JPH01305629A - Repeating system for simplex communication system - Google Patents

Abstract

PURPOSE:To execute satisfactory communication even in an area, where the intensity of radio waves from respective repeating stations is almost equal, by providing a selection control means to selectively execute repeating operation by the plural repeating stations on the repeating station. CONSTITUTION:An opening and closing switch 18 is interposed in a connecting line between a receiver 8 and a transmitter 9 of repeating stations 2 and 3 and an opening and closing switch 19 is interposed in a connecting line between a receiver 10 and a transmitter 11 of repeating stations 2 and 3. Selecting and calling devices 16 and 17 are operated with receiving selecting and calling signals (selection control signals) to be transmitted from a master station radio 20 and a moving station radio 21 respectively and the opening and closing switches 18 and 19, which are normally in a closing condition, are opened and driven. Then, only one desired repeating station is controlled so as to execute transmitting operation. Thus, even when the moving station radio exists in an overlap part 22 of a service area, a communication trouble due to the generation of a beat is canceled since only one repeating station is selected and utilized for repetition.

Description

Detailed Description of the Invention [Industrial Field of Application] This invention relates to simplex communication having a plurality of radio stations (master station radio, mobile station radio) that transmit radio waves of the same frequency within the same communication system. This relates to the relay method in the system.

[Prior Art] Conventionally, in mobile radio lines, in order to cover a wide area, a system has been adopted in which two or more radio stations for mobile stations are provided to cover a wide area. In this case, there are methods in which multiple relay stations are installed in parallel, methods in which multiple relay stations are installed in series, and methods in which a master station and a relay station are equipped with a radio that directly communicates with the mobile station radio. etc.

In the following, a relay method of a conventional simplex communication system will be described in the case where two relay stations are installed in parallel.

FIG. 4 is a system configuration diagram for explaining the relay method of a conventional simplex communication system. In the figure, 1 is a master station radio, 2 and 3 are relay stations installed in parallel, and 4 is a relay station. 2
5 is the service area of relay station 3,
These service areas 4 and 5 partially overlap each other.

Further, 6 is a mobile station radio located within the service area 4 of the relay station 2, and 7 is a mobile station radio located within the overlapping portion of the service areas 4 and 5.

8 is a receiver (Rx) that receives radio waves of frequency F on the relay line with the master station radio 1; 9 is a receiver (Rx) that receives radio waves at the frequency F of the relay line with the master station radio 1; 10 is a receiver (Rx) that receives radio waves of frequency F from mobile station radio 6 or 7, 11 is received by this receiver 1-O. The radio waves are of frequency F. A transmitter (Tx) that transmits to the master station radio 1 instead of A set of transceivers is configured.

Furthermore, 12 is an antenna 14 and a receiver 8 or a transmitter 1.
An antenna selector switch 13 is used to switch between the antenna 15 and either the transmitter 9 or the receiver 1.
These switches 12 and 13 are normally used to switch and connect to either one of the receivers 8 and 8. ] O side, and if there is human power on one of the receivers 8 or 10, turn the antenna switch 2 or 13 on the output side of the transmitter 9 or 11 so that it is connected to the transmitter 9 or 1] side. It has become.

Each relay station 2, 3 has the above-mentioned receiver 8, 10° transmitter 9.
, 11. Changeover switch 1.2.13 and antenna 14.
It consists of 15.

Next, the operation will be explained. Now, when the master station radio 1 and the mobile station radios 6 and 7 make a call, the frequency F from the master station radio 1 is used. The radio wave enters the antenna of relay station 2]4,
The signal is transmitted from the antenna 15 through the receiver 8 and the transmitter 9 to the mobile station radios 6 and 7 as a radio wave of frequency F□. At the same time, the radio wave from the master station radio 1 is also received by the antenna [-4] of the relay station 3, and is transmitted to the mobile station radio 7 through the same route as described above. At this time, since the mobile station radio 6 is within the service area 4 of the relay station 2, it receives only the radio waves from the relay station 2, while the mobile station radio 7 is located in the overlap area between the service areas 4 and 5. Since they are located within the same area, they will receive radio waves from relay stations 2 and 3 at the same time.

