Monitoring and control device, communication system, and local wireless communication device

Abstract

A communication system (100) comprises: an intra-platform communication device (150) that wirelessly transmits target data to a railway vehicle (4) using a public communication network (6); a local wireless communication device (160) that receives the target data from the intra-platform communication device (150) through a system communication path, and transmits the target data to the railway vehicle (4) using a local wireless communication method; and a monitor control device (110) that monitors whether the system communication path is sound and whether the local wireless communication path between the local wireless communication device (160) and the railway vehicle (4) is sound, and when the railway vehicle enters the communication range of the local wireless communication device (160), controls the local wireless communication device (160) to transmit the target data if both the system communication path and the local wireless communication path are sound, and controls the intra-platform communication device (150) to transmit the target data if at least either one of the system communication path and the local wireless communication path is unsound.

Description

communication systems

[0001] The present disclosure relates to communication systems.

[0002] There is a system that acquires data from surveillance equipment such as cameras installed in train stations from trains. In this system, the acquired data is transmitted to a mobile communication device inside the train via a platform communication device installed on the station platform.

[0003] In such systems, there are some parts of the communication path between the on-platform communication device and the mobile communication device that use a wireless communication network. These wireless communication networks include public wireless networks that allow communication over the entire railway line, including within stations, and local wireless networks that are built and operated by railway operators.

[0004] When multiple wireless communication networks are available between the in-home communication device and the mobile communication device, for example, as described in Patent Document 1, the in-home communication device and the mobile communication device store the transmission method and communication status, allowing the in-home communication device and the mobile communication device to automatically select the appropriate wireless communication network.

[0005] Patent No. 3782654

[0006] When a train driver approaches a station platform, he or she checks the safety of the platform using camera or sensor data to ensure safety, safely stops the train, and opens and closes the train doors. Unlike public wireless networks, local wireless networks are not affected by network congestion or failures in other communication areas, enabling highly reliable and high-quality wireless communication. Therefore, it is desirable to switch to a local wireless network when it is available.

[0007] In addition, in order to quickly confirm safety on the platform, it is necessary to quickly switch wireless communication between the mobile communication device and the in-platform communication device from a public wireless network to a local wireless network so that the driver can reliably check safety indications based on camera or sensor data when he or she arrives at the platform.

[0008] Conventional technology discloses a method for managing the connection status of multiple predetermined wireless communication networks between a home communication device and a mobile communication device, and selecting a wireless communication network when a communication request occurs, but does not mention a specific method for checking the connection status.

[0009] Therefore, with conventional technology, if there is a problem with the connection status of the wireless communication network to which you are switching, it is possible that switching to that wireless communication network will result in you not being able to obtain the necessary data at the required time.

[0010] Therefore, one or more aspects of the present disclosure aim to switch the communication network used in a railway vehicle from a public wireless network to a local wireless network, thereby enabling reliable communication.

[0011] A communication system according to one aspect of the present disclosure is characterized in that it includes a public wireless communication device that wirelessly transmits target data, which is data to be transmitted to a railway vehicle, to the railway vehicle using a public communication network; a local wireless communication device that receives the target data from the public wireless communication device via a system communication path formed between the public wireless communication device and the railway vehicle, at least a portion of which is wired, and transmits the target data to the railway vehicle using a local wireless communication method having a communication range that covers at least a portion of the railway vehicle's platform; and a monitoring control device that monitors whether the system communication path is sound and whether a local wireless communication path, which is a communication path using the local wireless communication method between the local wireless communication device and the railway vehicle, is sound, and when the railway vehicle enters the communication range, if both the system communication path and the local wireless communication path are sound, causes the local wireless communication device to transmit the target data, and if at least one of the system communication path and the local wireless communication path is not sound, causes the public wireless communication device to transmit the target data.

[0012] According to one or more aspects of the present disclosure, the communication network used in a railway vehicle can be switched from a public wireless network to a local wireless network, thereby enabling reliable communication.

[0013] FIG. 1 is a block diagram schematically showing the configuration of a mobile communication system according to a first embodiment. FIG. 2 is a block diagram schematically showing the configuration of a monitoring control device according to the first to third embodiments. FIG. 3 is a schematic diagram showing an example of communication path health information according to the first embodiment. (A) and (B) are block diagrams showing an example of a hardware configuration. FIG. 4 is a block diagram schematically showing the configuration of a network switch. FIG. 5 is a block diagram schematically showing the configuration of an in-home communication device. FIG. 6 is a block diagram schematically showing the configuration of a local wireless communication device. FIG. 7 is a block diagram schematically showing the configuration of a mobile communication device. FIG. 8 is a sequence diagram showing the operation of a mobile communication system according to the first embodiment. FIG. 9 is a flowchart showing a process of determining whether or not to switch the communication method from a public wireless method to a local wireless method in the first embodiment. FIG. 10 is a block diagram schematically showing the configuration of a mobile communication system according to a second embodiment. FIG. 11 is a schematic diagram showing an example of communication path health information according to the second embodiment. FIG. 12 is a sequence diagram showing the operation of a mobile communication system according to the second embodiment. FIG. 13 is a flowchart showing a process of determining whether or not to switch the communication method from a public wireless method to a local wireless method in the second embodiment. FIG. 14 is a block diagram schematically showing the configuration of a mobile communication system according to a third embodiment. FIG. 15 is a schematic diagram showing an example of communication path health information according to the third embodiment. 10 is a sequence diagram showing the operation of the mobile communication system according to the third embodiment. FIG. 11 is a flowchart showing a process of determining whether or not to switch the communication method from the public wireless method to the local wireless method in the third embodiment. FIG.

[0014] Embodiment 1. Fig. 1 is a block diagram showing a schematic configuration of a mobile communication system 100 according to embodiment 1. In Fig. 1, the mobile communication system 100 is described as a system used in a control room 1, a station 2, and a railway vehicle 4. The station 2 is provided with a platform 3. The mobile communication system 100 also uses a plurality of wireless communications using a public ground communication station 5 and a public communication network 6.

[0015] The mobile communication system 100 includes a monitoring control device 110, a local communication server 120, network switches 130A and 130B, a camera 140, a home communication device 150, a local wireless communication device 160, a mobile communication device 170, and a camera monitor 180. Since the network switches 130A and 130B have the same configuration, hereinafter, when there is no need to particularly distinguish between the network switches 130A and 130B, each of the network switches 130A and 130B will be referred to as the network switch 130.

[0016] A monitoring and control device 110, a local communication server 120, and a network switch 130A are arranged in the control room 1. In the control room 1, a commander operates the monitoring and control device 110 to monitor the railway vehicles 4.

[0017] The monitoring control device 110 determines whether or not it is possible to switch from the public wireless system to the local wireless system based on the soundness of the communication path. If the switching is possible, the monitoring control device 110 instructs the mobile communication device 170 and the home communication device 150 to switch from the public wireless system to the local wireless system.

[0018] Here, the public wireless system is, for example, a fifth-generation mobile communication system, but is not limited to this. Furthermore, the local wireless system is, for example, a communication system using local 5G, which is a fifth-generation mobile communication system network independently constructed by a company or local government other than a telecommunications carrier. Note that the local wireless system may be an existing system other than the fifth-generation mobile communication system, or may not be an existing system, as long as it is a system capable of high speed, low latency, and multiple simultaneous connections.

[0019] The local communication server 120 relays communications that use the local wireless system. Therefore, when using the local wireless system, communications must pass through the local communication server 120. An example of the local communication server 120 is a core device for local 5G.

[0020] The network switch 130A connects the local communication server 120, the monitoring and control device 110, and the network switch 130B located in the station 2, and forms a communication path between the system established in the station 2 and the system established in the control room 1. One network switch 130A may be located in the station 2, or multiple network switches 130A may form a ring structure.

[0021] Station 2 is provided with a network switch 130B, a camera 140, an in-platform communication device 150, and a local wireless communication device 160. In this example, the camera 140, the in-platform communication device 150, and the local wireless communication device 160 are provided on platform 3 in station 2.

[0022] The network switch 130B is connected to the network switch 130A, the home communication device 150, and the local wireless communication device 160.

[0023] The camera 140 is connected to the in-platform communication device 150 and functions as a target data acquisition device that acquires target data, which is data to be transmitted to the railway vehicle 4. In this example, the camera 140 is installed on the platform 3 of the railway vehicle 4, captures video of the platform 3, and provides video data showing the video to the in-platform communication device 150 as target data.

[0024] The intra-platform communication device 150 is connected to the camera 140, receives video data from the camera 140, and functions as a public wireless communication device that transmits the video data wirelessly to the railway vehicle 4 using the public communication network 6. Here, the intra-platform communication device 150 is connected to the network switch 130B and the camera 140. The intra-platform communication device 150 transmits the video data of the camera 140 to the mobile communication device 170 via the public ground communication station 5 when using a public wireless system, or via the local wireless communication device 160 when using a local wireless system. Station 2 and platform 3 are the station and platform where the railway vehicle 4 arrives, respectively. The station where the railway vehicle 4 arrives is also referred to as the arrival station, and platform 3 where the railway vehicle 4 arrives is also referred to as the arrival platform.

