JP2013162405A - Communication device and failure detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a device which is out of order.SOLUTION: A communication device of the present invention is connected by wire to each of radio repeater devices disposed on a predetermined route and having a radio communication interface, which are each disposed at intervals at which they can communicate by radio with adjacent other radio repeater devices on the route. The communication device comprises storage means, receiving means, and determination means. The storage means stores therein for each radio repeater device identification information for identifying the radio repeater devices correlated with positions on the route at which the radio repeater devices are disposed. The receiving means receives from some of the radio repeater devices communication result information indicating whether communication with other of the radio repeater devices was performed. The determination means checks the communication result information received from some of the radio repeater devices identified by a position where one of the radio repeater devices is located and by identification information correlated by the storage means with positions within a radio communicable range, and, if the result that communication with the one of the radio repeater devices was performed is not included in the communication result information, determines that the one of the radio repeater devices is out of order.

Description

  Embodiments described herein relate generally to a communication device and a failure detection method.

  Conventionally, a control system for controlling various devices using wireless communication has been proposed. In the control system, a wireless relay device called an access point is realized by wirelessly transmitting / receiving information to / from a wireless terminal to be controlled. As a control system, for example, a train control system has recently been proposed. In this train control system, a plurality of wireless relay devices are arranged along the track, and the train is controlled by bidirectionally transmitting and receiving information between the plurality of wireless relay devices and the train to be controlled. To do.

  In such a control system, when a radio signal cannot be received, it is difficult to identify which radio relay device has an abnormality such as a failure.

JP 2009-284423 A

  The problem to be solved by the present invention is to provide a mechanism that makes it easy to identify a wireless relay device in which an abnormality has occurred.

  The communication device according to the embodiment is a wireless relay device having a wireless communication interface arranged on a predetermined route, and is arranged at intervals that allow wireless communication with other wireless relay devices adjacent on the route. Each of the wireless relay devices and the communication device connected by wire includes a storage unit, a reception unit, and a determination unit. The storage unit stores, for each wireless relay device, identification information for identifying the wireless relay device and a position on the route where the wireless relay device is arranged in association with each other. The receiving unit receives communication result information indicating whether or not communication with another wireless relay device has been performed from the wireless relay device. The determination means includes the communication result information received from the wireless relay apparatus identified by the position where one wireless relay apparatus is arranged, the identification information associated with the position within the wirelessly communicable range and the storage means. If the result of communication with the one wireless relay device is not included, it is determined that the one wireless relay device is out of order.

FIG. 1 is a diagram illustrating a configuration example of a train control system according to the first embodiment. FIG. 2 is a block diagram showing a configuration of the first communication device according to the first embodiment. FIG. 3 is a diagram illustrating a table structure of the relay device information storage unit according to the first embodiment. FIG. 4 is a diagram illustrating an example of a Beacon information table storing a Beacon frame received by one wireless relay device according to the first embodiment. FIG. 5 is a diagram illustrating an example of a Beacon information table storing a Beacon frame received by the other wireless relay device according to the first embodiment. FIG. 6 is a flowchart illustrating a procedure of failure determination processing in the first communication device according to the first embodiment. FIG. 7 is a block diagram illustrating a configuration of the first communication device according to the second embodiment. FIG. 8 is a diagram illustrating a table structure of the communication device information storage unit according to the second embodiment. FIG. 9 is a diagram illustrating a table structure of received Beacon information of the wireless relay device according to the second embodiment. FIG. 10 is a diagram illustrating a table structure of received Beacon information of the wireless relay device according to the second embodiment. FIG. 11 is a block diagram illustrating a configuration of the first communication device according to the third embodiment. FIG. 12 is a diagram illustrating failure detection by the network configuration according to the third embodiment. FIG. 13 is a diagram illustrating a network configuration of a train control system according to the third embodiment. FIG. 14 is a block diagram illustrating a configuration of a first communication device according to the fourth embodiment. FIG. 15 is a block diagram illustrating a configuration of a first communication device according to the fifth embodiment. FIG. 16 is a block diagram illustrating a configuration of a wireless relay device according to the sixth embodiment. FIG. 17 is a diagram illustrating a table structure of the relay device information storage unit according to the sixth embodiment. FIG. 18 is a diagram illustrating a hardware configuration of the communication device and the wireless relay device.

(First embodiment)
In the first embodiment, an example applied to a train control system will be described as an example of a control system using wireless communication. FIG. 1 is a diagram illustrating a configuration example of a train control system according to the first embodiment. As shown in FIG. 1, the train control system according to the present embodiment includes a first communication device 101, a second communication device 102, radio relay devices 151 to 155, 161 to 165, and a train 181. Has been.

  The position of the train 181 can be specified based on the information indicating the absolute position stored by the ground unit installed in the track and the rotational speed of the wheel. However, the present embodiment does not limit the method of specifying the position of the train 181 and may use, for example, GPS (Global Positioning System).

  The network of the train control system is configured by an IP (Internet Protocol) network. The first communication device 101, the second communication device 102, the wireless relay devices 151 to 155, 161 to 165, and the train 181 are assigned different MAC addresses and IP addresses in advance. To do. In the present embodiment, communication is performed using UDP (User Datagram Protocol), but other protocols may be used.

  The wired network connecting the wireless relay device and the wireless relay device and between the wireless relay device and the communication device is configured by Ethernet (registered trademark) compliant with IEEE802.3. A wireless network that connects between a wireless relay device and a train is configured by an IEEE802.11 compliant WLAN (Wireless Local Area Network).

  The first communication device 101 is connected to the wireless relay devices 151 to 155 via a wired network. In the present embodiment, an example in which a network configuration connecting a communication device and a plurality of wireless relay devices is a star network will be described, but the present invention is not limited to this network configuration. For example, a communication device and a plurality of wireless relay devices may be connected via a ring network.

  And the 1st communication apparatus 101 transmits / receives information between the trains 181 via the wireless relay apparatuses 151-155.

  The second communication device 102 is connected to the wireless relay devices 161 to 165 via a wired network. And the 2nd communication apparatus 102 transmits / receives information between the trains 181 via the radio relay apparatuses 161-165.

  In the wireless relay devices 151 to 155 and the wireless relay devices 161 to 165, the network configuration of the wireless relay device-wireless relay device is not limited to the network configuration like the wireless relay device-communication device.

