JPS5924573B2 - Wireless communication zone blockage control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an improvement of a communication zone blockage control method performed to prevent interference between mobile stations in a mobile communication system composed of a plurality of base stations and a plurality of mobile stations. It is related to.

In general, in such mobile communication systems, when different mobile stations approach each other, it is necessary to prevent mutual interference caused by the use of the same channel. The channel is prohibited from being used, and this is called blocking the communication zone of the base station. In addition, in general telephone communication, etc., the number of mobile stations is 6 to 9.
A predetermined number of adjacent communication zones are blocked, taking into consideration the moving speed of the mobile station, so that continuous calls can be made for a certain period of time. Taking the Tokaido Shinkansen train radio system as an example, the communication zones (hereinafter referred to as zones) are arranged as shown in Figure 1 as multiple communication zones formed by multiple base stations arranged in series. When the train 101 as a station is in zone E, the front six zones, zone F-, are blocked, and at the same time, the rear four zones, zones A-D, are blocked based on the moving direction indicated by the arrow.

Therefore, use of the same channel by other trains in these zones A- is prohibited.

Note that Z and L are other adjacent zones that are not blocked. FIG. 2 is a system configuration diagram showing the arrangement of the base stations AS-KS and the relationship with the control station MS that supervises them.
When the train 202 existing in zone E makes a call as a specific mobile station, a call signal is transmitted from the antenna ANT by the transmitter on the car ιL, which is received by the base station ES in zone E via the antenna ANT, and It reaches the control station MS via the multi-line ML, and is connected to the telephone T by the switch in the control station.
It is connected to any one of L1 to TLn to form a communication line. On the other hand, the control station MS sends a message to the base station ES, AS-DS, and FS-KS by receiving the call from the base station ES.
A blockage signal is sent via the multi-line ML, and the base station E
The same channel as the specific channel in the base stations AS-DS and FS-KS, including the specific channel used for configuring the radio line in S, is blocked, and other trains 201, 201,
203 is made impossible to use the same channel as the specific channel.

FIG. 3 is a block diagram showing details of the blocking Fbl control method, in which each base station AS-KS has an antenna multiplexer M
Pa-MPk, transmitter TXa-TXk, receiver RXa-
RXk, idle line signal generators SGa-SGk, and carrier terminal stations CEa-CEk as multiplexers, and the control station MS has signal controllers SCa to SCk corresponding to each idle line signal generator SGa-SGk. are provided, and each is connected by a multiplex line ML. In addition, each signal Fbl leg unit SCa-SCk is controlled by relay contacts E and es, and when relay contacts E and es are turned on, a blockage control signal is sent out and the empty line signal from the empty line signal generator SGa-SGk is stopped. It has become a must-see.

Therefore, as mentioned above, when a call from the train 202 arrives at the control station MS via the receiving system omitted in the diagram, relay contact e is first turned on, and this causes the empty line signal generator SGe to Because the signal stops, the transmitter TXe
Or, the transmission of the aerial signal via the antenna ANT disappears,
New calls cannot be made using the specific channel.

Next, since a different frequency is used as a calling signal depending on the traveling direction of the train 202, the discrimination circuit of the receiving system discriminates this and turns on the relay contact Es, thereby transmitting the signal to the empty line signal generator. SGa-SGd, SGf-
The idle signal from SGk stopped and base station AS-DS, F
Zones A-D and F-K of S-KS were also blocked, and train 20
It becomes impossible to make a call from the 1,203 side using the same channel as the specific channel.

However, in the above zone blockage control method, train 2
After blocking only zone E where 02 exists,
Other zones A-D, F- according to the traveling direction of the train 202
K is blocked, and it takes 2 to 3 seconds to determine the direction of travel.
Therefore, if calls from trains 201 and 203 are made on the same channel during this time, there is a risk that these calls will also be treated as legitimate calls, resulting in interference.

The present invention has the purpose of fundamentally eliminating the drawbacks of the conventional technology, and firstly, the specific channel used for the call in the zone where the call occurred, and the specific channels in the same number of front and rear zones adjacent to this zone. Immediately block the same channel, determine the train's direction of travel, and then release the blockage in the rear zone where blockage is not necessary, completely preventing calls from other trains using the same channel. This provides an extremely rational wireless communication zone blockage method.