Conversely, when a radio wave is transmitted from the mobile station radio 6 to the master station radio 1, the radio wave of frequency F□ from the mobile station radio 6 is received by the antenna 15 of the relay station 2, and the radio wave is transmitted to the receiver 10. and frequency F from the antenna 1-4 to the master station radio 1 through the transmitter 11. and received by the master station radio device 1. On the other hand, when transmitting radio waves from the mobile station radio 7 to the master station radio 1, the mobile station radio 7 is within the overlap between service areas 4 and 5, so the relay station 2 The radio waves passing through the relay station 3 and the radio waves passing through the relay station 3 are simultaneously received by the master station radio 1.

[Problems to be Solved by the Invention] Since the relay method of the conventional simplex communication system is performed as described above, when there is a mobile station radio in the overlapping area between service areas 4 and 5, both relay stations 2, There is no problem if the difference in the strength of the radio waves from 3 is large, but if the strengths of 1 are almost equal, there is a slight frequency difference between the radio waves emitted by rain relay stations 2 and 3, so a beat will occur in the receiver output. Reception may become unclear or unreceivable.

Furthermore, when transmitting from the mobile station radio 7 to the master station receiver 1, a similar phenomenon occurs in the master station receiver 1-.

This invention was made to solve the above-mentioned problems, and it is a simplex communication system that allows good communication even in areas where the strength of the radio waves from each relay station is approximately equal when multiple relay stations are installed. The purpose is to obtain a relay method for communication systems.

[Means for Solving the Problems] A relay system for a simplex communication system according to the present invention includes a relay station equipped with a selection control means that allows a plurality of relay stations to selectively perform relay operations, and a master station radio or When transmitting radio waves from the mobile station radio, a selection control signal is also transmitted to operate the selection control means to select only one desired relay station from a plurality of relay stations. It is something to do.

[Function] In the relay method of the simplex communication system according to the present invention, when transmitting radio waves from the master station radio device or the mobile station radio device, a selection control signal for selecting a desired relay station to be used is also sent. The selection control means that has received the transmitted selection control signal controls only one of the desired relay stations to perform a transmission operation. As a result, even if a mobile station radio is present in the overlapping part (beat generation area) of the service areas of multiple relay stations, only one relay station is selected and used for relay, so communication due to the occurrence of beats is possible. Obstacles are resolved.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
The figure is a system configuration diagram for explaining a relay method of a simplex communication system according to an embodiment of the present invention. Omitted.

In FIG. 1, 16 is a selective call bag W (selection control means) attached to the receiver 8 of the relay stations 2 and 3; 17 is the relay station 2,
3, a selective calling device (selection control means) attached to the receiver 10; 18, an open/close switch interposed in the connection line between the receiver 8 and the transmitter 9 of the relay stations 2 and 3; 19, the relay station 2; 3, an opening/closing switch interposed in the connection line between the receiver 1o and the transmitter 11; 20, a master station radio having a selective calling function; 21, a mobile station radio having a selective calling function; 22, a beat zone (2); This is the overlapping part of the service areas of the two relay stations 2 and 3).

The selective calling devices 16 and 17 are connected to the master station radios 20 and 20, respectively. It operates in response to a selective call signal (selective control signal) transmitted together with the radio waves transmitted from the mobile station radio 21, and based on the selective call signal, opens/closes the switch 18 and 19, which are normally closed. It is driven in an open manner.

Next, a relay method in the simplex communication system configured as described above will be explained.

When attempting to make a call between the base station radio 20 and the mobile station radio 21 located in the beat zone 22, for example, the base station radio 20 sends a selective call signal to the relay station 2 at frequency F. The case of transmitting together with the radio waves = 7- will be explained first. At this time, the radio waves are transmitted to relay station 2,
However, since the selective calling signal of the relay station 2 is included, the selective calling signal of the relay station 2 is received by the selective calling device 16 attached to the receiver 8 at the relay station 2. Detected and received.

As a result, the selective calling device 16 operates to open the on/off switches 18, 19 in the relay station 2 for a certain period of time, thereby disconnecting the receivers 8, 10 and the transmitter 9-11. Therefore, radio waves are no longer emitted from the transmitters 9 and 11 of the relay station 2.

On the other hand, relay station 3 also receives radio waves from master station radio 20, but since the selective calling signal of relay station 3 is not included,
The selective calling device 16 does not detect or receive the selective calling signal, and the open/close switches 18 and 19 in the relay station 3 remain closed.