  In the train control system shown in FIG. 1, the wireless relay devices 151 to 155 and 161 to 165 are arranged according to the track on which the train 181 travels. The wireless relay devices 151 to 155 and 161 to 165 are arranged at intervals at least capable of communicating with adjacent wireless relay devices. This makes it possible to receive Beacon frames from other adjacent wireless relay devices.

  The Beacon frame includes a MAC address for identifying a wireless relay device that is a transmission source of the frame, a capability of the wireless relay device, a BSS (Basic Service Set) name included in the wireless relay device, and the like. The network group to which the wireless relay device is connected can be identified by the BSS name.

  And the same frequency channel is set to the radio relay apparatuses 151 to 155 and 161 to 165 according to the present embodiment. In the present embodiment, the set frequency channel is Ch1. Therefore, the radio relay apparatuses 151 to 155 and 161 to 165 can receive Beacon frames from other adjacent radio relay apparatuses.

  The wireless relay devices 151 to 155 and 161 to 165 according to the present embodiment include network interfaces for wired communication and wireless communication, and have a function of bridging a wired / wireless network. For example, information transmitted from the train 181 to the communication devices (for example, the first communication device 101 and the second communication device 102) is received by the wireless relay device via the wireless channel. Thereafter, the wireless relay device transmits the information received from the train 181 to the communication device via the wired channel. Thereby, the communication apparatus can receive information from the train 181.

  On the other hand, information transmitted from the communication devices (for example, the first communication device 101 and the second communication device 102) to the train 181 is transmitted to the wireless relay device via a wired channel. Thereafter, the wireless relay device transmits to the train 181 via the wireless channel. Thereby, the train 181 can receive information from the communication device.

  And communication apparatuses, such as the 1st communication apparatus 101 and the 2nd communication apparatus 102, transmit / receive information between the traveling trains 181 via the wireless relay apparatuses 151-155, 161-165. Can do. Furthermore, by performing transmission / reception of information, it is possible to control the running train 181.

  The wireless relay apparatuses 151 to 155 and 161 to 165 have a function of AP (Access Point) in WLAN as a function of the wireless network. According to the AP function, each wireless relay device periodically transmits a Beacon frame. In the present embodiment, each wireless relay device is arranged at a position where it can receive a Beacon frame from another adjacent wireless relay device.

  The wireless relay devices 151 to 155 and 161 to 165 receive the information related to the received Beacon frame from the wireless relay devices located in the wireless communication range (for example, both adjacent), and are connected to the wireless communication device (for example, the first communication device). 1 communication device).

  The train 181 periodically transmits information related to train control such as position information, speed, and train number to the communication device. At this time, as a technique that the train 181 transmits to the communication device, broadcast transmission or multicast transmission may be performed for all communication devices. In addition, the train 181 has a database associated with a communication device capable of communicating with position information on the track, and the communication device to be transmitted is identified and specified according to the position information of the train 181 itself with reference to the database. A method of performing unicast transmission to the communication apparatus may be used.

  In the present embodiment, it is only necessary that information can be transmitted from the train 181 to the communication device, and an implementation method for transmitting information is not limited. The method for acquiring the position information of the train 181 may also grasp the absolute position with a ground element laid on the track, obtain the relative position using a speed generator, or grasp the position using GPS. The position may be grasped by a method other than these methods.

  Next, the communication apparatus will be described. FIG. 2 is a block diagram showing a configuration of the first communication apparatus according to the present embodiment. As illustrated in FIG. 2, the first communication device 101 includes a relay device information storage unit 201, a communication control unit 202, and a determination unit 203. For example, the first communication device 101 is wired to each of the wireless relay devices arranged at intervals that allow wireless communication with other wireless relay devices adjacent on the route. Note that the second communication device 102 has the same configuration as the first communication device 101, and a description thereof will be omitted. Note that each function of the communication control unit and the determination unit included in the communication device is realized by software in the present embodiment, but is not limited to this, and can be configured using hardware as appropriate.

  The relay device information storage unit 201 stores information regarding the wireless relay device for each wireless relay device. FIG. 3 is a diagram showing a table structure of the relay device information storage unit 201 according to the present embodiment. As illustrated in FIG. 3, the relay device information storage unit 201 stores a MAC address, a kilometer distance, an RSSI, a time stamp, and a received Beacon number in association with each other. By referring to the relay device information storage unit 201, the communication device can grasp the position of the wireless relay device and which wireless relay device is connected to which communication device.

  The MAC address is identification information for identifying the wireless relay device on the network. “XX.XX.XX.XX.XX.11” is a MAC address indicating the wireless relay device 151. “XX.XX.XX.XX.XX.12” is a MAC address indicating the wireless relay device 152. “XX.XX.XX.XX.XX.13” is a MAC address indicating the wireless relay device 153. “XX.XX.XX.XX.XX.14” is a MAC address indicating the wireless relay device 154. “XX.XX.XX.XX.XX.15” is a MAC address indicating the wireless relay device 155.

  The kilometer indicates a distance from a predetermined station and is information indicating a position on a track (route). RSSI (Received Signal Strength Indication) indicates the signal strength of the Beacon frame received by the other radio relay apparatus from the radio relay apparatus. The time stamp indicates the time at which another wireless relay device last received a Beacon frame from the wireless relay device. The received Beacon number indicates the total number of Beacon frames received by the other radio relay apparatuses from the radio relay apparatus.

  The communication control unit 202 includes a transmission control unit 211 and a reception control unit 212, and transmits / receives data to / from other devices connected via a network. Other devices serving as transmission / reception destinations include the second communication device 102 in addition to the wireless relay devices 151 to 155. Furthermore, it may be a communication terminal used by a user via a wired network.

  The communication control unit 202 receives the position information and speed information of the train 181 periodically transmitted from the train 181, and the train 181 can travel based on the position information and speed information received from the train 181. Notify the range.

  The reception control unit 212 receives communication result information regarding Beacon frames received from other wireless relay devices from the wireless relay devices 151 to 155. In the present embodiment, as an example of communication result information indicating whether or not communication with another wireless relay apparatus has been performed, an example using information related to a Beacon frame will be described, but other information may be used.

  The determination unit 203 determines whether each of the wireless relay devices 151 to 155 has failed based on the communication result information received from the wireless relay devices 151 to 155 and the relay device information storage unit 201.