The details of the present invention will be explained below with reference to FIG. 4 and subsequent figures showing embodiments.

FIG. 4 shows a zone blockage situation according to the present invention corresponding to FIG. Along with the specific channel of zone E where 202 exists, the same number of zones C adjacent to zone E
, D, F, G, and immediately block the same channel as the specific channel in zone C, D, F, G.
Even if there are other trains in the area, new calls from these trains on the same channel are blocked.

In addition, after determining the traveling direction of the train 202, as shown in FIG. Calls can be made using the same channel for trains existing in the same channel. Therefore, immediately after a call is made from the train 202, the same number of zones C, D, F, and G as required for continuous communication are blocked depending on the speed of the train 202, and the same number of zones C, D, F, and G are blocked before and after the same number of zones C, D, F, and G are blocked depending on the traveling speed of the train 202. However, after that, only zones C, D, and F, which originally require blocking, are blocked, thereby preventing interference from occurring and improving the operational efficiency of the line. FIG. 5 is a block diagram of each base station AS-KS and control station MS to realize the above-mentioned operation. In addition, a receiving system and a switch, etc., which are omitted in the diagram, are provided. is equipped with a circuit that selectively receives different calling signals depending on the moving direction of the train, that is, calling signals with different frequencies, and thereby determines whether the train is going up or down. Similarly to FIG. 3, a circuit for driving relay contact e is also provided. Therefore, when the train 202 in zone E makes a call using a specific channel and establishes a communication line with the control station MS via the base station ES, the base station CS-GS
Correspondingly, the relay contact e provided in each unit is turned on in the same way as shown in Fig. 3, and the transmission of idle signal from the base station CS-GS is stopped, and the specific channel of zone E and the same number of adjacent zones before and after this are turned on. Use of the same channel as the specific channel in C, D, F, and G is prohibited. In addition, the control station MS
, the switch turns on train 20 by turning on its crosspoint.
2 and the telephones TLl to TLn housed in the control station MS.
Since crosspoints are provided corresponding to each base station AS to KS and telephones TLl to TLn, it is possible to determine which base station is currently connected depending on the position of the crosspoint that is turned on. This shows whether the communication line is currently being configured.

Therefore, information corresponding to the position of the crosspoint that is turned on is given to the shift register SRAB, and busy information is stored in the stage STE corresponding to the base station ES. A memory is provided that a particular channel of the station ES is in use.

On the other hand, depending on whether the train 202 is going up or down, the shift register SRu
p or SRDN is selected, and shift register S
Information indicating the existence of the train 202 is stored in the stage STE corresponding to the base station ES using information similar to the information stored in the RAB, and if the train 202 is in the up direction, the shift register This information is stored in stage STE of SRup, which allows zone E
The fact that the train 202 in the up direction is present is stored.

On the other hand, the addressing signal As from the address counter that divides the clock pulse is given as a multi-bit code, and if the zone order indicated by this is n, then this is given as is to the X decoder DEC. Shift registers SRAB, SRU, SR
ON is applied via code converters CCV1 to CCV3, thereby shift registers SRAB, SRUP
, SRDN each stage STA-STK is addressed.

Then, the code converter CCVl determines the zone rank n! ! :
code converter CCV2 converts the zone ranking n to the zone ranking n+2, and the code converter CCV3 converts the zone ranking n to the zone ranking n-2. It's summery.

Further, when the decoder DEC receives the address designation signal As of the zone rank n, only the output X corresponding to the zone rank n among the outputs Qa to Qk is set to "H" (high level), and the others are set to "L" ( low level).

Therefore, when the addressing signal As specifies zone G as the zone order n, n-2 indicates zone I, n+2 indicates zone E, and stages STE of shift registers SRAB and SRUP are specified. Based on the information stored in this, the output Qn+2 of shift register SRAB and shift register SRu
, so that the output of the NAND gate G1 becomes "L".