[0025] The local wireless communication device 160 receives video data from the in-home communication device 150 via a system communication path formed between the device and the in-home communication device 150, at least part of which is wired, and transmits the video data to the railway vehicle 4 using a local wireless communication method having a communication range that covers at least part of the platform 3.

[0026] A mobile communication device 170 and a camera monitor 180 are arranged in the railway vehicle 4. The camera monitor 180 is connected to the mobile communication device 170. The mobile communication device 170 receives video data from the camera 140 on the platform 3 and provides the video data to the camera monitor 180. Here, since the mobile communication device 170 is mounted on the railway vehicle 4, sending and receiving data to and from the mobile communication device 170 is synonymous with sending and receiving data to and from the railway vehicle 4.

[0027] The camera monitor 180 is a data processing device that processes target data. Here, the camera monitor 180 displays the image represented by the video data. The crew aboard the railway vehicle 4 uses the camera monitor 180 to check the image represented by the received video data from the camera 140.

[0028] Although the present embodiment uses camera monitor 180, any device other than camera monitor 180 may be used as long as it is a data processing device that can process data sent from camera 140 as a data acquisition device. The data acquisition device may also be a device that acquires audio data, sensor data, etc. other than video data.

[0029] The public ground communication station 5 is connected to a public communication network 6. The in-home communication device 150 and the mobile communication device 170 transmit and receive data to and from the public ground communication station 5 using a public wireless system. The in-home communication device 150 and the mobile communication device 170 can communicate with each other, including the monitoring control device 110, via the public communication network 6. The number of public ground communication stations 5 may be one or more.

[0030] In embodiment 1, the mobile communication device 170 of the railway vehicle 4 can always communicate with the public ground communication station 5, and can communicate with the monitoring control device 110 of the control room 1 and the in-platform communication device 150 of the platform 3 via the public communication network 6.

[0031] 2 is a block diagram showing a schematic configuration of the monitoring control device 110 according to embodiment 1. The monitoring control device 110 includes a communication path health information storage unit 111, a communication path monitoring unit 112, a railway vehicle platform approach determination unit 113, a communication method switching determination unit 114, a communication network connection unit 115, and a public communication unit 116.

[0032] The communication path soundness information storage unit 111 stores communication path soundness information indicating the soundness of the communication path monitored by the communication path monitoring unit 112 .

[0033] Fig. 3 is a schematic diagram showing an example of communication path health information in embodiment 1. Fig. 3 shows a communication path health table 111a as an example of communication path health information in embodiment 1. The communication path health table 111a has a communication path type column 111b and a health column 111c.

[0034] The communication path type column 111b stores communication path types for identifying communication paths monitored by the communication path monitoring unit 112. In the first embodiment, the communication path monitoring unit 112 monitors inter-home server communication paths, local wired communication paths, and local wireless communication paths.

[0035] In Fig. 1, the inter-home server communication path is a communication path that passes through the network switches 130A and 130B between the home intra-communication device 150 and the local communication server 120. In Fig. 1, the local wired communication path is a communication path that passes through the network switches 130A and 130B between the local communication server 120 and the local wireless communication device 160. Here, the inter-home server communication path and the local wired communication path form a system communication path.

[0036] 1, the local wireless communication path is a communication path used when communicating by the local wireless method between the local wireless communication device 160 and the mobile communication device 170. In other words, the local wireless communication path is a communication path using the local wireless method between the local wireless communication device 160 and the railway vehicle 4.

[0037] The health column 111c stores whether the communication path identified in the communication path type column 111b is healthy. For example, when "healthy" is stored in the health column 111c, it indicates that the communication path identified in the communication path type column 111b of the same row is healthy. On the other hand, when "no" is stored in the health column 111c, it indicates that the communication path identified in the communication path type column 111b of the same row is not healthy.

[0038] The communication path health table 111a can indicate the health of the inter-home server communication path, the local wired communication path, and the local wireless communication path.

[0039] 2, the communication path monitoring unit 112 monitors a communication path to be monitored and determines whether the communication path is healthy. The communication path monitoring unit 112 stores the monitoring result in communication path health information.

[0040] For example, in order to identify the soundness of the communication path, the communication path monitoring unit 112 periodically communicates with the target device via the communication network connection unit 115. Specifically, one method for identifying the soundness of the communication path between home servers and the local wired communication path is to acquire topology information held by the network switches 130A and 130B.

[0041] The topology information indicates how devices are adjacent to each other on the network. By combining the topology information with link information indicating whether communication is possible between devices, the communication path monitoring unit 112 can determine the health of the communication path.

[0042] The network switch 130A between the control room 1 and the station 2 may acquire topology information and link information by using, for example, Resilient Protection Ring (RPR), a ring control protocol standardized by IEEE (Institute of Electrical and Electronics Engineers) 802.17. The network switch 130B in the station 2 may acquire topology information and link information by using a protocol for managing topology and links between existing devices, such as Link Layer Discovery Protocol (LLDP), standardized by IEEE 802.1AB. Furthermore, the monitoring and control device 110 may acquire topology information and link information from the network switches 130A and 130B using the Simple Network Management Protocol (SNMP) defined by the Request for Comments (RFC).

[0043] As a method for determining the soundness of the local wireless communication path, for example, the communication path monitoring unit 112 may obtain from the local wireless communication device 160 a determination result as to whether or not communication with the mobile communication device 170 is sound. Specifically, the local wireless communication device 160 observes the reception strength of a signal from the mobile communication device 170, and if the reception strength is equal to or greater than a preset reception strength, determines that communication with the mobile communication device 170 is sound. Note that a conceivable method for the monitoring control device 110 to obtain from the local wireless communication device 160 a determination result as to whether or not communication with the mobile communication device 170 is sound is to use SNMP.

[0044] The railway vehicle platform approach determination unit 113 determines whether the railway vehicle 4 has approached within a set distance to the destination platform 3. When the railway vehicle 4 has approached within the set distance to the platform 3, the railway vehicle platform approach determination unit 113 notifies the communication method switching determination unit 114 that the railway vehicle 4 has approached.

[0045] For example, the railcar platform approach determination unit 113 may determine that the railcar 4 is approaching the platform 3 using known technology such as a track circuit or CBTC (Communications-Based Train Control). Here, the set distance is a distance at which local wireless communication is possible between the mobile communication device 170 and the local wireless communication device 160, and may be set by a dispatcher, for example, or may be a value set from a measured value. In other words, determining that the railcar 4 is approaching the platform 3 is synonymous with determining that the railcar 4 has entered the communication range of the local wireless communication device 160.

[0046] When the communication system switching determination unit 114 receives the notification from the railway vehicle platform approach determination unit 113, it determines whether or not the communication system can be switched from the public wireless system to the local wireless system. If the communication system switching determination unit 114 determines that the switching is possible, it instructs the mobile communication device 170 of the railway vehicle 4 and the intra-platform communication device 150 of the platform 3 to switch to the local wireless system.

[0047] The communication network connection unit 115 is connected to the network switch 130A, and communicates with external devices via the network switch 130A.

[0048] The public communication unit 116 connects to the public communication network 6 and performs communication. For example, the public communication unit 116 transmits a switching instruction from the communication system switching determination unit 114 to the mobile communication device 170 of the railway vehicle 4 via the public communication network 6.

[0049] As described above, the monitoring control device 110 monitors whether the system communication path is sound and whether the local wireless communication path between the local wireless communication device 160 and the railway vehicle 4 is sound, and when the railway vehicle 4 enters the communication range of the local wireless communication device 160, if both the system communication path and the local wireless communication path are sound, the monitoring control device 110 causes the local wireless communication device 160 to transmit video data. On the other hand, if at least one of the system communication path and the local wireless communication path is not sound, the monitoring control device 110 causes the in-home communication device 150 to transmit video data.

[0050] As shown in FIG. 4A , some or all of the communication path monitoring unit 112, the railway vehicle platform approach determination unit 113, and the communication system switching determination unit 114 described above can be configured by a memory 10 and a processor 11 such as a CPU (Central Processing Unit) that executes a program stored in the memory 10. Such a program may be provided via a network or may be provided by being recorded on a recording medium. That is, such a program may be provided as a program product, for example.

[0051] 4(B), some or all of the communication path monitoring unit 112, the railcar platform approach determination unit 113, and the communication system switching determination unit 114 can be configured as a processing circuit 12 such as a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array). As described above, the communication path monitoring unit 112, the railcar platform approach determination unit 113, and the communication system switching determination unit 114 can be configured as a processing circuit network.