  The determination unit 203 according to the present embodiment has a kilometer (position) of one wireless relay device, a kilometer (position) within a wirelessly communicable range, and an IP address associated with the relay device information storage unit 201. If the communication result information received from the plurality of wireless relay devices does not include the information of the Beacon frame received from the one wireless relay device, the one wireless relay device is out of order. Is determined. The determination unit 203 according to this embodiment determines at least communication between two wireless relay devices adjacent to the one wireless relay device in order to determine whether or not the single wireless relay device is out of order. Determine based on the result information.

  When the transmission control unit 211 determines that the determination unit 203 is out of order, the transmission control unit 211 notifies the communication terminal of the user (not shown) connected via the network. As a result, the user can immediately recognize which radio relay device is out of order. Note that the determination result indicating whether or not a failure has occurred is not limited to transmission, and may be output to a display device (not shown). As the output of the determination result, any output method may be used as long as the user can recognize that a failure has occurred.

  Returning to FIG. 1, the failure detection procedure performed when the wireless relay device 153 fails in the train control system according to the present embodiment will be described.

  In the example illustrated in FIG. 1, the wireless relay device 152 is arranged at a position where the Beacon frame transmitted by the wireless relay device 154 can be received, in addition to the adjacent wireless relay device 151 and the wireless relay device 153.

  And the radio relay apparatuses 151-155, 161-165 are provided with the table for hold | maintaining the received Beacon frame. Each radio relay apparatus demodulates a Beacon frame received from another radio relay apparatus, and then obtains a transmission source address, time stamp information, and the like from the demodulated information, and associates the received signal strength with a table. Remember.

  FIG. 4 is a diagram illustrating an example of a Beacon information table that stores a Beacon frame received by the wireless relay device 152. As shown in FIG. 4, in the Beacon information table, the MAC address, RSSI, time stamp, and received Beacon number are associated with each other. The MAC address is an address that identifies the wireless relay device that transmitted the Beacon frame. The wireless relay device 152 stores information on the received Beacon frame (hereinafter also referred to as reception Beacon information) in the Beacon information table shown in FIG.

  The information stored in the wireless relay device may be other than the information described above. For example, the Beacon information table may include load information in the BSS, connected STA information, the number of STAs, and the like. Further, the information held by the wireless relay device is not limited to the information received from the adjacent wireless relay device, but may be information related to the Beacon frame received from, for example, two adjacent wireless relay devices.

  When the wireless relay device 153 is out of order, the Beacon frame cannot be transmitted from the wireless relay device 153, so the Beacon information table of the wireless relay device 152 has the MAC address “XX.XX.XX.XX.XX.11” (wireless There are entries regarding the Beacon frame received from the relay device 151) and “XX.XX.XX.XX.XX.14” (wireless relay device 154), but “XX.XX.XX.XX.XX.13” There is no entry related to the Beacon frame received from (wireless relay apparatus 153).

  Then, the wireless relay device 152 refers to the Beacon information stored in the Beacon information table, and transmits the information of the entry whose reception Beacon number is “100” to the first communication device 101. Thereafter, the wireless relay device 152 resets the received Beacon number of the entry. In the present embodiment, the case where the number of received Beacons for transmission to the first communication apparatus 101 is 100 has been described, but other numerical values may be used. Furthermore, the transmission is not limited according to the number of received Beacon received from each of the wireless relay devices, and the total number of received Beacon received from a plurality of wireless relay devices becomes a predetermined value (for example, 100). You may control to transmit in a case. Further, when the number of received Beacon of one entry becomes “100”, all the information stored in the Beacon information table may be transmitted.

  As a form other than the present embodiment, the trigger for transmitting to the first communication apparatus 101 may be made a condition other than the number of received Beacons. For example, the wireless relay device may have a timer, and the received Beacon information may be transmitted every time a fixed time elapses with the timer. As another example, the connected first communication apparatus 101 may request the reception relay information from the wireless relay apparatus 152. The first communication apparatus 101 may use an existing protocol such as SNMP (Simple Network Management Protocol) as a command for requesting received Beacon information to each wireless relay apparatus. Moreover, you may implement | achieve with original software.

  Similarly, the wireless relay device 154 according to the present embodiment transmits the received Beacon information of the wireless relay device located in the communicable range to the first communication device 101. In the example illustrated in FIG. 1, the wireless relay device 154 is arranged at a position where the wireless relay device 161 can receive the Beacon frame in addition to the adjacent wireless relay device 153 and the wireless relay device 155.

  FIG. 5 is a diagram illustrating an example of a Beacon information table that stores Beacon frames received by the wireless relay device 154. As shown in FIG. 5, in the Beacon information table, the MAC address, RSSI, time stamp, and received Beacon number are associated with each other. The wireless relay device 154 stores information on the received Beacon frame (received Beacon information) in the Beacon information table shown in FIG.

  When the wireless relay device 153 is out of order, the Beacon frame cannot be transmitted from the wireless relay device 153, so the Beacon information table of the wireless relay device 154 has the MAC address “XX.XX.XX.XX.XX.15” (wireless There are entries about the Beacon frame received from the relay device 155) and “XX.XX.XX.XX.XX.16” (wireless relay device 161), but “XX.XX.XX.XX.XX.13” There is no entry related to the Beacon frame received from (wireless relay apparatus 153).

  Then, the wireless relay device 154 refers to the Beacon information stored in the Beacon information table, and transmits the information of the entry whose received Beacon number is “100” to the first communication device 101. Thereafter, the wireless relay device 154 resets the received Beacon number of the entry. In the present embodiment, the case where the number of received Beacons for transmission to the first communication apparatus 101 is “100” has been described, but other numerical values may be used. Furthermore, the trigger for transmission is not limited to the number of received Beacons, and other methods may be used as in the wireless relay device 152 described above.

  As described above, the wireless relay devices 152 and 154 periodically transmit the received Beacon information to the first communication device 101. Then, the first communication apparatus 101 has failed or has a high possibility of malfunctioning based on the received Beacon information (hereinafter, “failed” means “possibility of malfunctioning” It is assumed that there is a wireless relay device. In the present embodiment, the timing of determination is set to a fixed time interval, at the start of business, and at the end of business when receiving Beacon information from the wireless relay device. In addition, this embodiment does not restrict | limit the timing which performs determination, What is necessary is just to be performed at an appropriate timing according to the aspect.

