumed that 113 is in a broadcast communication state using the channel CH1. In this state, the base station 101 transmits a busy tone transmission request signal including the group identification number G11 to the mobile stations 111 to 113 belonging to the group 1 in the broadcast communication state by using the channel CH1. Mobile station 111
When receiving the busy tone transmission request signal including the group identification number G11, the to 113 transmit the busy tone signals all at once using the channel CH1 being used for the broadcast communication. As a result, the base station or mobile station in the adjacent wireless zone (not shown) is notified that the channel CH1 is being used. Therefore, a base station or a mobile station in an adjacent wireless zone (not shown) receives a busy tone signal from the mobile stations 111 to 113 at the time of scanning an empty channel and at the time of inspecting a specific channel, and the channel CH1 already has an adjacent wireless zone. It is being used in the zone, and it is determined that it cannot be used for communication of its own station. Note that the base station 101 transmits a busy tone transmission request signal to the mobile station regularly or irregularly.

As described above, according to the seventh embodiment, by transmitting the busy tone signal from each mobile station regularly or irregularly, the radio wave from the base station 101 does not reach the adjacent radio zones. It is also possible to notify the station of the channel usage state, and it is possible to prevent radio wave interference due to channel competition between adjacent wireless zones.

Although some embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the technical contents of the above embodiments. That is, the following is also included in the present invention.

In the first embodiment (see FIG. 4), the base station 1
01 starts data broadcasting after receiving the channel change completion signal from all the mobile stations in the group, but the number of mobile stations of a predetermined ratio or more, or the channel change from a specific mobile station The data broadcasting may be started after receiving the completion signal.

The first (or second) embodiment (see FIG. 4)
(Or FIG. 5), when the base station 101 receives the broadcast communication request, the base station 101 transmits the channel shift instruction signal (or the candidate channel check request signal) only once to the mobile station in the standby state. However, in the case where the mobile station is equipped with a mechanism for periodically (battery saving cycle) receiving a signal from the base station 101 in order to save power consumption, in order to reliably transmit the signal to the mobile station. Alternatively, the channel shift instruction signal (or the candidate channel inspection request signal) may be transmitted a plurality of times. In addition, in the first (or second) embodiment, in order to avoid signal collision with the base station 101, each mobile station sequentially performs a channel shift completion signal (or channel check) at a predetermined timing. The result signal) is transmitted to the base station 101, but when the base station 101 can simultaneously receive signals of a plurality of channels, each mobile station simultaneously transmits a channel transition completion signal (or a channel check result signal) on a different channel. You may make it transmit.

In the second embodiment, the base station 10
The inspection condition may be stored in the candidate channel inspection request signal transmitted from 1 to each mobile station, and the inspection time and the radio wave interference determination condition may be set accordingly.

Further, in the third embodiment (see FIG. 6), the base station 101 stores the data signal sent from the mobile station to which the transmission permission is given, in the transmission permission signal for the next mobile station. However, the data included in the signal from the station (including the base station 101) that issued the broadcast communication request may be stored in the transmission permission signal to broadcast the data. Further, in the third embodiment, the base station 101 sequentially gives the transmission permission to each mobile station in the same group.
The base station 10 responds to a random transmission request from each mobile station.
1 may give a transmission permission at any time.

In the fourth embodiment (see FIG. 7), when the mobile station receives the transmission permission signal from the base station 101, the mobile station uses the channel for which the channel switching request signal is set for the broadcast communication, I tried to send to the base station 101,
When a control channel or the like capable of transmitting and receiving signals between the base station 101 and the mobile station at any time is provided, a channel other than the channel set for broadcast communication (for example, a control channel) is used. The switching request signal may be transmitted to the base station 101.

The fifth (or sixth) embodiment (FIG. 8)
(Or FIG. 9)), the base station 101 switches the communication mode to the one-to-one communication when receiving the communication mode switching request signal from the mobile station in the broadcast communication state. When a request to switch to one-to-one communication is made at a station, or a mobile station that has issued a broadcast communication request sends a communication mode switch request signal containing the mobile station identification number of the mobile station that is the communication partner station in the same group. If received, one-to-one communication may be started.

In the sixth embodiment, the base station 101
Has decided to switch the communication channel with the mobile station that issued the communication mode switch signal from the channel being used for broadcast communication to another channel when switching the communication mode while maintaining the broadcast communication state. However, conversely, by transmitting a channel switching instruction signal to the mobile stations in the group that continue the broadcast communication, the one-to-one communication is performed using the channel being used for the broadcast communication. May be.

In the seventh embodiment (see FIG. 10),
The base station 101 is configured to transmit the busy tone transmission request signal by including the group identification number. However, by including the mobile station identification number in place of the group identification number, the base station 101 determines whether it is in the one-to-one communication state or the broadcast communication state. Regardless, a specific mobile station in the wireless zone may be requested to transmit the busy tone signal.