[0052] The communication path health information storage unit 111 can be configured by a storage device such as a hard disk drive (HDD), a solid state drive (SSD), a nonvolatile memory, or a volatile memory. The communication network connection unit 115 can be configured by a communication interface (I / F).

[0053] 5 is a block diagram showing a schematic configuration of the network switch 130 according to the first embodiment. The network switch 130 includes a communication unit 131, a communication control unit 132, a device connection unit 133, and a transfer processing unit 134.

[0054] The communication unit 131 is a wired communication I / F that performs wired communication with another adjacent network switch 130. In this case, the communication unit 131 includes two communication connection units 131A and 131B that function as wired communication I / Fs in order to form a ring structure with another network switch 130.

[0055] The communication control unit 132 controls wired communication via a wired communication path by controlling the communication unit 131. For example, when the communication unit 131 forms a ring structure, the communication control unit 132 performs control based on the RPR protocol. Specifically, when a single failure occurs in the wired communication network, the communication control unit 132 performs wired communication via a detour route in 50 msec or less.

[0056] The communication control unit 132 also detects the topology within the ring using a topology discovery function defined by the RPR protocol. The communication control unit 132 can determine which network switch is connected how many hops away in a clockwise direction on the wired communication network, and how many hops away in a counterclockwise direction on the wired communication network, based on the device itself. If a failure occurs in the wired communication network, the communication control unit 132 can recognize the location of the failure in the wired communication network.

[0057] The device connection unit 133 is a communication I / F that can be connected to devices such as the home communication device 150. For example, in the network switch 130A, the device connection unit 133 is connected to the monitoring control device 110 and the local communication server 120. In the network switch 130B, the device connection unit 133 is connected to the home communication device 150 and the local wireless communication device 160.

[0058] The device connection unit 133 can be connected to these devices via, for example, a local area network (LAN). The device connection unit 133 transfers data sent and received via wired communication between the connected devices.

[0059] The transfer processing unit 134 performs a transfer process for frames including data. For example, the transfer processing unit 134 transfers frames acquired from devices connected to the device connection unit 133 to the communication control unit 132. The transfer processing unit 134 also transfers frames from the communication control unit 132 to devices connected to the device connection unit 133. The transfer processing unit 134 exchanges data between the communication control unit 132 and the device connection unit 133.

[0060] As shown in FIG. 4A, some or all of the above-described communication control unit 132, device connection unit 133, and transfer processing unit 134 can be configured by a memory 10 and a processor 11 that executes a program stored in the memory 10. Such a program may be provided over a network or may be provided by being recorded on a recording medium. That is, such a program may be provided as a program product, for example.

[0061] 4B, the communication control unit 132, the device connection unit 133, and the transfer processing unit 134 may be partly or entirely configured by the processing circuit 12. As described above, the communication control unit 132, the device connection unit 133, and the transfer processing unit 134 may be configured by a processing circuit network.

[0062] The communication unit 131 and the device connection unit 133 can be configured using a communication I / F.

[0063] 6 is a block diagram showing a schematic configuration of the home communication device 150 according to the first embodiment. The home communication device 150 includes a public wireless communication unit 151, a communication network connection unit 152, a connection control unit 153, and a device connection unit 154.

[0064] The public wireless communication unit 151 is used to transmit video data when using a public wireless system. Specifically, the public wireless communication unit 151 connects to the public communication network 6 via the public ground communication station 5 shown in Fig. 1 and transmits the video data.

[0065] The communication network connection unit 152 is connected to the network switch 130B outside the home communication device 150 and communicates with the network switch 130B. The communication network connection unit 152 is used for communication with the monitoring control device 110 and for transmitting video data when using the local wireless method.

[0066] The device connection unit 154 is connected to the camera 140 outside the home communication device 150 and communicates with the camera 140. For example, the device connection unit 154 receives video data from the camera 140 and provides the video data to the connection control unit 153.

[0067] The connection control unit 153 is connected to and controls the communication network connection unit 152, the public wireless communication unit 151, and the device connection unit 154. For example, the connection control unit 153 receives the result of the communication system switching determination transmitted from the monitoring control device 110 via the public wireless communication unit 151, and controls whether to continue using the public wireless communication unit 151 for transmitting video data or to switch to the communication network connection unit 152.

[0068] 4A, a part or all of the connection control unit 153 described above can be configured by a memory 10 and a processor 11 that executes a program stored in the memory 10. Such a program may be provided over a network or may be provided by being recorded on a recording medium. That is, such a program may be provided as a program product, for example.

[0069] 4B, the connection control unit 153 may be configured as a processing circuit 12. As described above, the connection control unit 153 may be configured as a processing circuit network.

[0070] The communication network connection unit 152, the public wireless communication unit 151, and the device connection unit 154 can be configured by a communication I / F.

[0071] 7 is a block diagram showing a schematic configuration of the local wireless communication device 160 according to the first embodiment. The local wireless communication device 160 includes a communication network connection unit 161 and a local wireless communication unit 162.

[0072] The communication network connection unit 161 is a wired communication I / F that is connected to the network switch 130B outside the local wireless communication device 160 and communicates with the network switch 130B. For example, the communication network connection unit 161 receives video data from the network switch 130B. The received video data is provided to the local wireless communication unit 162.

[0073] The local wireless communication unit 162 is a wireless communication I / F that performs communication using the local wireless system. For example, when using the local wireless system, the local wireless communication unit 162 transmits video data from the camera 140 provided by the communication network connection unit 161 to the mobile communication device 170.

[0074] 8 is a block diagram showing a schematic configuration of a mobile communication device 170 according to embodiment 1. The mobile communication device 170 includes a public wireless communication unit 171, a local wireless communication function unit 172, a communication control unit 173, and a device connection unit 174.

[0075] The public wireless communication unit 171 is connected to the public communication network 6 via the public terrestrial communication station 5. For example, the public wireless communication unit 171 is connected to the communication control unit 173 and receives video data when using the public wireless system. The public wireless communication unit 171 also receives a switching instruction transmitted from the monitoring control device 110.

[0076] The local wireless communication function unit 172 performs communication using a local wireless system. For example, the local wireless communication function unit 172 is connected to the communication control unit 173 and receives video data when using the local wireless system.

[0077] The communication control unit 173 is connected to and controls the public wireless communication unit 171, the local wireless communication function unit 172, and the device connection unit 174. For example, the communication control unit 173 receives a communication method switching instruction transmitted from the monitoring control device 110, and controls whether to continue using the public wireless communication unit 171 for transmitting video data from the camera 140 or to switch to the local wireless communication function unit 172.

[0078] The device connection unit 174 communicates with other devices outside the mobile communication device 170. For example, the device connection unit 174 is connected to a camera monitor 180 outside the mobile communication device 170 and is used by the camera monitor 180 to communicate with external devices.

[0079] 4A, a part or all of the communication control unit 173 described above can be configured by a memory 10 and a processor 11 that executes a program stored in the memory 10. Such a program may be provided over a network or may be provided by being recorded on a recording medium. That is, such a program may be provided as a program product, for example.

[0080] 4B, the communication control unit 173 may be configured as a processing circuit 12. As described above, the communication control unit 173 may be configured as a processing circuit network.

[0081] The device connection unit 174 can be configured by a communication I / F. The public wireless communication unit 171 and the local wireless communication function unit 172 can also be configured by a wireless communication I / F.

[0082] The operation of the first embodiment will be described. Fig. 9 is a sequence diagram showing the operation of the mobile communication system 100 according to the first embodiment. Fig. 9 shows the operation of the monitoring control device 110 in the first embodiment, in which the communication method is switched from the public wireless method to the local wireless method before the video data of the camera 140 is displayed on the camera monitor 180.

[0083] First, when the railway vehicle 4 comes within a set distance of the platform 3, which is the destination, the railway vehicle platform approach determination unit 113 of the monitoring control device 110 sends an approach notification to the communication method switching determination unit 114 indicating that the railway vehicle 4 is approaching the platform 3 (S10).

[0084] Next, upon receiving the approach notification, the communication system switching determination unit 114 refers to the communication path health information stored in the communication path health information storage unit 111 and determines whether or not the communication system between the mobile communication device 170 and the home communication device 150 can be switched to the local wireless system. The details of this determination process will be described later. Here, the description will be given assuming that the determination result for switching the communication system is yes.

[0085] Next, if the communication system can be switched, the communication system switching determination unit 114 of the monitoring and control device 110 causes the public communication unit 116 to transmit a communication system switching instruction to the mobile communication device 170 via the public communication network 6 (S11). The switching instruction here is an instruction to switch to the local wireless communication system.

[0086] The communication system switching determination unit 114 of the monitoring control device 110 also causes the communication network connection unit 115 to transmit a communication system switching instruction to the home communication device 150 (S12). This communication system switching instruction can be transmitted using, for example, a local wired communication path.