  Then, the first communication device 101 refers to the relay device information storage unit 201, recognizes the position of the wireless relay device, and then fails based on the received Beacon information received from the wireless relay device. It is determined whether or not.

  In the present embodiment, the wireless relay device is arranged at a position where communication can be performed from the adjacent wireless relay devices on the track. Therefore, when one wireless relay device (for example, the wireless relay device 153) is operating normally, the adjacent wireless relay devices (for example, the wireless relay devices 152, 154) are transmitted from the one wireless relay device. Receive Beacon frames. In other words, when the one wireless relay device is out of order, the adjacent wireless relay devices (for example, the wireless relay devices 152 and 154) are not connected to the Beacon frame in the wireless relay device located on both sides of the wireless relay device. Cannot be received. Therefore, the first communication device 101 according to the present embodiment determines whether or not the wireless relay device is out of order based on this condition.

  That is, the determination unit 203 of the first communication apparatus 101 according to the present embodiment adds the wireless relay apparatus 153 (located next to the wireless relay apparatuses 152 and 154) to the received Beacon information received from the wireless relay apparatuses 152 and 154. If the information regarding the Beacon frame received from is not included, it is determined that the wireless relay device 153 is out of order.

  In the present embodiment, the determination unit 203 determines that a wireless relay device that does not include received Beacon information from both adjacent wireless relay devices is a failure. In the present embodiment, since the radio relay device is arranged at every communicable interval along the line, a plurality of radio relay devices are provided for one radio relay device except for the radio relay devices arranged at both ends of the line. Can send and receive information. Thereby, the determination unit 203 can determine whether one wireless relay device is out of order based on the received Beacon information from the plurality of wireless relay devices. Thereby, improvement of determination accuracy can be aimed at.

  Next, failure determination processing in the first communication apparatus 101 according to the present embodiment will be described. FIG. 6 is a flowchart showing the above-described processing procedure in the first communication apparatus 101 according to the present embodiment.

  First, the reception control unit 212 receives reception Beacon information from each of the wireless relay devices 151 to 155 connected by wire (step S601). In the present embodiment, the radio relay apparatuses 151 to 155 transmit the received Beacon information to the first communication apparatus 101 every time the Beacon frame is received 100 times.

  Then, the determination unit 203 determines whether a predetermined time has elapsed since the start of business or the previous determination, or whether the business end time has been reached (step S602). When it is determined that the predetermined time has elapsed or the business end time has not been reached (step S602: No), the process waits until the predetermined time has elapsed or the business end time has been reached. In the present embodiment, the determination is performed when a predetermined time has elapsed or when the business has ended. However, the determination timing is not limited, and may be, for example, when a Beacon frame is received or at the start of work.

  On the other hand, when the determination unit 203 determines that the predetermined time has passed or the business end time has come (step S602: Yes), a plurality of wireless relay devices including both neighbors are received based on the received received Beacon information. It is determined whether any one or more of the wireless relay apparatuses receive the Beacon frame a plurality of times or continuously for a predetermined time (step S603). If it is determined that the signal is received a plurality of times or continuously for a certain period of time (step S603: Yes), the wireless relay device is determined not to have failed, and the process proceeds to step S606.

  On the other hand, when the determination unit 203 determines that all of the plurality of wireless relay devices have not received a plurality of times or continuously for a certain time from one wireless relay device (step S603: No), the Beacon frame is transmitted. It is determined that the one wireless relay device that is supposed to be out of order (step S604).

  Then, the transmission control unit 211 notifies the user (the terminal used by the user) that the one wireless relay device is out of order (step S605).

  Thereafter, the determination unit 203 determines whether or not the failure determination has been completed for all the wireless relay devices (step S606). If the failure determination has not ended (step S606: No), the process starts from step S603.

  On the other hand, when the determination unit 203 determines that the failure determination has been completed for all the wireless relay devices (step S606: Yes), the processing is performed again from step S601. In the case of the end of business, all processing is ended.

  By the way, in wireless communication, it is difficult to always receive Beacon frames correctly continuously and continuously due to fading and noise effects even when the line of sight is secured. For this reason, if the determination unit 203 determines that the wireless relay device that is the transmission source of the Beacon frame is out of order when the Beacon frame cannot be received once by chance, an erroneous determination may be made. Thus, as a failure determination method of the determination unit 203 according to the present embodiment, a failure is determined only when a plurality of wireless relay apparatuses cannot receive a plurality of times or continuously for a predetermined time. Thereby, the accuracy of failure detection can be further increased.

  In the present embodiment, an example has been described in which the determination unit 203 detects whether or not a wireless relay device has failed based on whether or not each wireless relay device has received a Beacon frame. However, the present invention is not limited to the example in which the failure is detected based on the number of times of reception. For example, the strength of the radio wave such as RSSI is used to detect a failure of the wireless relay device, a sign of failure, and a change in the installation environment. May be. For example, when all the RSSIs of the Beacon frame received by a certain wireless relay device are small, there is a possibility that the reception function of the wireless relay device is broken. In addition, if the RSSI of a Beacon frame transmitted from a certain specific wireless relay device is smaller than a predetermined value, there is a possibility of failure of the transmission function of the specific wireless relay device when measured by a plurality of wireless relay devices. . The predetermined value is determined according to the embodiment. In addition, since the position of the wireless relay device is fixed, the average value of RSSI does not change greatly. Therefore, by monitoring the RSSI at regular time intervals and observing the displacement of the average value, it is also possible to read changes in the environment such as a sign of failure and the presence of some shielding object in the wireless relay device feeling.

  In the train control system according to the present embodiment, when the failure detection method is performed during normal business hours, a packet for acquiring failure detection information flows in the network, so the load on the network increases. Therefore, failure detection may not be performed during normal business hours, but may be performed immediately after the system is started before the business is started, immediately before the system is stopped, etc. Thus, by performing failure detection only in a specific situation, it is possible to prevent the system from being greatly affected even if the network bandwidth is consumed.

  In the present embodiment, the example in which the failure determination is performed on the communication device side has been described. However, the failure determination is not limited to the communication device, and any device connected to the wireless relay device by wire may be used. . For example, when the wireless relay device is connected to another wireless relay device by wire, the function of the communication device may be included in one wireless relay device instead of providing a separate device like the communication device. .

