JP2000013302A - Emergency radio system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent periodical breaks of the speech and to easily listen to the speech by preparing a constitution that a control office transmits a switch signal to a busy mobile station to switch the receiving channel of every station to a control channel only at the time when a simultaneous notification or control communication is necessary and the mobile station switches its receiving channel to a control channel only when it receives the switch signal. SOLUTION: A radio device 2 of a control office always monitors an active talking channel by a talking channel monitoring part 7. When the mobile stations 4 and 5 are talking to each other via a channel, a control part 6 receives the information on the active channel from the part 7 and transmits the control channel switch signal via the active channel. The stations 4 and 5 receive the control channel switch signal, switch their receiving channels to the control channel and receive the acquisition signal transmitted via the control channel. Thus, it's not required to periodically monitor the acquisition signal, and the simultaneous notification and the control communication can be received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disaster prevention radio system, and more particularly, to a system for reducing a disconnection between a control station and a mobile station and a plurality of mobile stations in a local disaster prevention radio system.

[0002]

2. Description of the Related Art FIG. 2 is a diagram showing an example of a conventional local disaster prevention radio system. In the figure, 1 is a control board, 2 is a control station radio device, and 3, 4, and 5 are mobile stations, respectively.
In this conventional regional disaster prevention radio system, mobile stations 3 to
Reference numeral 5 periodically switches from the communication channel S to the control channel CI in order to receive a broadcast message or control communication from the control station 2 even during a call. By switching to the control channel, a capture signal from the control station 2 is received,
Shift to broadcast or controlled communication. If not, continue the call. In the case of this conventional system, there is a drawback that the state in which the communication is interrupted is periodically generated because the control channel is once switched to the control channel. In particular, in the single-frequency simultaneous transmission / reception system operated in the duplex mode, because of continuous communication,
There was a drawback that this break was noticeable.

[0003]

In the above-described conventional system, the mobile station must receive the broadcast message and the control communication from the control station even during the call, so that the mobile station shifts from the call channel to the control channel during the call, We monitor acquisition signals regularly. Therefore, there is a disadvantage that the call is interrupted periodically for a predetermined time. An object of the present invention is to eliminate this drawback and eliminate interruptions in regular calls.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in order to achieve the above-mentioned object, a control station communicates with a mobile station during a call on a receiving channel of each station only when a broadcast message or a control communication occurs. A switching signal for switching from the channel to the control channel is transmitted, and the mobile station during a call can switch the receiving channel to the control channel only when the switching signal is received, and can subsequently receive the acquisition signal transmitted from the control station on the control channel. To do.

[0005] This eliminates the interruption of the conventional regular call and makes it easier to hear the call. As a result, it is not necessary for each mobile station to switch channels to monitor broadcast signals and control communication capture signals periodically during a call, so that calls can be made without interruption and good communication can be performed. Becomes

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. The same parts as those in FIG. 2 are denoted by the same reference numerals. Reference numeral 6 denotes a control station control unit, 7 denotes a traffic channel monitoring unit, and 8 denotes a control station radio. The mobile stations 4 and 5 are talking on the communication channel S1. FIG.
5 is a time chart showing one embodiment of the present invention. The operation of this embodiment is as follows. When the broadcast or control communication is performed from the control station 2, the mobile station 3 is in a standby state, so that the mobile station 3 receives a capture signal through the control channel and enters the broadcast and control communication. The control station 2 always monitors the currently used communication channel by the communication channel monitoring unit 7. As shown in FIG. 3, if the mobile stations 4 and 5 are talking on the communication channel S1, the control station control unit 6 receives the information on the communication channel used from the communication channel monitoring unit 7 and uses the information. The mobile stations 4 and 5 receive the control channel switching signal, switch the receiving channel to the control channel C, and receive the captured signal transmitted on the control channel. I do. Each mobile station starts broadcasting by receiving the acquisition signal. As a result,
There is no need to periodically monitor the captured signal, it is possible to receive a broadcast message or a controlled communication, and it is possible to eliminate interruption during a call, and the effect is enormous.

[0007]

According to the present invention, a mobile station can perform extremely smooth communication by eliminating a break in a periodic call that occurs during monitoring of a broadcast signal or a control communication capture signal during a call. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a conventional disaster prevention wireless system.

FIG. 3 is a flowchart showing the operation of one embodiment of the present invention.

[Explanation of symbols]

1: control table, 2: control station radio device, 3, 4, 5: mobile station, 6: control unit in control station radio device, 7: communication channel monitoring unit in control station radio device, 8: control station radio Radio inside the device.

Claims (1)

[Claims] 1. A disaster prevention wireless system in which a control station and a mobile station and a plurality of mobile stations are connected by a radio channel including a control channel and a communication channel, wherein the control station monitors a communication channel in the system. A communication channel monitoring unit for transmitting a switching signal for switching a receiving channel of each station during a call from a communication channel to a control channel only when performing broadcast or control communication from a control station. .