JP4909879B2 - Mobile voice communication system and method - Google Patents

Description

  The present invention relates to a mobile voice communication system and method for performing voice communication between a mobile body moving linearly on a track, for example, a railway vehicle such as a Shinkansen and a fixed communication network.

As a conventional technique, in a control station that has jurisdiction over a plurality of radio base stations, the voice channel being used is reserved in advance (blocked) at the next radio base station in the moving direction of the moving body, and the moving destination of the moving body When the base station detects the entry of a mobile unit, it switches the line reserved in advance (reserved voice channel) and continues the call using the reserved voice channel to avoid line disconnection. Patent Document 1 proposes a technique for securing and preventing call interference.
However, when the mobile body moves between base stations, the time for the control station to switch the line between the base station before the movement to the line between the base station and the destination base station is very small. There was a problem that the call was interrupted for a moment for a caller using the phone.
In response to such a problem, the applicant first divides the area of the moving body in the traveling direction into a plurality of zones, and the voice channels of the plurality of zones in the traveling direction from the zone where the moving body exists and one zone in the opposite direction. Proposed a mobile communication method in which the same voice as in a zone in which a mobile object is present in one zone in the forward direction is flown in advance. In other words, in this mobile method, when the train moves between base stations, the control station outputs a voice to the front base station zone in advance, so that the train immediately receives a voice from the ground when the train is handed over. It was possible to receive a signal.

Japanese Patent Laid-Open No. 3-185938

However, when there are opposing mobile bodies (trains) that are talking on the same channel, if the control station outputs voice signals to the front base station zones of both trains, interference may occur.
The present invention has been made in view of the above problems, and provides a mobile communication system and method capable of preventing interference.

  In the present invention, the control station manages the existing zones of the opposing trains, and when the interference occurs, the front voice signal for the train causing the interference to the other party is stopped.

  In a busy train, it is possible to prevent voice signal interference due to the voice pre-blow function and to shorten the time of interruption of the voice signal at the time of handover. Even when an oncoming train talking on the same channel approaches, it is possible to stop the voice pre-blow function on one side and continue the other voice pre-blow function to shorten the interruption time of the voice signal at the time of train handover as much as possible. It becomes possible.

  Embodiments of the present invention will be described below.