[0087] Next, the communication control unit 173 of the mobile communication device 170 causes the local wireless communication function unit 172 to transmit a communication system switching confirmation to the in-home communication device 150 of the home 3 using the local wireless system (S13). This switching confirmation is transmitted to the in-home communication device 150 via the local wireless communication device 160, the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130B.

[0088] Next, upon receiving the communication system switching confirmation, the connection control unit 153 of the home communication device 150 causes the device connection unit 154 to transmit a communication system switching confirmation response (S14). This switching confirmation response is transmitted to the mobile communication device 170 via the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130B, and the local wireless communication device 160.

[0089] Next, the camera monitor 180 of the railway vehicle 4 causes the mobile communication device 170 to transmit a video data request to the camera 140 (S15). At this time, the communication method used for data transmission is the local wireless communication method if the mobile communication device 170, which transmitted the communication method switching confirmation in step S13, receives a communication method switching confirmation response within a certain time period in step S14. On the other hand, if such a switching confirmation response is not received within the certain time period, the public wireless method is used.

[0090] Here, it is assumed that the switching confirmation response is received within a certain time period. Specifically, the mobile communication device 170 receives the video data request at the device connection unit 174 and provides the video data request to the communication control unit 173. The communication control unit 173 causes the local wireless communication function unit 172 to transmit the video data request to the camera 140 (S16). The local wireless communication unit 162 of the local wireless communication device 160 receives the video data request, and the received video data request is provided from the communication network connection unit 161 to the network switch 130B, and transmitted to the camera 140 via the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130B, and the home communication device 150 (S17).

[0091] Upon receiving the video data request, the camera 140 transmits the video data to the camera monitor 180 (S18). This video data is transmitted to the local wireless communication device 160 via the home communication device 150, the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130B.

[0092] In the local wireless communication device 160, when the communication network connection unit 161 receives the video data, the video data is transmitted from the local wireless communication unit 162 (S19).

[0093] In the mobile communication device 170 of the railway vehicle 4, the local wireless communication function unit 172 receives the video data and provides the video data to the communication control unit 173. The communication control unit 173 causes the device connection unit 174 to transmit the video data to the camera monitor 180 (S20).

[0094] In this way, the mobile communication system 100 can switch the communication method from the public wireless method to the local wireless method and reliably transmit video data from the camera 140 to the camera monitor 180 .

[0095] If the communication system switching determination unit 114 determines in step S10 that it is not possible to switch the communication system, the public wireless system is used as is without switching the communication system. In this case, the camera 140 and the camera monitor 180 transmit and receive the video data request and the video data via the public wireless system.

[0096] FIG. 10 is a flowchart showing the process performed by the communication system switching determination unit 114 of the monitor and control device 110 to determine whether or not to switch the communication system from the public wireless system to the local wireless system.

[0097] The communication system switching determination unit 114 of the monitoring control device 110 determines whether or not an approach notification indicating that the railway vehicle 4 is approaching the platform 3 has been received from the railway vehicle platform approach determination unit 113 (S30). If an approach notification has been received (Yes in S30), the process proceeds to step S31.

[0098] In step S31, the communication system switching determination unit 114 checks the health of the local wireless communication path, the local wired communication path, and the communication path between home servers by referring to the communication path health information stored in the communication path health information storage unit 111, and determines whether all of these communication paths are healthy. If at least one of these communication paths is not healthy (No in S31), the process proceeds to step S32, and if all of these communication paths are healthy (Yes in S31), the process proceeds to step S33.

[0099] In step S32, the communication system switching determination unit 114 determines that switching to the local wireless system is not possible because at least one of the communication paths is not healthy.

[0100] In step S33, the communication system switching determination unit 114 determines that all communication paths are healthy and therefore that switching to the local wireless system is possible.

[0101] Then, the communication system switching determination unit 114 outputs a communication system switching instruction to the mobile communication device 170 and the home communication device 150 (S34).

[0102] As described above, according to embodiment 1, in the communication path between the in-platform communication device 150 on platform 3 and the mobile communication device 170 on railway vehicle 4, a determination is made in advance before a request for video data as to whether or not it is possible to switch to a local wireless method, so that communication can be carried out reliably even if the communication method is switched to the local wireless method.

[0103] Second Embodiment In the first embodiment, the video data from the camera 140 on one platform 3 where the railcar 4 arrives is received, but in the second embodiment, an example will be described in which there are multiple platforms.

[0104] Fig. 11 is a block diagram showing a schematic configuration of a mobile communication system 200 according to a second embodiment. In Fig. 11, the mobile communication system 200 is described as a system used in a control room 1, a station 2, and a railway vehicle 4. In the second embodiment, a plurality of platforms 3A, 3B are provided in the station 2. Note that when there is no need to particularly distinguish between the platforms 3A, 3B, each of the platforms 3A, 3B is referred to as a platform 3. Also, although two platforms 3A, 3B are shown in Fig. 11, three or more platforms 3 may be provided.

[0105] The mobile communication system 200 includes a monitoring control device 210, a local communication server 120, network switches 130A, 130B, cameras 140A, 140B, home communication devices 150A, 150B, local wireless communication devices 160A, 160B, a mobile communication device 170, and a camera monitor 280.

[0106] In the second embodiment, a camera 140A, an in-home communication device 150A, and a local wireless communication device 160A are arranged in a home 3A, and a camera 140B, an in-home communication device 150B, and a local wireless communication device 160B are arranged in a home 3B. However, the configurations of the cameras 140A and 140B, the in-home communication devices 150A and 150B, and the local wireless communication devices 160A and 160B are the same as those of the camera 140, the in-home communication device 150, and the local wireless communication device 160 in the first embodiment.

[0107] In addition, when there is no need to particularly distinguish between each of the cameras 140A and 140B, each of the in-home communication devices 150A and 150B, and each of the local wireless communication devices 160A and 160B, each of the cameras 140A and 140B, each of the in-home communication devices 150A and 150B, and each of the local wireless communication devices 160A and 160B will be referred to as camera 140, in-home communication device 150, and local wireless communication device 160, respectively.

[0108] Furthermore, the local communication server 120, the network switch 130, and the mobile communication device 170 of the mobile communication system 200 according to the second embodiment are similar to the local communication server 120, the network switch 130, and the mobile communication device 170 of the mobile communication system 100 according to the first embodiment. However, the network switch 130B is connected to in-home communication devices 150A and 150B and local wireless communication devices 160A and 160B.

[0109] In the camera monitor 280 of the second embodiment, the crew aboard the railway vehicle 4 can select the video data of the video captured by the multiple cameras 140A, 140B to be displayed on the camera monitor 280. For example, the crew aboard the railway vehicle 4 can select either platform 3A or 3B on the camera monitor 280, and the video shown by the video data from the camera 140 arranged on the selected platform 3 is displayed on the camera monitor 280.

[0110] Here, in embodiment 2, a home ID is assigned to each of homes 3A and 3B as home identification information, which is identification information for identifying home 3, and the home ID makes it possible to identify the camera 140, home communication device 150, and local wireless communication device 160 located on that home 3.

[0111] 2 , the monitoring control device 210 in the second embodiment includes a communication path soundness information storage unit 211, a communication path monitoring unit 212, a railway vehicle platform approach determination unit 213, a communication method switching determination unit 214, a communication network connection unit 115, and a public communication unit 116. The communication network connection unit 115 and the public communication unit 116 of the monitoring control device 210 in the second embodiment are similar to the communication network connection unit 115 and the public communication unit 116 of the monitoring control device 110 in the first embodiment.

[0112] The communication path health information storage unit 211 stores communication path health information indicating the health of the communication path monitored by the communication path monitoring unit 212. In the second embodiment, the communication path monitoring unit 212 monitors the communication paths between each of the intra-home communication devices 150A, 150B and each of the local wireless communication devices 160A, 160B, which are arranged in the multiple homes 3A, 3B. Therefore, the communication path health information in the second embodiment indicates whether the communication paths between each of the intra-home communication devices 150A, 150B and each of the local wireless communication devices 160A, 160B, which are arranged in the multiple homes 3A, 3B, are healthy.

[0113] Fig. 12 is a schematic diagram showing an example of communication path health information in embodiment 2. Fig. 12 shows a communication path health table 211a as an example of the communication path health information. The communication path health table 211a has a communication path type column 211b, a home ID column 211c, and a health column 211d.

[0114] The communication path type column 211b stores communication path types for identifying communication paths monitored by the communication path monitoring unit 212. In the second embodiment, the communication path monitoring unit 212 also monitors the inter-home server communication path, the local wired communication path, and the local wireless communication path. In the second embodiment, a system communication path is formed by combining the inter-home server communication path and the local wired communication path.

