JP2018056736A - Radio system for radio type train control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the utilization efficiency of communication resources in handover processing in a radio system for a radio type train control system.SOLUTION: A radio system 6 comprises a plurality of radio base stations 4 (4a, 4b) and an on-board radio station 5. Data is separated to be accommodated in a plurality of slots for communication. The radio base stations 4 have location information on trains. When a train T arrives at a switch permission start point P which has been previously set, the radio base station 4a requests the radio base station 4b as a handover destination to make a slot reservation. When the slot reservation is made by the radio base station 4b, the radio base station 4a notifies the on-board ratio station 5 of the completion of slot reservation. When receiving the notification of the completion of slot reservation, the on-board radio station 5 switches communication with the radio base station 4a being currently in communication to communication with the radio base station 4b as the handover destination regardless of the position of the own train T. Thereby, the time when a reserved slot is not used is reduced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radio system for a radio train control system in a railway.

  2. Description of the Related Art Conventionally, there is known a wireless train control system that communicates control information related to safety between the ground and a vehicle using radio in a railway (see Non-Patent Document 1). As shown in FIG. 1, the wireless train control system 1 is roughly divided into a ground system 2 and an on-board system 3 (see Non-Patent Document 2). The ground system 2 is installed on the ground and includes a command center device 21, a ground device 22, a radio base station 4, and the like. The on-vehicle system 3 is installed on the vehicle and includes an on-vehicle control device 31 and an on-vehicle radio station 5. The command center device 21 is a device that monitors and manages train operation in the control target line section (see Annex B of Non-Patent Document 2). The ground device 22 is a device that performs the train control of the control target line section and the control of the switch, etc. on the ground side. The on-vehicle control device 31 is a device that performs monitoring control of a train to be controlled, and is connected to the ground device 22 via the wireless system 6. The radio system 6 is also called a train radio system, and is a system that provides radio data transmission between the ground device 22 and the on-board controller 31, and includes a radio base station 4 and an on-board radio station 5. The radio base station 4 is connected to the ground device 22 via the ground transmission path, and performs data communication with the on-board radio station 5 by radio. The on-board radio station 5 is connected to the on-board controller 31 and performs data communication with the radio base station 4 by radio.

  In the wireless system 6, one or more wireless base stations 4 are arranged along the line according to the wireless reach distance, and interface with the ground device via the ground transmission path (see 4.2 of Non-Patent Document 2). When a plurality of radio base stations 4 a and 4 b are arranged along the railway line, the radio system 6 is arranged between the ground radio device 41 and the on-board radio device 51 when the train passes the area boundary of the radio base station 4. Handover is performed so that communication can be continuously performed.

  2. Description of the Related Art Conventionally, a radio system that performs handover in a railway is known. In such a wireless system, for example, when the antenna position of the on-board wireless station exceeds the handover point, the wireless base station is switched (for example, see Patent Document 1). In addition, there is a known wireless system that communicates information via a wireless base station beyond a handover point when a wireless communication unit (on-board wireless station) in a vehicle exceeds a handover point (see Patent Document 2). In any radio system, handover is performed at the handover point. The handover point is the same location regardless of the train driving direction, so that the communicable area of the radio base station before the handover and the communicable area of the radio base station of the handover destination overlap (overlapping) ) (See FIG. 3 of Patent Document 1 and FIG. 3 of Patent Document 2).

  In the wireless system 6, data is divided and accommodated in a plurality of slots for communication (see, for example, Patent Document 3). Since data communication is time division, this slot is also called a time slot. The slot is a communication resource (resource) necessary for data communication. In the wireless system 6 of the wireless train control system 1, the data to be communicated includes control information relating to safety. For this reason, as shown in FIG. 4, before the train T reaches the handover point P1, the slot of the handover destination radio base station 4b is reserved at the handover spare point P2 and the handover is performed. The slots are surely assigned to data communication.

  A conventional handover process in the wireless system 6 will be described. The radio base station 4 and the on-board radio station 5 have a terrestrial radio device 41 and an on-vehicle radio device 51, respectively, as data communication transmitting / receiving devices (see FIG. 1). The radio base station 4 and the on-board radio station 5 include a base device 42 and an on-board device 52, respectively, as devices that provide a handover function.