  In the communication apparatus according to the present embodiment, the determination as to whether one radio relay apparatus is out of order is performed based on the received Beacon information from a plurality of radio relay apparatuses. The communication apparatus can determine whether or not the wired network is out of order based on whether or not the reception Beacon information is received. Then, based on whether or not the received Beacon information includes information related to the Beacon frame from one wireless relay device, it is determined whether or not the one wireless relay device is out of order. With this method, the communication apparatus can determine which of the wireless network and the wired network is out of order.

(Second Embodiment)
In the first embodiment, the example in which the first communication apparatus 101 performs the failure determination based on the received Beacon information from the wireless relay apparatuses 151 to 155 connected by wire has been described. However, the determination method is not limited to this. Therefore, in the second embodiment, a determination method when a wireless relay device managed by one communication device and a wireless relay device managed by another communication device are adjacent to each other will be described.

  The network configuration of the train control system is the same as that of FIG. 1 shown in the first embodiment, and a description thereof is omitted. In the second embodiment, the processes of the first communication device and the second communication device are different from those of the first embodiment.

  FIG. 7 is a block diagram illustrating a configuration of the first communication device according to the second embodiment. The first communication device 700 according to the present embodiment is different from the first communication device 101 according to the first embodiment described above in that a communication device information storage unit 701 is added and processing is different from the communication control unit 202. The communication control unit 702 is changed, and the determination unit 203 is different from the determination unit 203 in that the process is changed to a determination unit 703. The second communication device has the same configuration as that of the first communication device 700, and a description thereof will be omitted.

  The first communication device 700 according to the present embodiment further uses the received Beacon information from the wireless relay device 161 connected to the second communication device to cause a failure of the wireless relay device (for example, the wireless relay device 155). Is detected. As shown in FIG. 1, the wireless relay device 161 connected to the second communication device is adjacent to the wireless relay device 155. Therefore, the first communication device 700 can improve the detection accuracy of the failure of the wireless relay device 155 by using the received Beacon information of the wireless relay device 161 when detecting the failure of the wireless relay device 155.

  The communication device information storage unit 701 stores information of a communication device that is a request destination of received Beacon information of the first communication device 700. FIG. 8 is a diagram showing a table structure of the communication device information storage unit 701. As illustrated in FIG. 8, the communication device information storage unit 701 stores a device ID, an IP address, a MAC address, and a position in association with each other.

  The device ID is an ID for identifying the requested communication device. The position indicates a relative positional relationship with the first communication device 101 on the line. For example, the position “up” means that it is arranged on the upstream side adjacent to the wireless relay device 151, and the position “down” means that it is located on the downstream side adjacent to the wireless relay device 155. Means that Thereby, by referring to the communication device information storage unit 701, the communication device that is the transmission request destination of the received Beacon information can be specified.

  The communication control unit 702 is changed to a transmission control unit 711 that is different in processing from the transmission control unit 211 and is changed to a reception control unit 712 that is different from the processing in the reception control unit 212 from the communication control unit 202 according to the first embodiment. Different in that it is.

  In addition to the transmission control by the transmission control unit 211 according to the first embodiment, the transmission control unit 711 performs communication with respect to the communication device based on the communication device information stored in the communication device information storage unit 701. A transmission request for the received Beacon information from the wireless relay device managed by the device is transmitted.

  For example, the transmission control unit 711 is located in a range where it can communicate with one wireless relay device (for example, the wireless relay device 155) connected to the first communication device 700 via a wired network, and the first communication. A transmission request for the received Beacon information is transmitted to the second communication device connected to another wireless relay device (for example, the wireless relay device 161) that cannot transmit and receive with the device 700.

  In addition to the transmission control by the reception control unit 212 according to the first embodiment, the reception control unit 712 responds to a transmission request transmitted by the transmission control unit 711 from another communication device (for example, the second communication device). Receiving Beacon information (for example, including information related to the Beacon frame received from the wireless relay device 161).

  The determination unit 703 receives from other wireless relay apparatuses (for example, the second communication apparatus) in addition to the received Beacon information received from the plurality of wireless relay apparatuses 151 to 155 connected to the first communication apparatus 700 by wire. Based on the received Beacon information, it is determined whether one wireless relay device is out of order.

  The train control system according to the present embodiment will be described with reference to FIG. 1 because of the network configuration similar to that of FIG. As shown in FIG. 1, the wireless relay device is arranged at every interval at which a Beacon frame can be received from an adjacent wireless relay device, regardless of the communication device of the connection destination. For this reason, the first communication device 700 according to the present embodiment performs failure detection of the wireless relay device 155 using the received Beacon information of the wireless relay device 161. Hereinafter, a procedure when the wireless relay device 155 is out of order will be described.

  The wireless relay device 154 transmits the received Beacon information of the adjacent wireless relay device to the first communication device 700. As shown in FIG. 1, the wireless relay device 154 can receive the Beacon frame of the wireless relay device 153 and the wireless relay device 155.

  When the wireless relay device 155 is out of order, the wireless relay device 154 cannot receive the Beacon frame from the wireless relay device 155. For this reason, the received Beacon information of the wireless relay device 154 does not include an entry related to the MAC address of the wireless relay device 155. FIG. 9 is a diagram illustrating a table structure of received Beacon information of the wireless relay device 154. As illustrated in FIG. 9, the received Beacon information of the wireless relay device 154 includes only the entry of the wireless relay device 153. Based on the received Beacon information shown in FIG. 9, the wireless relay device 154 transmits the information in the table to the first communication device 700 when the received Beacon number of the wireless relay device 153 becomes “100”. Reset the received Beacon number. The trigger for transmitting the information of the table of the wireless relay device 154 may be other conditions as in the first embodiment.