[0115] 11, the inter-home server communication path is a communication path that passes through the network switches 130A and 130B between the home communication device 150A and the local communication server 120, or a communication path that passes through the network switches 130A and 130B between the home communication device 150B and the local communication server 120. In Fig. 11, the local wired communication path is a communication path that passes through the network switches 130A and 130B between the local communication server 120 and the local wireless communication device 160A, or a communication path that passes through the network switches 130A and 130B between the local communication server 120 and the local wireless communication device 160B. In FIG. 11, the local wireless communication path is a communication path used when communicating using a local wireless method between local wireless communication device 160A and mobile communication device 170, or a communication path used when communicating using a local wireless method between local wireless communication device 160B and mobile communication device 170.

[0116] The home ID column 211c stores the home ID of the home 3 in which the intra-home communication devices 150A, 150B or the local wireless communication devices 160A, 160B are located. Here, "AAA" indicates home 3A, and "BBB" indicates home 3B.

[0117] The health column 211d stores information indicating whether the communication path identified in the communication path type column 211b and the home ID column 211c is healthy.

[0118] The communication path health table 211a can indicate the health of the inter-home server communication path, the local wired communication path, and the local wireless communication path for each home 3 indicated by a home ID.

[0119] 2, the communication path monitoring unit 212 monitors the communication paths to be monitored in each of the homes 3A and 3B and determines whether the communication paths are healthy. The communication path monitoring unit 212 stores the monitoring results in communication path health information. The specific processing by the communication path monitoring unit 212 is the same as that in the first embodiment.

[0120] The railway vehicle platform approach determination unit 213 determines whether the railway vehicle 4 has approached within a set distance to the destination platform 3 for each platform 3. When the railway vehicle 4 has approached within the set distance to the platform 3, the railway vehicle platform approach determination unit 213 notifies the communication system switching determination unit 214 of the platform ID of the platform 3 that the railway vehicle 4 has approached.

[0121] When the communication system switching determination unit 214 receives the notification from the railway vehicle platform approach determination unit 213, it determines whether or not the communication system can be switched from the public wireless system to the local wireless system. If the communication system switching determination unit 214 determines that the switching is possible, it instructs the mobile communication device 170 of the railway vehicle 4 and the intra-platform communication device 150 of the platform 3, where the camera 140 that acquires the video data is located, to switch to the local wireless system.

[0122] The operation of the second embodiment will be described. Fig. 13 is a sequence diagram showing the operation of the mobile communication system 200 according to the second embodiment. Here, it is assumed that the crew of the railway vehicle 4 requests the display of an image captured by the camera 140B installed on the platform 3B.

[0123] 13 shows the operation of the monitoring control device 210 in embodiment 2 to switch the communication method from the public wireless method to the local wireless method. However, in embodiment 2, unlike embodiment 1, in order to enable the crew to arbitrarily switch the video they wish to acquire, the soundness of the communication paths between the local wireless communication device 160 installed on the platform 3 where the railway vehicle 4 arrives and the mobile communication device 170, as well as the soundness of all communication paths between the local wireless communication device 160 installed on the platform 3 where the railway vehicle 4 arrives and the platform communication devices 150A and 150B in the station 2, is confirmed, and a decision is made to switch to the local wireless method.

[0124] First, when the railway vehicle 4 comes within a set distance of the destination platform 3A, the railway vehicle platform approach determination unit 213 of the monitoring control device 210 notifies the communication method switching determination unit 214 of the platform ID "AAA" of the platform 3A that the railway vehicle 4 has approached (S40).

[0125] Next, upon receiving the home ID, the communication system switching determination unit 214 refers to the communication path health information stored in the communication path health information storage unit 211 and determines whether or not it is possible to switch the communication system between the mobile communication device 170 and the in-home communication devices 150A, 150B to the local wireless system. The contents of this determination process will be described later, but in the second embodiment, unlike the first embodiment, it is determined whether or not it is possible to switch the communication system between the mobile communication device 170 and all of the in-home communication devices 150A, 150B arranged in station 2 to the local wireless system. Here, the description will be given assuming that the determination result for switching the communication system is possible.

[0126] Next, if the communication method can be switched, the communication method switching determination unit 214 of the monitoring control device 210 causes the public communication unit 116 to transmit a communication method switching instruction to the mobile communication device 170 via the public communication network 6 (S41). The switching instruction here is an instruction to switch to the local wireless communication method provided by the local wireless communication device 160A of the platform 3A to which the railcar 4 is approaching, and is assumed to include the platform ID of the platform 3A.

[0127] The communication system switching determination unit 214 of the monitoring control device 210 also causes the communication network connection unit 115 to transmit a communication system switching instruction to all the in-home communication devices 150 (here, the in-home communication devices 150A and 150B) (S42). This communication system switching instruction can be transmitted using, for example, a local wired communication path.

[0128] Next, the communication control unit 173 of the mobile communication device 170 causes the local wireless communication function unit 172 to transmit a communication system switching confirmation using the local wireless system to all of the home communication devices 150 (S43). This switching confirmation is transmitted to the home communication devices 150A and 150B via the local wireless communication device 160A, the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130B.

[0129] Next, upon receiving the communication system switching confirmation, the connection control units 153 of all the home communication devices 150 cause the device connection units 154 to transmit a communication system switching confirmation response (S44). This switching confirmation response is transmitted from the home communication devices 150A and 150B to the mobile communication device 170 via the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130B, and the local wireless communication device 160A.

[0130] Next, the camera monitor 280 of the railway car 4 causes the mobile communication device 170 to transmit a video data request to the camera 140B (S45). At this time, the communication method used for data transmission is the local wireless communication method if the mobile communication device 170, which transmitted the communication method switching confirmation in step S43, receives a communication method switching confirmation response from the in-home communication device 150B within a certain time period in step S44. On the other hand, if such a switching confirmation response is not received within the certain time period, the public wireless method is used.

[0131] Here, it is assumed that the switching confirmation response is received within a certain time period. Specifically, the mobile communication device 170 receives the video data request for home 3B at the device connection unit 174 and provides the video data request to the communication control unit 173. The communication control unit 173 causes the local wireless communication function unit 172 to transmit the video data request to the camera 140B (S46).

[0132] The local wireless communication unit 162 of the local wireless communication device 160A receives the video data request, and the received video data request is given from the communication network connection unit 161 to the network switch 130B, and is transmitted to the camera 140B via the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130B, and the home communication device 150B (S47).

[0133] Upon receiving the video data request, the camera 140B transmits the video data to the camera monitor 280 (S48). This video data is transmitted to the local wireless communication device 160A via the home communication device 150B, the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130B.

[0134] In the local wireless communication device 160A, when the communication network connection unit 161 receives the video data, the video data is transmitted from the local wireless communication unit 162 (S49).

[0135] In the mobile communication device 170 of the railway vehicle 4, the local wireless communication function unit 172 receives the video data and provides the video data to the communication control unit 173. The communication control unit 173 causes the device connection unit 174 to transmit the video data to the camera monitor 280 (S50).

[0136] In this way, mobile communication system 200 can switch the communication method from the public wireless method to the local wireless method and reliably transmit video data from camera 140B to camera monitor 280.

[0137] If communication system switching determination unit 214, which has received the home ID notification in step S40, determines that the communication system cannot be switched, the public wireless system is used as is without switching the communication system. In this case, camera 140B and camera monitor 280 transmit and receive the video data request and the video data using the public wireless system.

[0138] FIG. 14 is a flowchart showing the process performed by the communication system switching determination unit 214 of the monitor and control device 210 to determine whether or not to switch the communication system from the public wireless system to the local wireless system.

[0139] The communication system switching determination unit 214 of the monitoring control device 210 determines whether or not the platform ID of the platform 3 that the railcar 4 has approached has been received from the railcar platform approach determination unit 213 (S60). If a notification of the platform ID has been received (Yes in S60), the process proceeds to step S61.

[0140] In step S61, the communication system switching determination unit 214 checks the health of both the local wired communication path and the local wireless communication path associated with the home ID received in step S60 by referring to the communication path health information stored in the communication path health information storage unit 211, and determines whether both communication paths are healthy. If at least one of these communication paths is not healthy (No in S61), the process proceeds to step S62, and if both communication paths are healthy (Yes in S61), the process proceeds to step S63.

[0141] In step S62, the communication method switching determination unit 214 determines that it is not possible to switch to the local wireless method because at least one of the local wired communication path and the local wireless communication path is not healthy on the platform 3 to which the railway vehicle 4 is approaching.

[0142] In step S63, the communication method switching determination unit 214 determines whether all inter-home server communication paths, which are communication paths between all intra-home communication devices 150 arranged in all homes 3 and the local communication server 120, are sound. If at least one inter-home server communication path is not sound (No in S63), the process proceeds to step S64, and if all inter-home server communication paths are sound (Yes in S63), the process proceeds to step S65.