  A conventional handover sequence in the wireless system 6 is shown in FIG. The base unit 42 (42a, 42b) of the radio base station 4 has train position information. When the train T reaches a predetermined handover reserve point P2, the base station 42a of the radio base station 4a before the handover communicates with the handover destination radio base station 4b, that is, the next on-board radio station 5 The ground radio apparatus 41b is determined. Then, the base device 42a requests the next terrestrial radio device 41b to reserve a slot, and also issues a key for communication to the terrestrial radio device 41b. Then, when the slot reservation is completed, the base device 42a transmits the slot reservation completion and parameters for communicating with the next terrestrial radio device 41b to the onboard device 52 of the onboard radio station 5.

  The on-board device 52 receives the completion of the slot reservation, and when the own train T reaches the handover point P1, notifies the terrestrial radio device 41a before the handover of the end of the communication. Communication is started to the handover destination terrestrial radio apparatus 41b at the timing. That is, a handover is performed from the radio base station 4a to the radio base station 4b. Note that the on-board wireless device 51 does not play a role in this handover sequence, and the description of “control communication” in FIG. 5 is communication for controlling the timing of handover.

  The above handover process is described at the level of the radio base station 4 and the on-board radio station 5 as follows. The radio base station 4a has the position information of the train T. When the train T reaches the preset handover reserve point P2, the radio base station 4a requests the handover destination radio base station 4b to reserve the slot, When the reservation is completed, the reservation completion of the slot is transmitted to the onboard radio station 5. The on-board radio station 5 receives communication about the completion of the slot reservation, and when the own train T arrives at the handover point P1, it communicates with the radio base station 4a before the handover (during communication), The communication is switched to the handover destination radio base station 4b.

  However, in such a handover process, after the train T reaches the handover standby point P2, the slot of the handover target radio base station 4b is reserved until reaching the handover point P1, and the reservation is made. Since the used slot is not used for communication, the utilization efficiency of the slot which is a communication resource is not good.

  Furthermore, for example, when an accident occurs and the train stops in a dumpling state, the train concentrates at a certain point, so that slot reservation requests are concentrated at the next radio base station 4b. Further, since the train is stopped, even if the slot of the next terrestrial radio apparatus 41b is reserved, the reserved many slots are not expected to be used for communication for a while. For this reason, the utilization efficiency of the slot which is a communication resource is not remarkably good.

Japanese Patent Laying-Open No. 2015-137079 JP2015-139205A JP 2014-50038 A

JIS E3801-1: 2009 "Wireless train control system-Part 1: General requirements and functional requirements" JIS E 3801-2: 2010 "Wireless train control system-Part 2: System requirements"

  The present invention solves the above problem, and improves the use efficiency of communication resources in a handover process in a wireless system of a wireless train control system that wirelessly communicates control information for controlling a train. Objective.

  A wireless system of the present invention is a wireless system of a wireless train control system that wirelessly communicates control information for controlling a train, and includes a plurality of wireless base stations, and the wireless base station provided on a vehicle. And the on-board radio station that communicates data including the control information between them, the data is divided and accommodated in a plurality of slots, and the radio base station has train position information. When a train arrives at a preset switching permission start point, it requests a slot reservation from the handover destination radio base station, and when the slot reservation is completed, the slot radio station completes the slot reservation. When the on-board radio station receives the completion of the reservation of the slot, the on-board radio station performs communication with the radio base station in communication with the handover destination without using the position of the own train. Communication with the radio base station And switches.

  In this radio system, when the on-board radio station does not receive the completion of the reservation of the slot after the own train has reached the switching permission start point, the on-board radio station determines the communicable area of the radio base station in communication. It is preferable to control the own train so as not to leave.

  In this wireless system, it is preferable that the switching permission start point is set at an area end on the side where a train enters in a communicable area of the handover destination wireless base station.

  In this radio system, the radio base station transmits a key used for data encryption and decryption to the radio base station at the handover destination when requesting the slot reservation to the radio base station at the handover destination. It is preferable.

  According to the radio system of the present invention, when the on-board radio station receives the notification of the completion of the slot reservation, the on-board radio station performs communication with the radio base station in communication without using the position of the own train as a condition. Since the communication is switched to the over-destination radio base station, the time during which the reserved slot is not used is shortened, and the utilization efficiency of the slot which is a communication resource is improved.

The block block diagram of a wireless train control system. The area design drawing of the radio | wireless system which concerns on one Embodiment of this invention. FIG. 3 is a sequence diagram showing a handover sequence in the radio system. The area design drawing of the conventional radio | wireless system. The sequence diagram which shows the handover sequence in the conventional radio | wireless system.

  A wireless system according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a wireless train control system 1 has the same configuration as a conventional wireless train control system defined in Japanese Industrial Standards (Non-Patent Document 1 and Non-Patent Document 2), and is wireless. System 6 is included. The wireless system 6 has the same hardware configuration as that of the conventional wireless system described above, and the handover process is different. Parts equivalent to those of the conventional wireless system are denoted by the same reference numerals.

