JPH09284164A - Channel selection system for local disaster-prevention radio system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surer channel by adding a channel control section to a conventional multi-channel radio equipment so as to reserve a prescribed frequency interval of operating channels or over thereby relieving load of an antenna installation condition and of in-case high frequency sneak path countermeasures. SOLUTION: A channel control section 6 always monitors channels used by all radio equipment sections 2. In the case of making communication by each radio section 2, it accesses the channel control section 6, which selects a channel to keep a prescribed frequency interval Δfmin from adjacent channel frequencies of adjacent radio equipment sections 2 or over, and the access radio equipment section 2 makes communication at the selected channel. Thus, a frequency interval Δf is increased for investigation of prevention of a high frequency effect, a load of in-case high frequency countermeasures and of an antenna installation condition are relieved and then a surer channel is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speech channel selection system in a regional disaster prevention wireless system.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing an example of a multi-line wireless device which has been conventionally used. In the figure, 1 is an antenna duplexer, 2 is a radio unit, 3 is a transmitting antenna, 4 is a receiving antenna, 5 is a remote control device, and a broken line portion of 7 is a housing for housing 1 and 2. In the conventional method, the communication channel selection of the local disaster prevention radio system is random selection, and the frequency Δf selected by the adjacent radio may be 25 kHz, which is the minimum value. To prevent the influence, it is necessary to study at Δf = 25 kHz. In order to prevent high frequency influence on other stations at Δf = 25kHz, it is necessary to install the transmitting and receiving antennas at a certain distance or more in order to obtain the coupling loss between the transmitting and receiving antennas, and to prevent the high frequency wave in the housing. It is necessary to obtain a sufficient degree of airtightness for each radio. Therefore, the installation condition of the antenna becomes very severe, and the housing becomes large and expensive.

[0003]

In the above-mentioned conventional method, the installation condition of the transmitting and receiving antennas is severe, and the coupling loss changes greatly depending on the condition of the installation place, and the work of adjusting the antenna position after installation is required. There are drawbacks. Also,
There is a drawback that the housing becomes large and it is difficult to secure the installation place. The present invention aims to alleviate these drawbacks and provide a more reliable communication line.

[0004]

In order to achieve the above-mentioned object, the present invention monitors and controls the channel selection of a plurality of radio equipment units so that adjacent frequency units are not selected. Is.

As a result, it is possible to set Δf at a certain value or more when a study for preventing high frequency influence on other stations is performed, and to reduce antenna installation conditions and measures for high frequency wraparound of the housing. Will be able to.

[0006]

1 is a block diagram showing an embodiment of a channel selection system of a regional disaster radio system according to the present invention, and the same parts as those in FIG. 2 are designated by the same symbols. Further, 6 is a channel control unit, and broken line portions of 7 are 1, 2,
6 is a housing for housing 6. The operation of the channel selection system according to the present invention thus configured is as follows.

The channel controller 6 constantly monitors the channels using all the radio units 2. When each radio unit 2 communicates, it accesses the channel control unit 6, and the channel control unit 6 selects a channel so as to keep a frequency interval Δf _min above a certain level with the adjacent radio unit 2 to perform radio communication. The machine unit 2 communicates on that channel.

With the above operation, Δf when considering the influence of high frequency becomes large, and it becomes possible to provide a more reliable line by reducing high frequency measures in the housing and antenna installation conditions.

[0009]

As described above, according to the present invention, in a multi-line wireless device, in order to prevent a high frequency effect, the installation condition of the transmitting and receiving antennas becomes severe, and it is necessary to adjust the antenna position after installation. In addition, the disadvantage that the housing becomes large and it is difficult to secure the installation place can be alleviated, and a reliable line can be provided.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an example of a conventional method.

[Explanation of symbols]

1: Antenna duplexer, 2: Radio unit, 3: Transmission antenna,
4: reception antenna, 5: remote control device, 6: channel control unit, 7: housing.

Claims (1)

[Claims] 1. An antenna duplexer and a plurality of radio units in a local disaster prevention radio system are housed in one housing, and a plurality of lines are connected to the housing by one transmitting antenna and one receiving antenna, and remote control is performed. A multi-line wireless device that is operated simultaneously by the devices is characterized by having a channel control unit that monitors and controls the communication channel selection of each wireless communication unit and prevents adjacent wireless communication units from selecting a close frequency. Channel selection method.