[0143] In step S64, the communication system switching determination unit 214 determines that it is not possible to switch to the local wireless system because it is unable to acquire video data from the camera 140 located on any of the platforms 3.

[0144] On the other hand, in step S65, the communication system switching determination unit 214 determines that all communication paths are healthy and therefore that switching to the local wireless system can be performed.

[0145] Then, the communication method switching determination unit 214 outputs the platform ID acquired in step S60 and a communication method switching instruction to the mobile communication device 170, and outputs a communication method switching instruction to the platform communication device 150 on platform 3 where the camera 140 capturing the image that the crew of the railway vehicle 4 wants to display is located (S66).

[0146] As described above, in the second embodiment, a plurality of in-home communication devices 150 and a plurality of local wireless communication devices 160 are provided by arranging the in-home communication devices 150 and the local wireless communication devices 160 in association with each of the plurality of homes 3. Then, a plurality of system communication paths are formed between the in-home communication devices 150 and the local wireless communication devices 160, thereby forming a plurality of system communication paths between the plurality of in-home communication devices 150 and the plurality of local wireless communication devices 160.

[0147] When the railway vehicle 4 enters the communication range of a local wireless communication device 160 associated with an arrival platform, which is one of the multiple platforms 3 where the railway vehicle 4 will arrive, and if all system communication paths leading to the local wireless communication device 160 associated with the arrival platform are sound and the local wireless communication path between the local wireless communication device 160 associated with the arrival platform and the railway vehicle 4 is sound, the monitoring control device 210 in the second embodiment causes the local wireless communication device 160 associated with the arrival platform to transmit video data. On the other hand, if at least one of all system communication paths leading to the local wireless communication device 160 associated with the arrival platform and the local wireless communication path between the local wireless communication device 160 associated with the arrival platform and the railway vehicle 4 is not sound, the monitoring control device 210 causes the intra-platform communication device 150 associated with the arrival platform to transmit video data.

[0148] In the second embodiment, a plurality of cameras 140 are connected to each of the plurality of in-home communication devices 150. Each of the plurality of cameras 140 acquires video data of each of the plurality of platforms 3 as target data.

[0149] As explained above, in the second embodiment as well, in the communication path between the in-platform communication device 150 on the platform 3 and the mobile communication device 170 on the railway vehicle 4, a determination is made in advance before a request for video data as to whether or not it is possible to switch to a local wireless system, so that communication can be carried out reliably even if the communication system is switched to a local wireless system.

[0150] In addition, in embodiment 2, by using a railway vehicle ID, which is railway vehicle identification information for identifying a railway vehicle 4, and storing the health of the communication path for each railway vehicle 4 in communication path health information, it is also possible to manage the switching of communication methods for each of multiple railway vehicles 4.

[0151] Embodiment 3. In the second embodiment, video data of video captured by a camera 140 selected from a plurality of cameras 140 arranged on a plurality of platforms 3 provided in one station 2 is received, but in the third embodiment, a case where there are a plurality of stations will be described.

[0152] FIG. 15 is a block diagram schematically illustrating the configuration of a mobile communication system 300 according to a third embodiment. In FIG. 15, the mobile communication system 300 is described as a system used by a control room 1, stations 2A and 2B, and a railway vehicle 4. In the third embodiment, a plurality of stations 2A and 2B are provided with a plurality of platforms 3A and 3B, respectively. Note that, when there is no need to particularly distinguish between the stations 2A and 2B, each of the stations 2A and 2B is referred to as a station 2. Furthermore, when there is no need to particularly distinguish between the platforms 3A and 3B, each of the platforms 3A and 3B is referred to as a platform 3. Furthermore, although FIG. 15 illustrates two stations 2A and 2B and two platforms 3A and 3B, three or more stations 2 or three or more platforms 3 may be provided.

[0153] The mobile communication system 300 includes a monitoring control device 310, a local communication server 120, network switches 130A, 130B, and 130C, cameras 140A and 140B, home communication devices 150A and 150B, local wireless communication devices 160A and 160B, a mobile communication device 170, and a camera monitor 380.

[0154] In the third embodiment, a network switch 130A is provided in the control room 1. A network switch 130B and a platform 3A are provided in a station 2A, and a camera 140A, an intra-home communication device 150A, and a local wireless communication device 160A are provided in the platform 3A. A network switch 130C and a platform 3B are provided in a station 2B, and a camera 140B, an intra-home communication device 150B, and a local wireless communication device 160B are provided in the platform 3B. The intra-home communication device 150A and the local wireless communication device 160A are connected to the network switch 130B, and the intra-home communication device 150B and the local wireless communication device 160B are connected to the network switch 130C. However, the configurations of the network switches 130A, 130B, 130C, the cameras 140A, 140B, the home communication devices 150A, 150B, and the local wireless communication devices 160A, 160B are the same as those of the network switch 130, the camera 140, the home communication device 150, and the local wireless communication device 160 in embodiment 1.

[0155] In addition, when there is no need to particularly distinguish between each of the network switches 130A, 130B, and 130C, each of the cameras 140A and 140B, each of the home communication devices 150A and 150B, and each of the local wireless communication devices 160A and 160B, each of the network switches 130A, 130B, and 130C, each of the cameras 140A and 140B, each of the home communication devices 150A and 150B, and each of the local wireless communication devices 160A and 160B will be referred to as the network switch 130, the camera 140, the home communication device 150, and the local wireless communication device 160, respectively.

[0156] Furthermore, the local communication server 120 and the mobile communication device 170 of the mobile communication system 300 according to the third embodiment are similar to the local communication server 120 and the mobile communication device 170 of the mobile communication system 100 according to the first embodiment.

[0157] In the camera monitor 380 of the third embodiment, the crew aboard the railway vehicle 4 is allowed to select, from the video data captured by the multiple cameras 140A, 140B, the video data to be displayed on the camera monitor 380. For example, the crew aboard the railway vehicle 4 selects, on the camera monitor 380, either the combination of station 2A and platform 3A or the combination of station 2B and platform 3B, and the video shown by the video data from the camera 140 located on platform 3 included in the selected combination is displayed on the camera monitor 380.

[0158] In the third embodiment, a station ID is assigned to each of stations 2A and 2B as station identification information that is identification information for identifying station 2, and a platform ID is assigned to each of platforms 3A and 3B as platform identification information that is identification information for identifying platform 3. The station ID and platform ID make it possible to identify the cameras 140, platform communication devices 150, and local wireless communication devices 160 that are located at station 2 and platform 3.

[0159] 2 , the monitoring control device 310 in the third embodiment includes a communication path soundness information storage unit 311, a communication path monitoring unit 312, a railway vehicle platform approach determination unit 313, a communication method switching determination unit 314, a communication network connection unit 115, and a public communication unit 116. The communication network connection unit 115 and the public communication unit 116 of the monitoring control device 310 in the third embodiment are similar to the communication network connection unit 115 and the public communication unit 116 of the monitoring control device 110 in the first embodiment.

[0160] The communication path health information storage unit 311 stores communication path health information indicating the health of the communication path monitored by the communication path monitoring unit 312. In the third embodiment, the communication path monitoring unit 312 monitors the communication paths between each of the in-home communication devices 150A, 150B and each of the local wireless communication devices 160A, 160B, which are arranged on a plurality of platforms 3A, 3B provided in a plurality of stations 2A, 2B. Therefore, the communication path health information in the third embodiment indicates whether the communication paths between each of the in-home communication devices 150A, 150B and each of the local wireless communication devices 160A, 160B, which are arranged on a plurality of platforms 3A, 3B in a plurality of stations 2A, 2B, are healthy.

[0161] Fig. 16 is a schematic diagram showing an example of communication path health information in embodiment 3. Fig. 16 shows a communication path health table 311a as an example of the communication path health information. The communication path health table 311a has a communication path type column 311b, a station ID column 311c, a platform ID column 311d, and a health column 311e.

[0162] The communication path type column 311b stores communication path types for identifying communication paths monitored by the communication path monitoring unit 312. In the third embodiment, the communication path monitoring unit 312 also monitors the inter-home server communication path, the local wired communication path, and the local wireless communication path. In the third embodiment, a system communication path is formed by combining the inter-home server communication path and the local wired communication path.

[0163] 15, the inter-home server communication path is a communication path that passes through the network switches 130A and 130B between the home communication device 150A and the local communication server 120, or a communication path that passes through the network switches 130A and 130C between the home communication device 150B and the local communication server 120. In Fig. 15, the local wired communication path is a communication path that passes through the network switches 130A and 130B between the local communication server 120 and the local wireless communication device 160A, or a communication path that passes through the network switches 130A and 130C between the local communication server 120 and the local wireless communication device 160B. In FIG. 15, the local wireless communication path refers to the communication path used when communicating using the local wireless method between the local wireless communication device 160A and the mobile communication device 170, or the communication path used when communicating using the local wireless method between the local wireless communication device 160B and the mobile communication device 170.