As a result, communication between the master station radio 20 and the mobile station radio 21 is conducted through the relay station 3.

In this state, only the radio waves from relay station 3 of relay stations 2 and 3 will be transmitted to mobile station radio 21 at frequency F1, so mobile station radio 21 will not be able to beat the beat as before. This will not occur and communication failures can be resolved.

Also, when the mobile station radio 21 transmits a selective calling signal for the relay station 2 or 3 along with radio waves of the frequency F1, the relay is performed in substantially the same manner as in the above case. However, in this case, the selective calling device 17 attached to the receiver 10 of the relay station 2 or 3 operates, and the on/off switch 1
8.19 opening drive is performed.

Here, the open/close switches 18 and 19 are configured so that once they are opened, they automatically return to the closed state after a certain period of time. This is because there may be cases where relay processing of other communications is urgently required and immediate recovery is required. For this reason, the selective call signal also includes a switch return signal, and by sending this signal, the open/close switch 18.1
It is desirable to add a function to the selective calling device 16, 17 to return the device 9 to the closed state so that it can be returned to the closed state at any time.

In the above embodiment, the case where the selective calling devices 16 and 17 are attached to the receivers 8 and 10 in all (two) relay stations 2 and 3 has been described. When there are two relay stations, as shown in FIG. 2, one relay station 3 is not equipped with a selective calling device 16, 17, and only the other relay station 2 is equipped with a selective calling device 16, 17 for simple communication. A communication system may also be configured. In this case, when the mobile station radio 21 is in the beat zone 22, by transmitting a selective calling signal for the relay station 2 and using only the relay station 3,
The same effects as in the above embodiment are achieved.

Further, in the above embodiment, in the relay station 2 or 3 that receives the selective call signal, the on/off switch 18.19 is driven open to prevent transmission, but conversely, the on/off switch 18.19 is always open. Even if the relay station 2 or 3 which receives the selective call signal closes the open/close switches 18 and 19 to perform transmission, the same effect as in the above embodiment can be obtained.

Furthermore, in the embodiment described in -1- above, the case where there are two relay stations has been explained, but the system of the present invention is not limited to this, and can be applied in the case where there are three or more relay stations. A similar effect can be obtained.

Further, when the relay line with the master station radio 20 is a multiplex radio line, the same effects as in the above embodiment can be obtained by configuring the relay station as shown in FIG. In FIG. 3, reference numeral 23 denotes a multicarrier terminal device for communicating with the master station radio 20. In FIG.

[Effects of the Invention] As described above, according to the present invention, a relay station is equipped with a selection control means that allows a plurality of relay stations to selectively perform relay operations, and a base station radio or mobile station radio When transmitting radio waves from the mobile station radio, a selection control signal is also transmitted to operate the selection control means to select only one desired relay station to be used for relay, so that the mobile station radio can If the relay station is in the I-zone, the generation of beats in the receiver output can be reliably prevented by selecting the desired relay station and remotely controlling the start of transmission using a selection control signal from the master station radio or mobile station radio. This has the effect of preventing the occurrence of communication failures.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram for explaining a relay method of a simplex communication system according to an embodiment of the present invention, and FIG. 2 is a system configuration diagram for explaining another embodiment of the invention.
Figure 3 is a configuration diagram of a relay station when the relay line between it and the master station radio is a multiplexed radio line, and Figure 4 is a system configuration diagram for explaining the relay method of a conventional simplex communication system. be. In the figure, 2, 3--relay station, 16.17--selective calling device (selection control means), 18.19--opening/closing switch, 20--master station radio, 21--mobile station radio. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A plurality of relays equipped with a master station radio and a mobile station radio, and relaying radio waves of the same frequency from the master station radio to the mobile station radio or from the mobile station radio to the master station radio. A relay system for a simplex communication system equipped with a plurality of relay stations, wherein the relay station is equipped with a selection control means that allows the plurality of relay stations to selectively perform relay operations, When transmitting radio waves from the machine, a selection control signal is simultaneously transmitted to operate the selection control means, and only one desired relay station to be used for relaying is selected from the plurality of relay stations. Relay method of simplex communication system.