  Similarly, the wireless relay device 161 adjacent to the wireless relay device 155 also transmits the received Beacon information of the adjacent wireless relay device to the second communication device. In the example illustrated in FIG. 1, the wireless relay device 161 can receive a Beacon frame from the wireless relay device 155 and the wireless relay device 162. However, since the wireless relay device 155 is out of order, the wireless relay device 161 cannot receive the Beacon frame from the wireless relay device 155. For this reason, the reception Beacon information table of the wireless relay device 161 does not include the entry of the MAC address of the wireless relay device 155, and includes only the entry of the wireless relay device 162. FIG. 10 is a diagram illustrating a table structure of received Beacon information of the wireless relay device 161. Based on the received Beacon information shown in FIG. 10, the wireless relay device 161 transmits the information in the table to the second communication device when the number of received Beacon of the wireless relay device 162 becomes “100”, and receives the received Beacon. Reset the number. The trigger for transmitting the information of the table of the wireless relay device 161 may be other conditions as in the first embodiment.

  As described above, the wireless relay device 154 periodically transmits the received Beacon information to the first communication device 700 and the wireless relay device 161 to the second communication device. In addition, each communication device also transmits periodically received Beacon information to adjacent communication devices. In order to transmit to the adjacent communication device, the communication device refers to the communication device information storage unit.

  In the case of the communication device information storage unit 701 stored in the first communication device 700 illustrated in FIG. 8, the 0th communication device is upstream of the first communication device 700, and the second communication device is downstream of the second communication device. It can be recognized that the communication device is connected. The second communication device also holds a communication device information storage unit of the same format. Each communication device transmits received Beacon information to the communication device based on the communication device information storage unit. For example, the first communication device 700 transmits the received Beacon information of the wireless relay devices 151 to 155 to the 0th communication device and the second communication device. Further, the second communication device transmits the received Beacon information of the wireless relay devices 161 to 165 to the first communication device and the third communication device.

  Then, each communication device determines whether there is a malfunctioning wireless relay device using received Beacon information received from another communication device in addition to the received Beacon information received from each wireless relay device. .

  The first communication device 700 can recognize the position where the wireless relay device is installed with reference to the relay device information storage unit 201. When the wireless relay device 155 has not failed, the first communication device 700 recognizes that Beacon from the wireless relay device 155 is notified to at least the wireless relay device 154 and the wireless relay device 161. However, when the wireless relay device 155 is out of order, the first communication device 700 does not receive the received Beacon information from the wireless relay device 155 and receives the received Beacon information from the wireless relay device 154 and the wireless relay device 161. However, the information of the wireless relay device 155 is missing in the received received Beacon information.

  Then, the determination unit 703 of the first communication device 700 determines that a failure occurs when the received Beacon information received from both adjacent wireless relay devices does not include information on the Beacon frame transmitted from the wireless relay device. to decide. Thereby, the determination unit 703 determines that the wireless relay device 155 is out of order.

  On the other hand, the second communication device determines that there is no malfunctioning wireless relay device because there is no wireless relay device with no entry in the Beacon frame in the received Beacon information received from both of the adjacent wireless relay devices. .

  In this way, even when communication devices connected by adjacent wireless relay devices are different, the received Beacon information from the wireless relay device is transmitted and received between the communication devices. Thereby, each communication device can detect a failure of the wireless relay device.

  In the communication device according to the present embodiment, the reception Beacon information can be acquired even when the connection destination of the wireless relay device adjacent to the failure detection target wireless relay device is different from the own device, so that detection accuracy can be improved. it can.

  As described above, the communication device according to the first to second embodiments can detect the failure of the wireless relay device without using the train 181 by performing the above-described determination.

(Third embodiment)
1st-2nd embodiment demonstrated the example which determines the failure of a radio relay apparatus, without using a train. 3rd Embodiment demonstrates the example which detects the failure of a radio relay apparatus using a train.

  FIG. 11 is a block diagram illustrating a configuration of the first communication device according to the third embodiment. The first communication device 1100 according to the present embodiment is changed to a communication control unit 1101 that is different in processing from the communication control unit 702 and the first communication device 700 according to the second embodiment described above. 703 is different from 703 in that the processing is changed to a determination unit 1102 having a different process. The second communication device 1200 has the same configuration as that of the first communication device 1100, and the description thereof is omitted.

  The communication control unit 1101 is changed to a transmission control unit 1111 that is different in processing from the transmission control unit 711 and is changed to a reception control unit 1112 that is different from processing in the reception control unit 712 from the communication control unit 702 according to the second embodiment. Different in that it is.

  When the train 181 including a wireless communication terminal that has a wireless communication interface and moves according to a track is scheduled to move to a predetermined position (for example, position B in FIG. 12), the transmission control unit 1111 has the predetermined position (position B ) To a predetermined wireless relay device (communication relay device 153) existing at a position where communication can be performed wirelessly via the wireless relay device (wireless relay device 151) other than the predetermined wireless relay device. Send to.

  The reception control unit 1112 is based on a communication request transmitted from the transmission control unit 1111 from the train 181 via a wireless relay device (for example, the wireless relay device 154) other than a predetermined wireless relay device (for example, the wireless relay device 153). Then, the communication result information indicating whether or not communication with the predetermined wireless relay device (for example, the wireless relay device 153) has been performed is received.

  The determination unit 1102 is predetermined when the communication result information received from the train 181 does not include a result of communication with a predetermined wireless relay device existing at a position where the train 181 can communicate from a predetermined position. It is determined that the wireless relay device is out of order.

  FIG. 12 is a diagram showing failure detection by the network configuration according to the present embodiment. The network configuration shown in FIG. 12 is the same as the configuration shown in the first and second embodiments.

  In the example shown in FIG. 12, it is assumed that the train 181 is moving. An example in which the first communication device 1100 detects a failure of the wireless relay device 153 will be described. The train 181 periodically transmits position and speed information to the communication device. For this reason, each communication apparatus always knows the position of the train 181 and the like. In addition, as the train 181 moves, information regarding the train 181 under management is periodically transmitted and received between adjacent communication devices.

  For example, the train 181 transmits position information to the first communication device 1100. Thereby, the first communication device 1100 recognizes that the train 181 exists at the point A. Then, (1) the transmission control unit 1111 of the first communication device 1100 transmits a request to make a test connection to the wireless relay device 153 to the train 181 via the wireless relay device 151 when the point B arrives. .

  Thereafter, (2) the train 181 that has received the request makes a test connection to the wireless relay device 153 when reaching the point B. The test connection method is not particularly limited. For example, an IEEE 802.11 STA follows a connection procedure for an AP.

  Thereafter, (3) the train 181 transmits the result of the test connection to the first communication device 1100 via the wireless relay device 155 that is not the wireless relay device 153 at the point C.