In each of the above embodiments, the radio communication system for performing the broadcast communication between the base station and a plurality of mobile stations has been shown, but the present invention is not limited to this, and the main stations ( (Including both mobile and stationary types)
The present invention can be applied to a wireless communication system that performs broadcast communication between a slave station and a plurality of slave stations (including both mobile type and stationary type).

[0077]

According to the first aspect of the present invention, the master station confirms that all slave station communication channels in the group have been switched to the designated broadcast communication channel, and then transmits to each slave station of the group. Since the broadcast communication is started, it is possible to reliably perform the broadcast communication with all the slave stations in the group by using the channel in which the radio wave interference from the adjacent wireless zone does not occur.

According to the invention of claim 2, before starting the broadcast communication, each slave station inspects whether or not the candidate channel for broadcast communication can be used. It is possible to surely set the broadcast communication channel in which the occurrence of the error does not occur.

According to the third aspect of the present invention, the master station sequentially gives the transmission right to each slave station in the group in the broadcast communication. Therefore, the transmission signal from each slave station to the master station collides. You can avoid doing it. As a result, it is possible to reliably send and receive signals using the communication channel set for broadcast communication. Also,
By including data in the transmission permission signal, press talk (one-to-many) communication can be performed between the slave station to which transmission permission is given in the group and another slave station.

According to the invention of claim 4, when the slave station in the broadcast communication issues a channel switching request, the broadcast communication channel used between the master station and the slave station group is switched. Therefore, even if the reception status of the signal in the slave stations in the group deteriorates, the broadcast communication can always be continued in a good condition.

According to the invention of claim 5, when the communication mode switching request is issued from the slave station in the broadcast communication, the channel used in the broadcast communication is continuously used and the master station and the slave station concerned Since the one-to-one communication is performed between the slave stations, the slave station can switch the communication mode without disconnecting the connection with the master station.

According to the invention of claim 6, when the communication mode switching request is issued from the slave station in the broadcast communication, the communication channel between the slave station and the master station is separated from the currently used broadcast communication channel. Since the one-to-one communication is started by switching to the channel No. 1, the broadcast communication between the master station and the other slave stations in the same group can be continued as it is.

According to the invention of claim 7, since the busy tone signal is transmitted from each slave station in response to a request from the master station, it is possible to transmit to a station in an adjacent radio zone where the radio wave from the master station does not reach. Also, it becomes possible to notify the usage status of the channel, and it is possible to prevent radio wave interference due to channel competition between adjacent wireless zones.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a wireless communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a more detailed configuration of a base station in FIG.

3 is a block diagram showing a more detailed configuration of a mobile station in FIG.

FIG. 4 is a sequence chart showing a broadcast communication control sequence in the first embodiment of the present invention.

FIG. 5 is a sequence chart showing a channel inspection control sequence in the second embodiment of the present invention.

FIG. 6 is a sequence chart showing a transmission permission switching control sequence in the third embodiment of the present invention.

FIG. 7 is a sequence chart showing a channel switching control sequence according to a fourth embodiment of the present invention.

FIG. 8 is a sequence chart showing a communication form switching control sequence according to a fifth embodiment of the present invention.

FIG. 9 is a sequence chart showing a communication form switching control sequence according to a sixth embodiment of the present invention.

FIG. 10 is a sequence chart showing a busy tone transmission control sequence according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram showing an example of a configuration of a conventional wireless communication system.

FIG. 12 is a sequence chart showing a broadcast communication control sequence in a conventional wireless communication system.

[Explanation of symbols]

 101 ... Base station 110 ... Wireless zone 111-115 ... Mobile station 120 ... Communication network 201 ... Line control unit 202, 301 ... Communication control unit 203, 302 ... Input unit 204, 303 ... Output unit 205, 304 ... Modulation unit 206, 305 ... Radio control section 207, 306 ... Demodulation section 208, 307 ... Antenna

Claims (7)