FIG. 1 is a block diagram showing a mobile communication system to which the present invention is applied. In FIG. 1, reference numeral 1 denotes a mobile body such as a train, 2 denotes a mobile body 1 that communicates with a transmission line 3 including a wireless line, and a base station 4 that exists in its own radio wave zone. A control station telephone exchange that exchanges and connects a certain mobile station 11 with the railway company telephone network 5 and the public telephone network 6 and supervises a plurality of base stations, and 7 is a telephone set that subscribes to the railway company telephone network 5. , 8 are telephones subscribing to the public telephone network. Reference numeral 9 denotes a tracking line for transmitting / receiving control information necessary for handing over between the control stations under the control of a mobile unit and a voice signal during the call. The mobile station 11 accommodates the business telephone set 12 and the public telephone set 13 and includes a processor 111 and a memory 112, and software control is performed by the processor 111 based on a program stored in the memory 112. The control station telephone switch 2 has a processor 21 and a memory 22 and is controlled by software.
FIG. 2 shows that in the conventional method (Japanese Patent Laid-Open No. 3-185938), the mobile 1 that is in communication with the terrestrial telephone network exists in the base station A zone within the control station A jurisdiction, and then remains in the call state within the control station jurisdiction. It is a sequence which shows the call continuation procedure at the time of moving to the base station B zone. The procedure will be described in detail below. In the sequence of FIG. 2, the mobile station and the terrestrial telephone network are omitted, but the same signal is transmitted and received between the terrestrial telephone network and the control station, and the mobile station 11, the base station A, and the base station It is assumed that the same signal also flows in the audio signal with the station B (hereinafter, the same applies to FIGS. 3, 4 and 5).
That is, the base station relays control signals and audio signals between the mobile station 11 and the control station. As for the control related to the control station, the control signal and audio signal from the mobile station 2 are stored in the memory and controlled by the processor. Similarly, in the mobile station 11, the control signal and the audio signal from the control station are stored in the memory and controlled by the processor.
First, when the control station accepts a call between the mobile unit 1 and the terrestrial telephone network (S6 in FIG. 2), the control channel ch is used to send a total block signal S7 to the base station A, and similarly to the base station B. A total block signal S8 is sent out, and the voice channel ch used in the call is disabled in other mobile units. After that, the mobile station 11 and the control station in the moving body transmit / receive control information before a call (S9 in FIG. 2), and shift to a call state.
After the call starts, the base station A uses the control channel ch while receiving the voice signal S10 from the mobile unit 1, and sends a busy signal S11 indicating that the mobile unit 1 is using the voice channel ch. Send to the control station. At this time, the base station B zone is a completely blocked zone, and the busy signal S12 from the mobile unit 1 is sent to the base station B zone in consideration of the movement of the mobile unit 1 in the call to the base station B zone. It is constantly monitored.
Thereafter, when the mobile unit 1 moves from the base station A zone to the base station B zone (S3 in FIG. 2), the control station receives the voice signal and the busy signal S12 from the base station B. Assuming that the station has moved to the station B zone, the control station switches the line to the base station B (S13 in FIG. 2). At the same time when the line is switched, the audio signal 14 is sent from the control station to the base station B, and the audio signal reaches the mobile 1. However, the mobile station 11 in the mobile 1 recognizes that the control station has moved to the base station B after moving to the base station B zone, switches the line, and receives the audio signal S14 at the mobile station 11. The telephone set in the moving body 1 is heard as silence (S15 in FIG. 2).
FIG. 3 is a sequence diagram for realizing the present invention when a mobile unit in a call moves between base stations within the jurisdiction of the same control station. Details will be described with reference to FIG.
First, when the control station accepts a call between the mobile 1 and the terrestrial telephone network (S6 in FIG. 3), the control station ch uses the control channel ch to send a total block signal S7 corresponding to the voice channel ch used for the base station A, Similarly, to the base station B, a total block signal S8 corresponding to the voice channel ch used for the call is transmitted. At this time, the control station connects the line to the base station B and prepares to transmit the audio signal to be transmitted to the base station A to the base station B (S8 ′ in FIG. 3).
Thereafter, the control information before the call is transmitted and received between the mobile station 11 and the control station in the mobile unit 1 (S9 in FIG. 3), and the call is started. Next, the control station receives the audio signal from the ground network and sends the audio signal to the base station A and the base station B (S10, 10 'in FIG. 3).