  Then, the determination unit 1102 of the first communication device 1100 determines whether or not the wireless relay device 153 has failed based on the test connection result received from the train 181.

  In the present embodiment, an example has been described in which the train 181 performs a test connection and transmits the test result to the communication device.

  In addition, you may combine the detection of the failure using the train 181 concerning this embodiment with the failure detection method shown in the 1st-2nd embodiment. For example, it is conceivable that the train 181 makes a test connection to the wireless relay device detected as a failure by the failure detection method shown in the first to second embodiments.

  In the third embodiment, the communication device instructs the train 181 to perform test connection, and the train 181 transmits the test connection result to the communication device. The communication device according to the third embodiment determines whether or not the wireless relay device is out of order based on the test connection result of the train 181 so that the wireless relay device does not depend on the adjacent wireless relay device. Can be detected.

(Fourth embodiment)
In the first to third embodiments, the case where the frequency channels used by the wireless relay devices are the same has been described. However, in order to avoid interference, a plurality of frequency channels may be used. Therefore, in the fourth embodiment, an example in which every other frequency channel of the wireless relay device is different will be described.

  FIG. 13 is a diagram illustrating a network configuration of the train control system according to the present embodiment. The basic network configuration such as the connection form between the communication device and the wireless relay device will not be described for the same parts as those in the above-described embodiment.

  In the train control system according to the present embodiment, every other frequency channel of the wireless relay device is different. In the example shown in FIG. 13, normally, the frequency channels of the radio relay apparatuses 151, 153, 155, 162, and 164 are set to ch1, and the frequency channels of the radio relay apparatuses 1351, 1352, 1361, 1362, and 1363 are set to ch6. ing. In this network configuration, for example, the radio wave of the radio relay device 153 of ch1 reaches the adjacent radio relay device 1351 and the radio relay device 1352, but is received because the frequency channel of the radio relay device 1351 and the radio relay device 1352 is ch6. It is not possible.

  Therefore, the communication device instructs the wireless relay device connected by the wired network to match the temporarily used frequency channel with the adjacent wireless relay device. When instructing, the communication device may instruct the connected wireless relay device to use channel 1 or channel 6 that was originally used, or for receiving a Beacon frame. An instruction may be given to set another channel 11. The target to be instructed may be all the wireless relay devices connected to the communication device, or may be a specific wireless relay device.

  FIG. 14 is a block diagram illustrating a configuration of a first communication device according to the fourth embodiment. The first communication device 1301 according to the present embodiment is different from the first communication device 700 according to the second embodiment described above in that a channel changing unit 1401 is added and communication control is different from the communication control unit 702. It is different in that it is changed to a part 1402. The second communication device 1302 is assumed to have the same configuration as the first communication device 1301, and the description thereof is omitted.

  The channel changing unit 1401 instructs the wireless relay device to be determined to be the same frequency channel as that of the adjacent wireless relay device via the communication control unit 1402 at the timing of determining whether or not there is a failure. To do.

  The communication control unit 1402 is different from the communication control unit 702 according to the second embodiment in that the communication control unit 1402 is changed to a transmission control unit 1411 that is different in processing from the transmission control unit 711.

  In addition to the transmission control performed by the transmission control unit 702, the transmission control unit 1411 can communicate from the wireless relay device according to an instruction from the channel change unit 1401 when transmitting a request for communication result information to the wireless relay device. A frequency channel change request is transmitted so as to match the frequency channel of the wireless relay device existing at a different position.

  In addition, after the reception control unit 712 receives the received Beacon information, the communication control unit 1402 transmits a change request for changing to the frequency channel before the change to the wireless relay device.

  The wireless relay device that has received an instruction from the first communication device 1301 changes the frequency channel to be used, and receives Beacon information of the adjacent wireless relay device. Then, the first communication device 1301 instructs the wireless relay device, which is the request destination of the frequency channel change, to extract the received Beacon information after a predetermined time from requesting the frequency channel change.

  The wireless relay device that has received the instruction transmits the received Beacon information to the communication device connected by wire. Thereby, the communication device can receive the received Beacon information from the wireless relay device. Thereby, the failure detection of the wireless relay device can be performed as in the above-described embodiment.

  In this embodiment, since the frequency channel used by the wireless relay device is temporarily changed for failure detection, after receiving the received Beacon information, the transmission control unit 1411 of the communication device uses the frequency used by the wireless relay device. The channel needs to be restored. There are various timings for the transmission control unit 1411 to restore the frequency channel used by the wireless relay device. For example, as a trigger that the reception control unit 712 of the communication device has received the received Beacon information, the transmission control unit 1411 may instruct the wireless relay device to return to the original frequency channel. In addition, the wireless relay device may spontaneously return to the original frequency channel after transmitting the received Beacon information to the communication device.

  In the communication apparatus according to the present embodiment, when the received Beacon information of the wireless relay apparatus is extracted, the frequency channel used by the wireless relay apparatus is temporarily changed. For this reason, in a situation where the wireless relay device communicates with the train 181, the train 181 may be unable to communicate. Since each communication device can grasp that the connected wireless relay device and the train 181 are communicating, when each communication device extracts the received Beacon information, it is between the wireless relay device and the train. It is preferable to perform processing so as to detect a failure in a situation where communication is not performed.

  In the train control system according to the present embodiment, the occurrence of interference between adjacent radio relay apparatuses can be normally suppressed by changing the frequency channel. When performing failure detection, the failure detection can be performed by the same processing as in the above-described embodiment by matching the frequency channels.

(Fifth embodiment)
In the embodiment described above, the communication device passively detects a failure of the wireless relay device according to the reception status of the Beacon frame transmitted by the wireless relay device. In the present embodiment, an example will be described in which a communication device actively detects a failure of a wireless relay device without using a Beacon frame.

  The network configuration of this embodiment is the same as that of FIG. The wireless relay device according to the present embodiment has not only an IEEE802.11 compliant AP function but also a STA function. In this embodiment, failure detection is performed using the STA function.

  FIG. 15 is a block diagram illustrating a configuration of a first communication device according to the fifth embodiment. The first communication device 1500 according to the present embodiment is changed to a communication control unit 1501 that is different in processing from the communication control unit 702 and the first communication device 700 according to the second embodiment described above. 703 is different in that the processing is changed to a determination unit 1503 different in processing. The second communication device has the same configuration as that of the first communication device 1500, and a description thereof will be omitted.