  The wireless train control system 1 wirelessly communicates control information for controlling a train. The radio system 6 includes a plurality of radio base stations 4 (4a, 4b) and an on-board radio station 5. The on-board radio station 5 communicates data including control information with the radio base station 4. The data is divided and accommodated in a plurality of slots for communication. The radio base station 4 has train position information.

  Each configuration of the wireless train control system 1 will be further described in detail. The command center device 21 is a device that monitors and manages train operation in the control target line section (see Annex B of Non-Patent Document 2). The ground device 22 is a device that performs the train control of the control target line section and the control of the switch, etc. on the ground side. The ground device 22 has hardware such as a processing device and a storage device, and operates by executing software.

  The on-vehicle control device 31 is a device that performs monitoring control of a train to be controlled, and is connected to the ground device 22 via the wireless system 6. The wireless system 6 is a device that provides wireless data transmission between the ground device 22 and the on-board control device 31. The wireless base station 4 of the wireless system 6 is connected to the ground device 22 via the ground transmission path. The on-board radio station 5 of the radio system 6 is connected to the on-board controller 31 and performs data communication with the radio base station 4 by radio.

  The command center device 21, the ground device 22, and the radio base station 4 are called the ground system 2 because they are installed on the ground. Since the on-board control device 31 and the on-board radio station 5 are installed on the vehicle, they are called the on-board system 3.

  In the present embodiment, data communication in the wireless system 6 is time division, so that the slot is also called a time slot. The slot is a communication resource (resource) necessary for data communication.

  As shown in FIG. 2, the train T travels in the right direction of FIG. When the train T reaches the preset switching permission start point P, the radio base station 4a requests the handover destination radio base station 4b to reserve a slot.

  When the radio base station 4a requests the handover-destination radio base station 4b to reserve a slot, the radio base station 4a transmits a key used for data encryption and decryption to the radio base station 4b.

  Then, the radio base station 4a transmits the slot reservation completion to the on-board radio station 5 when the slot reservation of the radio base station 4b is completed.

  When the on-board radio station 5 receives the notification of completion of the slot reservation, the on-board radio station 5 does not use the position of the own train T as a condition, and communicates with the radio base station 4a in communication with the handover destination radio base station. Switch to communication with 4b.

  When the on-board radio station 5 does not receive the completion of the slot reservation after the own train T reaches the switching permission start point P, the own train T does not leave the communicable area of the radio base station 4a in communication. To control the own train.

  The switching permission start point P is set at the end of the area on the side where the train enters in the communicable area of the handover destination radio base station 4b. The area end does not need to be a mathematically exact end, but is a substantial end of the communication area with accuracy in consideration of a train length, a train position detection error, and the like.

  The handover process of the wireless system 6 will be described in further detail. The radio base station 4 and the on-board radio station 5 have a terrestrial radio device 41 (41a, 41b) and an on-board radio device 51 as transmission / reception devices for data communication, respectively (see FIG. 1). The radio base station 4 and the on-board radio station 5 include base apparatuses 42 (42a, 42b) and an on-board apparatus 52 as apparatuses that provide a handover function, respectively.

  The base device 42 of the wireless base station 4 has train position information. As shown in FIG. 2 and FIG. 3, when the train T reaches the preset switching permission start point P, the base device 42a of the radio base station 4a before the handover, That is, the ground radio apparatus 41b with which the on-board radio station 5 communicates is determined next. Since the train T travels in one direction up or down the track, it is easy to determine which radio base station 4 is the handover destination radio base station 4b. The order of the base stations 4 may be determined in advance and stored in the base device 42 and the on-board device 52.

  Then, the base device 42a requests the next terrestrial radio device 41b to reserve a slot via the base device 42b, and also issues a key for communication to the terrestrial radio device 41b. The key is an encryption key.

  Then, when the slot reservation is completed, the base device 42a communicates with the next terrestrial radio device 41b by completing the slot reservation to the onboard device 52 of the onboard radio station 5 via the terrestrial radio device 41a. Communicate the parameters to

  The on-board device 52 allows the own train T to leave the communicable area of the wireless base station 4a in communication and enter the area where communication with the next wireless base station 4b is performed (next). Zone entry permission).