Further, the base station A sends out the voice signal from the mobile station 11 to the control station and sends out the busy signal (S11 in FIG. 3). Thereafter, since the mobile unit 1 moves from the base station A zone to the base station B zone, the mobile station 11 can receive a voice signal from the terrestrial telephone network in the voice channel ch. A signal can be received (S16 in FIG. 3).
Further, since the base station B receives the voice signal from the mobile station 11 and simultaneously transmits a busy signal to the control station, the control station recognizes that the mobile 1 has moved to the base station B (S12 in FIG. 3). ).
FIG. 4 is a sequence showing a voice communication continuation procedure when a mobile unit in communication with the terrestrial telephone network moves between base stations under control of different control stations in the conventional system, and will be described in detail.
First, when the control station A accepts a call between the mobile 1 and the terrestrial telephone network (S6 in FIG. 4), it uses the control channel ch to send a total block signal S7 to the base station A and a block instruction signal to the control station B. (Total blockage) S8 is sent out. The control station B that has received the block instruction signal S8 transmits a total block signal S8 ′ to the base station B in order to disable the use of the voice channel ch.
Thereafter, pre-call control between the control station and the mobile station 11 is performed via the base station A, and the call state is changed (S9 in FIG. 4). Simultaneously with the transition to the call state, the control station A sends the voice signal S10 from the terrestrial telephone network to the base station A, and the base station A sends the voice signal and the busy signal from the mobile station 11 to the control station A.
Next, when the mobile unit 1 moves to the base station B zone under the control of the control station B, the control station B receives a voice signal from the base station B on the voice channel ch, and therefore transmits a busy signal S12 to the control station B. . Receiving the busy signal, the control station B sends a tracking instruction signal S17 to the control station A using a tracking line in order to perform voice tracking between the control stations. When the control station A receives the tracking instruction signal S17, it is considered that the mobile 1 has moved to the control station B jurisdiction zone, and in order to make a voice call with the control station B, a tracking line is connected (S19 in FIG. 4) and tracking is performed. A confirmation signal S20 is sent to the control station B. Upon receiving the tracking confirmation signal S20, the control station B determines that the voice line with the control station A is ready, and sends the voice signal S22 from the base station B to the control station A. The voice call is continued as described above.
However, in this sequence, in a call using the telephone in the mobile 1, the control station B receives the busy signal from the base station B, instructs the control station A to track, and the line between the control stations is connected. Until the audio signal S21 from the station A is received, it is heard as silence (S23).
FIG. 5 is a sequence showing a procedure to which the present invention is applied when a moving object in communication with the terrestrial telephone network moves between base stations under different control stations, which will be described in detail.
First, when the control station A accepts a call between the mobile 1 and the terrestrial telephone network (S6 in FIG. 5), it uses the control channel ch to send a total block signal S7 to the base station A and a block instruction signal to the control station B. (Full blockage) S8 is sent, a tracking line to the control station B is connected, and preparations are made to send a voice signal to the control station B using the voice channel ch (S24 in FIG. 5).
Next, the control station B that has received the block instruction signal S8 transmits a full block signal S8 ′ to the base station B and connects the line to the base station B so as to be able to play an audio signal (FIG. 5). S18).
Thereafter, the control station A that has transmitted the block instruction signal S8 performs control before the call with the mobile station 11 through the base station A (S24 in FIG. 5), and transitions to a call state. When a transition is made to the call state, the control station A sends an audio signal S10 to the base station A and sends an audio signal to the tracking line to the already connected control station B. The control station B that has received the audio signal S10 from the control station A sends the audio signal S10 toward the base station B.
In addition, in the base station A that relays the voice signal S11 from the mobile station 11, the busy signal S11 is sent to the control station A, and the mobile unit 1 and the terrestrial telephone network communicate. Thereafter, when the mobile unit 1 moves from the base station A zone under the control of the control station A to the base station B zone under the control of the control station B (FIG. 5), the base station B receives the audio signal S12 from the mobile station 11.
The base station B that has received the voice signal S12 sends a busy signal to the control station B together with the voice signal. Thereafter, the control station B that has received the audio signal S12 relays the audio signal to the control station A (S24 in FIG. 5), and continues the call between the mobile unit 1 and the terrestrial telephone network.