On the other hand, n-2 indicates zone I, and since no information is stored in stage STI of shift registers SRAB and SRDN, output Qn-2 of shift register SRAB
2 and the output of shift register SRDN is "L1", and the output of NAND gate G2 maintains 1H.

The outputs of the NAND gates Gl and G2 are given to an input inversion type 0R gate G3, and the output of the 0R gate G3 changes to "H" in response to "L" from the NAND gate G1.
This is applied to input 2 of NAND gates Ga to Gk.

On the other hand, in the decoder DEC, only the output Qg is set to ``H1'' by the addressing signal As indicating the zone G, and this is applied to the input 1 of the NAND gate Gg, so the output of the same gate Gg is changed to 6L'', and the relay G1 operates to turn off relay contact g1, thereby unblocking zone G.

However, at this time, among the outputs Qa to Qk of the decoder DEC,
Other than Qg, it is L2, which is the NAND gate Ga-
Since it is given to input 1 of Gf, Gh-Gk, these outputs are H7, relays A1-Fl, Hl-K1 do not operate, and relay contacts a1-Fl, hl-kl maintain the on state. , among these, the blockage of zones C to F by the relay contacts e connected in series with Cl, dl, el, and fl, respectively, is not released.

Note that when the train 202 is in the down direction, information is stored in the stage STE of the shift register SRDN.
When the addressing signal As indicates a zone C, n-
2 specifies zone E, and the output QO-2 of shift register SRAB and shift register S
“H” is sent from RDN, and this time NAND gate G
The output of NAND gate G3 becomes 6L1, and as a result, the output of 0R gate G3 becomes 0H'', and the output Qc of decoder DEC becomes ``H'', so the output of NAND gate Gc changes to 6L''. , the relay contact C1 is turned off by the operation of the relay C1, and the blockage of the zone C is released.

In addition, the configuration shown in FIG. 5 can be arbitrarily selected according to conditions, and can be applied not only to railways but also to wireless communication services such as expressways, and can be freely modified in various ways.

As is clear from the above description, according to the present invention, the occurrence of interference due to calls made on the same channel in close proximity in time can be completely prevented, blockage of unnecessary zones is eliminated, and new calls can be made. Since sufficient service is provided for calls, significant benefits can be obtained in mobile communication systems for various applications.

[Brief explanation of drawings]

Fig. 1 is a zone arrangement diagram showing a conventional zone blockage situation, Fig. 2 is a system configuration diagram showing the arrangement of base stations and the relationship with a control station, and Fig. 3 is a block diagram showing a conventional zone blockage control method. FIG. 4 is a zone blockage situation diagram showing an embodiment of the present invention, and FIG. 5 is a block diagram of a base station and a control station that perform zone blockade in FIG. 4. AS-KS...Base station, MS...Control station, 201, 203...Train (mobile station), 20
2...Train (specific mobile station), A-K...
・Zone (communication zone), ANT...Antenna, j-MPk...Antenna multiplexer, T
Xa-TXk...Transmitter, RXa-RXk...
...Receiver, CEa-CEk...Carrier terminal station, SGa-SGk...Blank signal generator, SCa
-SCk...Signal controller, E, cl~g1...
...Relay, contact, A1~K1...Relay,
Gl, G2, Ga-Gk...NAND gate,
G3...0R gate RSRAB1SRUP7S
RDN...Shift register, DEC...
・Decoder, As... Address designation signal.

Claims (1)

[Claims] 1 Consisting of a plurality of wireless communication zones formed by a plurality of base stations arranged in series and controlled by a control station, and a plurality of mobile stations that move via each communication zone, When a radio link is configured between a station and the control station using any specific channel, the specific channel in the communication zone where the specific mobile station exists and the specific channel in another communication zone adjacent to the communication zone. In a mobile communication system that blocks the same channel as the specific mobile station, in response to a call from the specific mobile station, the specific channel of the communication zone in which the specific mobile station exists and the same number of communication zones adjacent to the communication zone are identified. After blocking the same channel as the channel, the moving direction of the specific mobile station is determined, and the blocking of a communication zone located at the rear of the adjacent communication zone that does not require the blocking is released. Featured wireless communication zone occlusion control method.