[Claims] 1. A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each of the slave stations is classified into one or more groups in advance, and the master station is , A channel transition instruction signal including a group identification number for identifying a group of the slave stations and transmitting a channel transition instruction signal for instructing a transition to a designated broadcast channel to all slave stations in the wireless zone. When each of the slave stations receives the channel shift instruction signal including the group identification number corresponding to the group to which the own station belongs, the slave station specifies a communication channel with the master station by the received channel shift instruction signal. Channel shifting means for shifting to the broadcast communication channel that has been set up, and when the processing of shifting the communication channel by the channel shifting means is completed, the channel shifting to the main station is performed. And a channel shift completion signal transmitting means for transmitting a row completion signal, wherein the master station further receives a channel shift completion signal from a slave station in a group identified by the group identification number, and specifies the channel shift instruction signal. The broadcast communication signal transmitting means for transmitting the broadcast communication signal to all slave stations in the group using the broadcast communication channel is provided, and each slave station further shifts after transmitting the channel shift completion signal. A wireless communication system comprising: a broadcast communication signal receiving means for receiving the broadcast communication signal from the master station using the subsequent broadcast communication channel. 2. A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each of the slave stations is classified into one or more groups in advance, and the master station is A candidate channel inspection request signal including a group identification number for identifying a group of the slave stations and requesting inspection of availability of a designated broadcast communication channel candidate is transmitted to all slave stations in the wireless zone. Upon receiving the candidate channel inspection request signal including the group identification number corresponding to the group to which the slave station belongs, each slave station is provided with a candidate channel inspection request signal transmission means, and the slave station broadcasts the broadcast signal designated by the candidate channel inspection request signal. Inspection means for inspecting whether or not the communication channel candidate can be used in the own station, and a candidate channel inspection result signal for reporting the inspection result of the inspection means is transmitted to the main station. A wireless communication system, comprising: complementary channel inspection result signal transmitting means. 3. A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each of the slave stations is classified into one or more groups in advance. , A transmission permission including a group identification number for identifying the group of the slave stations and a slave station number for identifying the slave stations in the group, and for individually permitting the slave stations in the broadcast communication to transmit. The transmission permission signal transmitting means for transmitting a signal to all the slave stations in the group is provided, and each of the slave stations includes the transmission permission including the group identification number corresponding to the group to which the slave station belongs and the slave station number corresponding to the slave station. A wireless communication system comprising data signal transmitting means for transmitting a data signal to the main station when receiving a signal. 4. A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each of the slave stations is classified into one or more groups in advance, and each of the slave stations is A channel switching request signal transmitting means for transmitting a channel switching request signal for requesting switching of the broadcast communication channel to the master station, wherein the master station sends the channel switch request signal from a slave station in the broadcast communication. When received, it includes a group identification number for identifying the group to which the slave station belongs, and switches the broadcast communication channel currently used by the slave stations in the group to another designated broadcast communication channel. A channel switching instruction signal transmitting means for transmitting a channel switching instruction signal for instructing to all slave stations in the group, each slave station further corresponding to a group to which its own station belongs. When the channel switching instruction signal including the group identification number to be received is received, the currently used broadcasting communication channel is switched to another broadcasting channel designated by the channel switching instruction signal and the A wireless communication system comprising broadcast communication channel switching means for receiving a signal. 5. A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each of the slave stations is classified into one or more groups in advance, and each of the slave stations is A communication mode switching request signal transmitting means for transmitting to the main station a communication mode switching request signal for requesting switching of the communication mode from the broadcast communication to the one-to-one communication. When the communication mode switching request signal is received from the slave station in communication, the group ID number for identifying the group to which the slave station that issued the communication mode switching request signal belongs and the slave station number corresponding to the slave station are included, and the broadcast A broadcast communication end signal transmitting means for transmitting a broadcast communication end signal for instructing the end of communication to all slave stations in the group is provided, and each slave station further includes a group corresponding to the group to which the slave station belongs. When the broadcast communication end signal including the group identification number and the slave station number corresponding to its own station is received, the pair of communication with the master station is continuously performed by using the communication channel used in the broadcast communication. When receiving the broadcast communication end signal including the slave station side one-to-one communication executing means for executing one communication and the group identification number corresponding to the group to which the own station belongs and the slave station numbers other than the own station, A broadcast communication state terminating means for terminating a broadcast communication state between the master station and the slave station which has issued the communication mode switching request signal, and the master station further executes a one-to-one communication with the slave station. A wireless communication system comprising station-to-point one-to-one communication execution means. 6. A wireless communication system for performing broadcast communication between one or more master stations and a plurality of slave stations, wherein each of the slave stations is classified into one or more groups in advance, and each of the slave stations is A communication mode switching request signal transmitting means for transmitting to the main station a communication mode switching request signal for requesting switching of the communication mode from the broadcast communication to the one-to-one communication. When the communication mode switching request signal is received from the slave station in communication, the slave station includes a group identification number for identifying the group to which the slave station that has issued the communication mode switching request signal and a slave station number corresponding to the slave station, and Sends a channel switching instruction signal for instructing to switch the communication channel currently in use to another specified communication channel to all slave stations in the group. Each of the slave stations further includes a transmitter, and when each of the slave stations receives the channel switching instruction signal including the group identification number corresponding to the group to which the slave station belongs and the slave station number corresponding to the slave station, the communication channel currently in use is The slave station side one-to-one communication execution means for switching to another communication channel designated by the channel switching instruction signal and executing one-to-one communication with the master station is provided, and the master station further switches the communication mode. Between the master station side one-to-one communication executing means for executing one-to-one communication with the slave station which issued the request signal, and another slave station in the group to which the slave station which issued the communication mode switching request signal belongs. A wireless communication system, comprising: a broadcast communication continuation unit that continues broadcast communication. 7. A wireless communication system for communicating between at least one master station and a plurality of slave stations, wherein the master station requests busy tone signal transmission indicating a communication channel currently in use. A request signal, comprising a busy tone transmission request signal transmitting means for transmitting to the slave station in the wireless zone, each slave station, when receiving the busy tone transmission request signal, using the communication channel in use for communication with the master station. A wireless communication system, comprising: busy tone signal transmitting means for transmitting the busy tone signal.