In the first embodiment, a mobile voice communication method has been described in the case where a train that is talking is handed over between base stations within the jurisdiction of a certain control station, and when different train stations are handed over.
In the second embodiment, a mobile voice communication method will be described in the case where a train that is talking on the same channel as the train approaches the train that is talking.
First, the above-described interference will be described with reference to FIGS. 6 and 7, and the interference prevention will be described with reference to FIGS. Here, the processing in FIGS. 6, 7, 8, and 9 is assumed to be realized by a processor in the control station.
FIG. 6 is a diagram illustrating that the train A (1 in FIG. 6) and the train B (2 in FIG. 6) that are talking on the same channel are traveling in opposite directions. Z3 to Z6 in FIG. 6 are a base station zone where train A is present (3 in FIG. 6), a voice front blowing zone for train A (Z4 in FIG. 6), and a base station zone where train B is present (Z6 in FIG. 6). ) And a state block diagram showing a voice front blowing zone for the train B. At this time, the voice front blowing zones of the train A and the train B are pre-occlusion zones of the respective trains.
In the state shown in FIG. 6, if the opposite trains A and B are talking on the same channel, trains A and B send voice signals from the ground to the vehicle in advance in the traveling direction base station zone. When A and B are handed over, voice can be received immediately. However, when each of them is talking on the same channel, there is a risk of interference due to the approach of trains A and B. FIG. 7 is a diagram illustrating a state where the train B (2 in FIG. 7) is handed over in the state of FIG. At this time, according to the conventional technique, train B has entered the opponent's all-occluded zone, so if the forced disconnect mode is set, the train B will be disconnected within a certain time. This is done to prevent interference and to restrict trains that talk in the same zone and channel.
In the state of FIG. 7, for example, when the voice front blowing for both trains is performed to the front zone (4 of FIG. 7) of the train A (1 of FIG. 7) and the train B (2 of FIG. 7), the train A at this time Is not controlled by the control station at the position in the zone where the line is currently in communication (the detailed position of the train is unknown), and if train A is located near the boundary with the forward zone (Z4 in FIG. 7) If the train A is handed over immediately after the handover of B, the front blowing voice of the train B is received, resulting in interference.
In the present invention, in order to prevent such a problem, when the state shown in FIG. 7 is reached, the control station stops the voice pre-blowing for one train.
FIG. 8 schematically shows a solution to the above problem. In the state of FIG. 8, the train B (2 in FIG. 8) is in a forced disconnection mode and is disconnected within a certain time. This time is shorter than the time required for the train to pass through all base station zones.
Therefore, the train B is disconnected while it is in the handover destination base station zone (Z5 in FIG. 8) and enters the voice front blowing zone of the train A as long as the train A (1 in FIG. 8) is talking. There is no. From this feature, the present invention prevents the opposite train from interfering by stopping the voice pre-blow function when the train that has entered (handed over) first into the all blocked zone of the opponent enters the forced disconnect mode. (Z4 in FIG. 8).
When the train A (1 in FIG. 9) ends the call in the state of FIG. 8, the train B (2 in FIG. 9) is released from the forced disconnection mode. By restarting the voice pre-blow function of the train B at this timing, the voice pre-blow function is applied even if the train B is subsequently handed over.
Next, FIG. 10 shows a sequence diagram for realizing the prior art, and the processing will be described. This sequence is realized by the processor of the control station.
When the control station receives a call from a certain train (S101 in FIG. 10), it prepares a channel to be used for a call and reserves a call channel for the front base station zone of the channel (blocking) (FIG. 10). 10 S102). Next, a voice signal from the ground is sent to the front base station zone when the call starts (A103 in FIG. 10).
Thereafter, when the call is finished (S104 in FIG. 10), call disconnection processing is performed (S109 in FIG. 10). Here, the disconnection process releases the voice channel used for the call with the mobile station and releases the blockage associated with the call. Next, when a train that is talking moves and is handed over between base stations (S105 in FIG. 10), an audio signal is transmitted to the base station zone that is the destination and the front base station zone that is the destination (FIG. 10). S106).
Further, at the time of handover, when the call channel is already blocked by a train that is opposite to the base station zone one zone before the destination base station zone, a forced disconnection mode is set in which the call is disconnected after a call for a certain time (see FIG. 10). S107). Thereafter, when the opposite train completes the call within a certain time, the forced disconnection mode is canceled and the call state is restored.
In the prior art, since the voice signal is transmitted to the front base station zone when the forced disconnection mode is set, if the oncoming train is handed over to the zone in this state, interference occurs.
Processing for realizing a solution (the present invention) to such a problem will be described with reference to FIG. FIG. 11 is a sequence diagram for realizing the present invention, and the processing will be described below. This sequence is realized by the processor of the control station.
When the control station accepts a call from a certain train (S101 in FIG. 11), it prepares a channel to be used for a call and reserves a call channel for the front base station zone of the channel (blocking) (FIG. 11). 11 S102). Next, a voice signal from the ground is sent to the front base station zone when the call starts (S103 in FIG. 11). Thereafter, when the call is finished (S104 in FIG. 11), call disconnection processing is performed (S109 in FIG. 11).
Next, when a train that is talking moves and is handed over between base stations (S105 in FIG. 11), an audio signal is transmitted to the base station zone that is the destination and the front base station zone that is the destination (FIG. 11). S106). Further, in the case of a handover, when a call channel is already blocked by a train facing the front base station zone of the destination base station zone, a forced disconnect mode is set in which the call is disconnected after a certain time (S107 in FIG. 11). In the control station, interference is not generated even if the oncoming train is handed over by setting the forced disconnection mode of the train and stopping the transmission of the audio signal to the front base station zone of the entry destination (S108 in FIG. 11). . Further, when the opposite train completes the call within a certain time (S109 in FIG. 11), the forced disconnection mode is canceled, the call state is restored, and the transmission of the audio signal to the front base station zone is resumed. (S111 in FIG. 11).