[0164] The station ID column 311c stores the station ID of station 2 where platform 3 is located. Here, "XXX" indicates station 2A, and "YYY" indicates station 2B.

[0165] The home ID column 311d stores the home ID of the home 3 in which the intra-home communication devices 150A, 150B or the local wireless communication devices 160A, 160B are located. Here, "AAA" indicates home 3A, and "BBB" indicates home 3B.

[0166] The health column 211e stores whether the communication path identified in the communication path type column 311b, the station ID column 311c, and the platform ID column 311d is healthy.

[0167] The communication path health table 311a can indicate the health of the home server communication path, the local wired communication path, and the local wireless communication path for each combination of station 2 indicated by the station ID and platform 3 indicated by the platform ID.

[0168] 2 , the communication path monitoring unit 312 monitors the communication path to be monitored for each combination of station 2 and platform 3, and determines whether the communication path is healthy. The communication path monitoring unit 312 stores the monitoring results in communication path health information. The specific processing by the communication path monitoring unit 312 is the same as that in the first embodiment.

[0169] The railway vehicle platform approach determination unit 313 determines whether the railway vehicle 4 has approached within a set distance to platform 3 of station 2, which is the destination, for each combination of station 2 and platform 3. When the railway vehicle 4 has approached within the set distance to platform 3 of station 2, the railway vehicle platform approach determination unit 313 notifies the communication method switching determination unit 314 of the station ID and platform ID of platform 3 of station 2 that the railway vehicle 4 has approached.

[0170] When the communication system switching determination unit 314 receives a notification from the railway vehicle platform approach determination unit 313, it determines whether or not the communication system can be switched from the public wireless system to the local wireless system. If the communication system switching determination unit 314 determines that the switching is possible, it instructs the mobile communication device 170 of the railway vehicle 4 and the on-platform communication device 150 on the platform 3 of the station 2, where the camera 140 that acquires the video data is located, to switch to the local wireless system.

[0171] The operation of the third embodiment will be described. Fig. 17 is a sequence diagram showing the operation of the mobile communication system 300 according to the third embodiment. Here, it is assumed that the railway vehicle 4 arrives at the platform 3A of the station 2A, and the crew of the railway vehicle 4 requests the display of the video captured by the camera 140B installed on the platform 3B of the station 2B.

[0172] 17 shows the operation of the monitoring control device 310 in embodiment 3 to switch the communication method from the public wireless method to the local wireless method. However, unlike embodiment 1, embodiment 3 allows the crew to arbitrarily switch the video they wish to acquire by checking the soundness between the local wireless communication device 160 installed on the platform 3 where the railway vehicle 4 arrives and the mobile communication device 170, as well as the soundness of all communication paths between the local wireless communication device 160 installed on the platform 3 where the railway vehicle 4 arrives and the on-platform communication devices 150A and 150B in the station 2, and then determines whether to switch to the local wireless method.

[0173] First, when the railway vehicle 4 comes within a set distance of platform 3A of station 2A, which is the destination station, the railway vehicle platform approach determination unit 313 of the monitoring control device 310 notifies the communication method switching determination unit 314 of the station ID of station 2A, "XXX", and the platform ID of platform 3A, "AAA" (S70).

[0174] Next, upon receiving the notification of the station ID and platform ID, the communication system switching determination unit 314 refers to the communication path health information stored in the communication path health information storage unit 311 and determines whether or not it is possible to switch the communication system between the mobile communication device 170 and the in-platform communication devices 150A, 150B to the local wireless system. The contents of this determination process will be described later, but in the third embodiment, unlike the first embodiment, it is determined whether or not it is possible to switch the communication system between the mobile communication device 170 and all of the in-platform communication devices 150A, 150B arranged in station 2 to the local wireless system. Here, the description will be given assuming that the determination result for switching the communication system is possible.

[0175] Next, if the communication method can be switched, the communication method switching determination unit 314 of the monitoring control device 310 causes the public communication unit 116 to transmit a communication method switching instruction to the mobile communication device 170 via the public communication network 6 (S71). The switching instruction here is an instruction to switch to the local wireless communication method provided by the local wireless communication device 160A located on platform 3A of station 2A to which the railcar 4 is approaching, and is assumed to include the station ID of station 2A and the platform ID of platform 3A.

[0176] The communication system switching determination unit 314 of the monitoring control device 310 also causes the communication network connection unit 115 to transmit a communication system switching instruction to all the in-home communication devices 150 (here, the in-home communication devices 150A and 150B) (S72). This communication system switching instruction can be transmitted using, for example, a local wired communication path.

[0177] Next, the communication control unit 173 of the mobile communication device 170 causes the local wireless communication function unit 172 to transmit a communication system switching confirmation to all of the home communication devices 150 using the local wireless system (S73). This switching confirmation is transmitted to the home communication device 150A via the local wireless communication device 160A, the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130B. This switching confirmation is also transmitted to the home communication device 150B via the local wireless communication device 160A, the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130C.

[0178] Next, upon receiving the communication system switching confirmation, the connection control units 153 of all the home communication devices 150 cause the device connection units 154 to transmit a communication system switching confirmation response (S74). This switching confirmation response is transmitted from the home communication device 150A to the mobile communication device 170 via the network switch 130B, the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130B, and the local wireless communication device 160A. Furthermore, this switching confirmation response is transmitted from the home communication device 150B to the mobile communication device 170 via the network switch 130C, the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130B, and the local wireless communication device 160A.

[0179] Next, the camera monitor 380 of the railway car 4 causes the mobile communication device 170 to transmit a video data request to the camera 140B (S75). At this time, the communication method used for data transmission is the local wireless communication method if the mobile communication device 170, which transmitted the communication method switching confirmation in step S73, receives a communication method switching confirmation response from the in-home communication device 150B within a certain time period in step S74. On the other hand, if such a switching confirmation response is not received within the certain time period, the public wireless method is used.

[0180] Here, it is assumed that the switching confirmation response is received within a certain time period. Specifically, the mobile communication device 170 receives a request for video data of platform 3B of station 2B at the device connection unit 174, and provides the video data request to the communication control unit 173. The communication control unit 173 causes the local wireless communication function unit 172 to transmit the video data request to the camera 140B (S76).

[0181] The local wireless communication unit 162 of the local wireless communication device 160A receives the video data request, and the received video data request is given from the communication network connection unit 161 to the network switch 130B, and then transmitted to the camera 140B via the network switch 130A, the local communication server 120, the network switch 130A, the network switch 130C and the home communication device 150B (S77).

[0182] Upon receiving the video data request, the camera 140B transmits the video data to the camera monitor 380 (S78). This video data is transmitted to the local wireless communication device 160A via the home communication device 150B, the network switch 130C, the network switch 130A, the local communication server 120, the network switch 130A, and the network switch 130B.

[0183] In the local wireless communication device 160A, when the communication network connection unit 161 receives the video data, the video data is transmitted from the local wireless communication unit 162 (S79).

[0184] In the mobile communication device 170 of the railway vehicle 4, the local wireless communication function unit 172 receives the video data and provides the video data to the communication control unit 173. The communication control unit 173 causes the device connection unit 174 to transmit the video data to the camera monitor 380 (S80).

[0185] In this way, mobile communication system 300 can switch the communication method from the public wireless method to the local wireless method and reliably transmit video data from camera 140B to camera monitor 380.

[0186] If the communication system switching determination unit 314, which has received the station ID and platform ID notification in step S70, determines that the communication system cannot be switched, the public wireless system is used as is without switching the communication system. In this case, the camera 140B and the camera monitor 380 transmit and receive the video data request and the video data using the public wireless system.

[0187] FIG. 18 is a flowchart showing the process performed by the communication system switching determination unit 314 of the monitor and control device 310 to determine whether or not to switch the communication system from the public wireless system to the local wireless system.

[0188] The communication system switching determination unit 314 of the monitoring control device 310 determines whether or not it has received the station ID and platform ID of the platform 3 of the station 2 that the railcar 4 has approached from the railcar platform approach determination unit 313 (S90). If it has received the notification of the station ID and platform ID (Yes in S90), the process proceeds to step S91.

[0189] In step S91, the communication system switching determination unit 314 refers to the communication path health information stored in the communication path health information storage unit 311, checks the health of both the local wired communication path and the local wireless communication path associated with the combination of the station ID and platform ID received in step S90, and determines whether both communication paths are healthy. If at least one of these communication paths is not healthy (No in S91), the process proceeds to step S92, and if both communication paths are healthy (Yes in S91), the process proceeds to step S93.

[0190] In step S92, the communication method switching determination unit 314 determines that it is not possible to switch to the local wireless method because at least one of the local wired communication path and the local wireless communication path is not healthy at the station 2 and platform 3 to which the railway vehicle 4 is approaching.