  The on-board device 52 notifies the terrestrial radio device 41a before handover of the end of communication without using the position of the own train T as a condition, and at the next timing to the terrestrial radio device 41b that is the handover destination. Start communication. That is, a handover is performed from the radio base station 4a to the radio base station 4b. The terrestrial radio apparatus 41a before the handover releases the slot when notified of the end of communication. Note that the on-board wireless device 51 does not play a role in this handover sequence, and the description of “control communication” in FIG. 3 is communication for controlling the timing of handover.

  As an exception process, when the on-board device 52 does not receive the completion of the slot reservation after the own train T reaches the switching permission start point P, the on-board device 52 sets the communicable area of the wireless base station 4a in communication to the own train T. The own train T is controlled so as not to appear. That is, the on-board device 52 does not permit next zone entry. Such an exception occurs, for example, when an accident occurs and the train stops in a dumpling state, and slots cannot be reserved for all of those trains.

  In the conventional handover process, after the train T reaches the handover reserve point P2, the slot of the radio base station 4b that is the handover destination is reserved until the handover T reaches the handover point P1, and the slot is reserved. The slot was not used for communication (see FIG. 4). On the other hand, in the wireless system 6 of the present embodiment, when the slot of the handover destination wireless base station 4b is reserved, the handover is performed without using the position of the own train T as a condition. In addition, the time during which the reserved slot is not used is shortened (see FIG. 2).

  Specifically, in the conventional handover process, in the case of a conventional line, the handover reserve point P2 is set to 1 km before the handover point P1, so that if the maximum speed of the train is 120 km / h, The time from when T reaches the handover reserve point P2 to when the handover is performed is about 30 seconds. This time will be longer if the train stops. For a long time, the slot of the reserved handover destination radio base station 4b is not used for communication.

  On the other hand, in the wireless system 6 of the present embodiment, the time until the handover is performed after the train T reaches the switching permission start point P is the base device processing cycle, the wireless device transmission cycle, and the vehicle processing cycle. The maximum is 10 seconds, and the average is about 7 seconds. Therefore, the time during which the reserved slot is not used for communication is 1/3 or less compared to the conventional case.

  As described above, according to the wireless system 6 according to the present embodiment, when the on-board wireless station 5 receives the notification of the completion of the slot reservation, the on-board wireless station 4a is not communicating with the position of the own train T and is communicating. Is switched to communication with the handover-destination radio base station 4b, so that the slot is reserved, the time when the reserved slot is not used is shortened, and the use of the slot which is a communication resource is used. Efficiency is improved.

  When the on-board radio station 5 does not receive the completion of the slot reservation after the own train T reaches the switching permission start point P, the own train T does not leave the communicable area of the radio base station 4a in communication. Since the own train T is controlled as described above, it is possible to prevent the control information for controlling the train T from being communicated.

  Since the switching permission start point P is set at the area end on the side where the train T enters in the communicable area of the handover destination radio base station 4b, the area where the handover process can be performed becomes large.

  When the radio base station 4a requests the handover destination radio base station 4b to reserve a slot, the radio base station 4a transmits a key used for data encryption and decryption to the radio base station 4b, so that communication security is ensured. .

  In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention. For example, the train T may travel in the left direction in FIG. 2, and a handover may be performed from the radio base station 4b to the radio base station 4a. Also, the number of radio base stations 4 may be three or more.

1 Radio train control system 4, 4a, 4b Radio base stations 43a, 43b Communication area 5 On-board radio station 6 Radio system P Switching permission start point T Train

Claims (4)

A wireless system of a wireless train control system that wirelessly communicates control information for controlling a train,
A plurality of radio base stations;
An on-board radio station that is provided on a vehicle and performs communication of data including the control information with the radio base station;
The data is divided and accommodated in a plurality of slots for communication,
The radio base station has train position information, and when the train reaches a preset switching permission start point, it requests the slot reservation from the handover destination radio base station, and the slot reservation is completed. The slot on the vehicle radio station,
When the on-board radio station receives the completion of the slot reservation completion, the on-board radio station performs communication with the radio base station in communication without using the position of the own train as a condition. A wireless system characterized by switching to communication with the network.   If the on-board radio station does not receive the completion of the slot reservation after its own train has reached the start point of the switching permission, the on-board radio station will prevent the own train from leaving the communicable area of the communicating radio base station. The radio system according to claim 1, wherein the train is controlled.   3. The switching permission start point is set at an area end on a side where a train enters in a communicable area of the handover destination radio base station. Wireless system. The radio base station transmits a key used for data encryption and decryption to the radio base station of the handover destination when requesting the slot reservation to the radio base station of the handover destination. The radio system according to any one of claims 1 to 3.

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