  The present invention relates to a mobile communication method for performing call connection communication with a mobile body that moves linearly on an orbit, and in particular, when a mobile body in a call moves between base stations, it is transmitted from a ground telephone network. The present invention relates to a mobile communication control system for receiving a received audio signal without interruption on the mobile side.

1 is a block diagram of a mobile communication system showing an embodiment of the present invention. Sequence diagram showing a method for continuing a voice call when a mobile unit in a call moves between base stations within the same control station in the conventional system The sequence diagram which shows the continuation method of the voice call when the mobile body in a call moves between base stations in the same control station jurisdiction in the present invention Sequence diagram showing a voice call continuation method when a mobile unit in a call moves between base stations under different control stations in the conventional system The sequence diagram which shows the voice call continuation method at the time of moving between the base stations of the control station jurisdiction from which the mobile body in a call differs in this invention State diagram showing opposite trains talking on the same channel State diagram when train B is handed over State diagram showing the present invention State diagram showing the present invention Sequence diagram for realizing the conventional method Sequence diagram for realizing the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mobile body, 11 ... Mobile station, 111 ... Processor, 112 ... Memory, 12 ... Business telephone, 13 ... Public telephone, 2 ... Control station telephone switch, 21 ... Processor , 22 ... Memory, 3 ... Transmission path, 4 ... Base station, 5 ... Railway company telephone network, 6 ... Public telephone network, 7 ... Railway company telephone, 8, ...・ General telephone, 9 ... Tracking line.

Claims (4)

Between the mobile and the fixed network for high-speed long-distance lines to move in a mobile communication system for performing voice communication using the same channel from the start to the end of the call, the in order to establish communication for a predetermined time transition area of the moving body is divided into a plurality of zones, wherein the existing zone than the traveling direction of the moving body (front) a few zones and the opposite direction first zone (rear zone) reserved closed during call connection, further forward zone 1 wherein by flowing the same voice and the base station zone existing mobile beforehand, the moving body is allowed to continue voice without interruption voice from the ground even when moving forward zone to the mobile direction,
When the mobile unit is in a call and an opposing mobile unit that makes a call on the same channel approaches, the mobile unit that entered the pre-blocking zone of the other party's call channel first is within a certain time (within the base station transit time) The mobile voice communication method of making the disconnection of the voice to be forcibly disconnected and stopping the front blowing of the voice signal so that when one of the mobile bodies is handed over, the voice is interrupted minutely. In claim 1, the moving body has entered the previously mating of the pre occlusion zone is forced disconnection target, if the opposing moving bodies has terminated the call, forward the base is released with the cutting target of the opposing moving bodies A mobile voice communication method for minimizing voice interruption when the mobile body is handed over by resuming transmission of a voice signal to a station. In a mobile unit including a train that moves linearly at high speed over a long distance, a mobile station that accommodates public telephone terminals and business telephone terminals, a base station that accommodates signals from the mobile station, and the mobile station and public telephone network A mobile communication system comprising a control station telephone exchange device for exchanging and connecting to a telephone company telephone network, and performing voice communication using the same channel from the start to the end of a call,
The control station telephone switching device divides the mobile station's transition area into a plurality of zones in order to secure a call for a certain period of time. When the mobile station moves in the traveling direction by preliminarily blocking the zone and further playing the same voice as the base station in which the mobile station exists in the base station in the traveling direction 1 zone in advance. Continue the voice without interruption from the ground toward the mobile station,
When the mobile station is in a call, if an opposite mobile station that makes a call on the same channel approaches, the mobile station that forcibly disconnected the mobile station that entered the pre-blocking zone of the other party's call channel first within a certain time In addition, the mobile communication system stops the voice signal pre-blowing and makes the voice interruption minute when one of the mobile stations is handed over. 4. The mobile station that has previously entered the other party's pre-occlusion zone is subject to forced disconnection, but when the opposite mobile station terminates the call, the controlled telephone exchange device disconnects the opposite mobile station. A mobile communication system that cancels a target and restarts transmission of a voice signal to a forward base station, thereby minimizing voice interruption when the mobile station is handed over.

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