[0191] In step S93, the communication method switching determination unit 314 determines whether all inter-home server communication paths, which are communication paths between all intra-home communication devices 150 located in all stations 2 and platforms 3 and the local communication server 120, are sound. If at least one inter-home server communication path is not sound (No in S93), the process proceeds to step S94, and if all inter-home server communication paths are sound (Yes in S93), the process proceeds to step S95.

[0192] In step S94, the communication method switching determination unit 314 determines that it is not possible to switch to the local wireless method because it is not possible to acquire video data from the camera 140 located on any of the platforms 3.

[0193] On the other hand, in step S95, the communication system switching determination unit 314 determines that all communication paths are healthy and therefore that switching to the local wireless system can be performed.

[0194] Then, the communication method switching determination unit 314 outputs the station ID and platform ID acquired in step S90 and a communication method switching instruction to the mobile communication device 170, and outputs a communication method switching instruction to the on-platform communication device 150 at station 2 and platform 3 where the camera 140 capturing the image that the crew of the railway vehicle 4 wants to display is located (S96).

[0195] As described above, in the third embodiment, the in-home communication devices 150 and the local wireless communication devices 160 are arranged in association with each of the multiple platforms of the multiple stations, thereby providing multiple in-home communication devices 150 and multiple local wireless communication devices 160. Furthermore, by forming a system communication path between the in-home communication devices 150 and the local wireless communication devices 160, multiple system communication paths are formed between the multiple in-home communication devices 150 and the multiple local wireless communication devices 160.

[0196] When the railway vehicle 4 enters the communication range of the local wireless communication device 160 associated with the arrival platform, which is one of the multiple platforms 3 where the railway vehicle 4 will arrive, and if all system communication paths leading to the local wireless communication device 160 associated with the arrival platform are sound and the local wireless communication path between the local wireless communication device 160 associated with the arrival platform and the railway vehicle 4 is sound, the monitoring control device 310 in the third embodiment causes the local wireless communication device 160 associated with the arrival platform to transmit video data to the local wireless communication device 160 associated with the arrival platform. On the other hand, if at least one of all system communication paths leading to the local wireless communication device 160 associated with the arrival platform and the local wireless communication path between the local wireless communication device 160 associated with the arrival platform and the railway vehicle 4 is not sound, the monitoring control device 310 causes the intra-platform communication device 150 associated with the arrival platform to transmit video data.

[0197] In the third embodiment, a plurality of cameras 140 are connected to each of the plurality of in-home communication devices 150. Each of the plurality of cameras 140 acquires video data of each of the plurality of platforms 3 as target data.

[0198] As explained above, in the third embodiment as well, in the communication path between the on-platform communication device 150 at station 2 and platform 3 and the mobile communication device 170 of the railway vehicle 4, a determination is made in advance as to whether or not it is possible to switch to the local wireless method before sending a video data request, so that communication can be carried out reliably even if the communication method is switched to the local wireless method.

[0199] In addition, in embodiment 3, by using a railway vehicle ID, which is railway vehicle identification information for identifying a railway vehicle 4, and storing the health of the communication path for each railway vehicle 4 in communication path health information, it is also possible to manage the switching of communication methods for each of multiple railway vehicles 4.

[0200] REFERENCE SIGNS LIST 1 control room, 2 station, 3 platform, 4 railway vehicle, 5 public ground communication station, 6 public communication network, 100, 200, 300 mobile communication system, 110, 210, 310 monitoring control device, 120 local communication server, 130 network switch, 140 camera, 150 in-platform communication device, 160 local wireless communication device, 170 mobile communication device, 180 camera monitor.

Claims

1. A monitoring and control device that determines whether or not it is possible to switch between a public wireless communication device that wirelessly transmits target data, which is data to be transmitted to a railway vehicle, to the railway vehicle using a public communication network, and a local wireless communication device that receives the target data from the public wireless communication device via a system communication path formed between the public wireless communication device and the system communication path, at least a portion of which is wired, and transmits the target data to the railway vehicle using a local wireless communication method having a communication range that covers at least a portion of the platform of the railway vehicle, a communication path monitoring unit that monitors whether the system communication path is sound or not, and whether a local wireless communication path that is a communication path using the local wireless communication method between the local wireless communication device and the railway vehicle is sound or not; a communication system switching determination unit that, when the railway vehicle enters the communication range, if both the system communication path and the local wireless communication path are sound, causes the local wireless communication device to transmit the target data, and, if at least one of the system communication path and the local wireless communication path is not sound, causes the public wireless communication device to transmit the target data. A monitoring and control device characterized by the above.

2. the public wireless communication device and the local wireless communication device are arranged in association with each of a plurality of homes, thereby forming a plurality of system communication paths between the plurality of public wireless communication devices and the plurality of local wireless communication devices; When the railway vehicle enters the communication range of the local wireless communication device associated with an arrival platform, which is one of the plurality of platforms where the railway vehicle will arrive, if all system communication paths leading to the local wireless communication device associated with the arrival platform are sound and the local wireless communication path between the local wireless communication device associated with the arrival platform and the railway vehicle is sound, the communication system switching determination unit causes the local wireless communication device associated with the arrival platform to transmit the target data, and if at least one of the plurality of system communication paths and the local wireless communication path between the local wireless communication device associated with the arrival platform and the railway vehicle is not sound, causes the communication system switching determination unit to transmit the target data to the public wireless communication device associated with the arrival platform. The monitoring and control device according to claim 1 ,

3. the public wireless communication device and the local wireless communication device are arranged in association with each of a plurality of platforms of a plurality of stations, thereby forming a plurality of system communication paths between the plurality of public wireless communication devices and the plurality of local wireless communication devices; When the railway vehicle enters the communication range of the local wireless communication device associated with an arrival platform, which is one of the multiple platforms where the railway vehicle will arrive, if all system communication paths leading to the local wireless communication device associated with the arrival platform are sound and the local wireless communication path between the local wireless communication device associated with the arrival platform and the railway vehicle is sound, the communication system switching determination unit causes the local wireless communication device associated with the arrival platform to transmit the target data, and if at least one of the multiple system communication paths and the local wireless communication path between the local wireless communication device associated with the arrival platform and the railway vehicle is not sound, causes the public wireless communication device associated with the arrival platform to transmit the target data. thing The monitoring and control device according to claim 1 ,

4. A monitoring control device according to claim 1, the public wireless communication device, and the local wireless communication device. A communication system comprising:

5. Further comprising a target data acquisition device that is connected to the public wireless communication device and acquires target data that is data to be transmitted to the railway vehicle.

5. The communication system according to claim 4, wherein:

6. The target data acquisition device is installed on the platform and acquires video data obtained by capturing an image of the platform as the target data.

6. The communication system according to claim 5,

7. The local wireless communication device observes the reception strength of the signal from the railway vehicle, and if the reception strength is equal to or greater than a predetermined reception strength, causes the monitoring control device to determine that the system communication path is sound.

7. A communication system according to claim 4, wherein:

8. A monitoring control device according to claim 2 or 3, the public wireless communication device, and the local wireless communication device. A communication system comprising:

9. Further, a plurality of target data acquisition devices are connected to the plurality of public wireless communication devices, respectively, and acquire target data that is data to be transmitted to the railway vehicle.

9. The communication system according to claim 8, wherein:

10. Each of the plurality of target data acquisition devices is installed on each of the plurality of platforms, and acquires video data obtained by capturing video of each of the plurality of platforms as the target data.

10. The communication system according to claim 9, wherein:

11. The local wireless communication device observes the reception strength of the signal from the railway vehicle, and if the reception strength is equal to or greater than a predetermined reception strength, causes the monitoring control device to determine that the system communication path is sound.

9. The communication system according to claim 8, wherein:

12. A local wireless communication device that receives target data, which is data to be transmitted to a railway vehicle, from a public wireless communication device that transmits the target data wirelessly to the railway vehicle using a public communication network via a system communication path, at least part of which is wired, formed between the public wireless communication device and the local wireless communication device, and transmits the target data to the railway vehicle using a local wireless communication method having a communication range that covers at least part of the platform of the railway vehicle, a local wireless communication unit that transmits the target data to the railway vehicle when the local wireless communication method is used; a monitoring control device that determines whether switching between the public wireless communication device and the local wireless communication device is possible monitors whether the system communication path is sound and whether a local wireless communication path, which is a communication path using the local wireless communication method between the local wireless communication device and the railway vehicle, is sound, and when the railway vehicle enters the communication range, if both the system communication path and the local wireless communication path are sound, causes the local wireless communication device to transmit the target data, and if at least one of the system communication path and the local wireless communication path is not sound, causes the public wireless communication device to transmit the target data; The local wireless communication unit monitors the reception strength of the signal from the railway vehicle, and if the reception strength is equal to or greater than a preset reception strength, causes the monitoring and control device to determine that the system communication path is sound. A local wireless communication device comprising: