JPS5910626B2 - Blockage control method in mobile radio communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blocking control method for preventing radio wave interference in mobile communications between a large number of mobile stations and a plurality of fixed stations.

In mobile communications, it is necessary to prevent interference when mobile stations using the same frequency approach.

That is, as a certain mobile station moves, it is necessary to switch fixed stations and block adjacent fixed stations so that they do not use the same frequency. The number of fixed stations to be blocked is not limited to one, and if it is necessary to secure time until radio wave interference occurs, it is necessary to block the extra stations by the distance traveled within this time. In the case of general calls, it is normal to block the calls to ensure a 6 to 9 minute call, and in the Tokaido Shinkansen train radio system, the bases of several adjacent stations (for example, 4 zones in front of the train and 3 zones in the rear) are blocked. The station is blocked. The longer the call time is guaranteed, the longer the blockage will be, and the line usage efficiency will inevitably decrease. This improves line efficiency.

In any case, it is necessary to block several adjacent fixed stations due to the relationship between guaranteed call time and mobile station travel time. FIG. 1 is a block diagram for explaining a conventional system.
As shown in the figure, when mobile stations 101 and 102 are adjacent to each other in the direction of the arrows at the positions shown in the figure, mobile station 101 starts a call via fixed station 203, and mobile station 102 starts talking via fixed station 204. If you start a call, the mobile station 101.10
When two stations approach each other and enter the zone of the same fixed station, interference occurs.

Therefore, in order to prevent this, the mobile station 101
03, it is necessary to block the fixed stations 201 to 206 so that no new calls can be started within the zone of the fixed stations 201-206. In FIG. 1, from telephone 402 to switching device 40.
1 and the fixed stations 201 to 206 are blocked by the control line 301. When blockage is performed in this way, a situation occurs in which a mobile station located in a blockage zone is unable to open a line even if it tries to start a call. In particular, when the number of mobile stations is very large and the distance between mobile stations is narrow, such as on the JNR Shinkansen, and the amount of telephone calls is large, it is better to make the next call than the person who is actually talking. There are so many people waiting for a line to become available, and as soon as the line becomes free, many people activate it at the same time. But one out of many
Only a few people will actually be connected, and therefore some people will never get through no matter how many times they call. In other words, there are many cases in which even if a call is made after the line is displayed as being free, the call is almost never actually connected. The present invention aims to eliminate the above-mentioned drawbacks and to provide a method for configuring an economical system for preventing a large number of people from making calls at the same time the moment the line becomes free. FIG. 2 is a block diagram showing an overview of the present invention. In FIG. 2, the problem of the conventional method is solved by providing a time difference in the transmission of idle signal signals from blockage signal control circuits 501 to 510 when a call ends. This will be explained in detail using an example. Third
The figure is a block diagram showing an embodiment of the present invention, in which fixed stations 202 to 206 and blockage signal control circuit 5 in FIG.
02 to 506 are illustrated in detail, and in the figure, the fixed stations 202 to 206 include an antenna 601 and a transmitter 6.
02, a receiver 603, a transport device 604 for configuring a communication line, a blank line signal oscillator 605, and the like.

In a mobile radio system, the distance between fixed stations is usually 10 kilometers or more, and a wired or wireless carrier line is used as a communication line. Therefore, in this embodiment, a carrier line is also used as a communication line and a signal transmission line. did. Further, each of the blocking signal control circuits 502 to 506 is provided with a blank line signal sending control circuit 701, a contact 702 of a blank line signal time difference indicating relay 704 (FIG. 4), and a contact 703 of a call blocking indicating relay F. ing.
When a mobile station makes a call in the zone of the fixed station 203, radio waves coming from the antenna 601 are received by the receiver 603, transmitted to the carrier device 604, and then transmitted to the central station (not shown). At this time, the block instruction relay F of the central station (not shown) is activated, and its contact 703 stops sending out the idle line signal from the idle line signal oscillator 605 to the fixed stations 202 to 206 and closes them. Fixed station 202~
If there is no idle line signal from the 206 zone, it is no longer possible to make a call from a mobile station that is not talking. When the call ends, the blockage instruction relay F is restored and the blockage is released by the contact 703, but in this case, the blockage zones are not cleared at the same time, but are cleared at a predetermined time difference. FIG. 4 is a detailed explanatory diagram of an embodiment of the present invention,
705 is a timing circuit, and the others have the same meaning as explained in FIG.

In FIG. 4b, when the communication ends, the contact point 703 of the closure instruction relay F is restored, and the timing circuit 705 causes all of the time difference instruction relays 704 to operate according to the time difference as shown in FIG. 4a, for example. Restored and those contacts 70
2, the blockage is released with a time difference. The value of the time difference of the timing circuit 705 can be fixed for each zone, or can be freely varied. As described above, according to the present invention, in a mobile communication system, when communication that has continuously blocked multiple zones is terminated, it is possible to prevent calls from occurring frequently in close proximity and to reduce unnecessary connections. .

[Brief explanation of the drawing]

Figure 1 is a block diagram for explaining the conventional system.
FIG. 2 is a block diagram showing an overview of the invention, FIG. 3 is a block diagram showing an embodiment of the invention, and FIG. 4 is a detailed explanatory diagram of the embodiment of the invention. 101-103... Mobile station, 201-210.
... Fixed station, 301, 302 ... Control line, 401 ... Switching device, 402 ... Telephone, 501 to 510 ... Blockage signal control circuit,
601... Antenna, 602... Transmitter, 603... Receiver, 604... Transport device, 605... Blank line signal oscillator. , 701・
...Blank signal transmission control circuit, 703...
Contact point of call blockage instruction relay F, 704... idle line signal time difference instruction relay, 705... timing circuit.

Claims (1)

[Claims] 1. A mobile radio communication system between a central station (control station) and a large number of fixed stations (base stations) and mobile stations, wherein the central station and the mobile stations are connected via the fixed station. In a system in which the central station determines the blockage range of the fixed station and blocks the channels in use, it is sent when communication that has continuously blocked multiple base station zones ends. 1. A blockage control method for a mobile radio communication system, characterized in that the transmission of idle signal signals to mobile stations is controlled with a time difference to prevent calls from occurring in close proximity. 2 comprises a vacant line signal transmission control circuit for controlling a vacant line signal oscillator that oscillates the vacant line signal, a vacant line signal time difference indicating relay, and a timing circuit, and a predetermined time difference value from the timing circuit. The idle wire signal time difference indicating relay is operated with the predetermined time difference by a timing signal having a timing signal, and the idle wire signal sending control circuit is controlled with the predetermined time difference by the operation of the instruction relay. A blockage control method in the mobile radio communication system according to claim 1.