  The communication control unit 1501 is different from the communication control unit 702 of the second embodiment in that the transmission control unit 1501 is changed to a transmission control unit 1511 that is different in processing from the transmission control unit 711.

  The transmission control unit 1511 sends a request for establishing a communication link with another wireless relay device (for example, the wireless relay device 153) using the STA function to a wireless relay device (for example, the wireless relay device 1351) adjacent to the other wireless relay device. , 1352). The adjacent wireless relay devices (wireless relay devices 1351 and 1352) are identified by referring to the relay device information storage unit 201.

  The reception control unit 712 indicates whether a communication link has been established with another wireless relay device (for example, the wireless relay device 153) from the wireless relay device (for example, the wireless relay devices 1351 and 1352) that is the transmission destination of the request. Receive connection result information.

  The determination unit 1503 includes a result indicating that a communication link has been established with another wireless relay device (for example, the wireless relay device 153) in the connection result information received from the wireless relay device (for example, the wireless relay devices 1351 and 1352). If not, it is determined that another wireless relay device (for example, the wireless relay device 153) has failed. In the present embodiment, when the determination unit 1503 has not established a communication link with the adjacent wireless relay devices (for example, the wireless relay devices 1351 and 1352), the wireless communication relay device (for example, the wireless relay device 153) is selected. Detects a failure.

  Next, a processing procedure in the present embodiment for detecting a failure will be described. The determination unit 1503 of the first communication device 1500 searches the relay device information storage unit 201 for a wireless relay device adjacent to the wireless relay device 153 in order to detect a failure of the wireless relay device 153. Then, the determination unit 1503 can recognize that the adjacent wireless relay devices of the wireless relay device 153 are the wireless relay device 152 and the wireless relay device 154.

  Therefore, the transmission control unit 1511 transmits an instruction to perform a test connection to the wireless relay device 153 to the wireless relay device 152 and the wireless relay device 154. At that time, the transmission control unit 1511 may transmit the IP address or MAC address of the wireless relay device 153 to the wireless relay devices 152 and 154.

  Receiving the instruction, the wireless relay device 152 tries to connect to the wireless relay device 153 according to the procedure in which the STA in IEEE802.11 connects to the AP. Then, the wireless relay device 152 transmits the connection result to the first communication device 1500.

  Similarly, the wireless relay device 154 tries to connect to the wireless relay device 153. Then, the wireless relay device 154 transmits the connection result to the first communication device 1500.

  The criteria for determining whether the test connection is successful or unsuccessful may be until the authentication procedure is completed, until the association procedure is completed, or until data can actually be transmitted and received, and this embodiment does not impose any restrictions.

  The reception control unit 712 receives connection results for the wireless relay device 153 from both of the wireless relay devices 152 and 154.

  The determination unit 1503 determines that the wireless relay device 153 is faulty when both of the connection results fail. In this embodiment, when the connection result of both of the adjacent wireless relay devices fails, it is determined that the corresponding wireless relay device is faulty. However, when one of the adjacent wireless relay devices fails. The corresponding wireless relay device may be determined as a failure.

  In this embodiment, the transmission control unit 1511 transmits the test connection instruction to both of the adjacent wireless relay apparatuses, but it is not always necessary to transmit the test connection instruction at the same time. An instruction for test connection may be transmitted.

  In this embodiment, the failure detection start timing is not limited, but for example, by applying the failure detection method of this embodiment to all wireless relay devices at the time of system startup, it can be applied to automatic inspection at startup. Is possible. In addition, when an abnormality is detected in the wireless relay device using the failure detection method performed in the first to second embodiments in combination with the first to second embodiments, the failure detection method of this embodiment is used. It may be used. Thereby, failure detection accuracy can be improved.

  In the present embodiment, the wireless relay device has a STA function. Then, the communication device instructs the wireless relay device to connect to another wireless relay device using the STA function. In accordance with the instruction, the wireless relay device temporarily becomes a pseudo train by the TA function, and tries a test connection to the adjacent wireless relay device. By performing the connection, failure detection accuracy can be improved.

(Sixth embodiment)
In the first to fifth embodiments, the communication device detects a failure of the wireless relay device. In the sixth embodiment, a method of detecting a failure of each wireless relay device using only the wireless relay device will be described.

  The network configuration of this embodiment is the same as in FIG. And the radio relay apparatus contained in the train control system concerning this embodiment is demonstrated.

  FIG. 16 is a block diagram illustrating a configuration of a wireless relay device 1600 according to the sixth embodiment. The wireless relay device 1600 illustrated in FIG. 16 includes a relay device information storage unit 1601, a wired communication control unit 1602, a determination unit 1603, and a wireless communication control unit 1604. Then, the wireless relay device 1600 detects a failure of the wireless relay device connected via the wired network.

  The relay device information storage unit 1601 stores information regarding wireless relay devices connected via a wired network. FIG. 17 is a diagram illustrating a table structure of the relay device information storage unit 1601. As illustrated in FIG. 17, the relay device information storage unit 1601 stores the MAC address, RSSI, time stamp, received Beacon number, adjacent flag, and MAC address of another wireless relay device in association with each other. ing. The wireless relay device can grasp other adjacent wireless relay devices by referring to the relay device information storage unit 1601.

  The adjacent flag indicates whether or not the entry is the adjacent wireless relay device. The other wireless relay device is a wireless relay device adjacent to the wireless relay device of the entry, and indicates a MAC address of a wireless relay device different from the wireless relay device 1600.

  In the relay device information storage unit 1601 shown in FIG. 16, since the MAC address is associated with the MAC address of another wireless relay device, the wireless relay device identifies the wireless relay device that is the reception destination of the received Beacon information. it can.

  The relay device information storage unit 1601 is different from the relay device information storage unit 201 according to the first embodiment in that it is included as an adjacent flag whether or not the relay device information storage unit 1601 is a wireless relay device that should always be receivable. The MAC address indicating another wireless relay device adjacent to the receivable wireless relay device is included.

  The wired communication control unit 1602 includes a transmission control unit 1611 and a reception control unit 1612, and transmits / receives data to / from other wireless relay devices connected via a network. The transmitted / received data includes received Beacon information.

  The determination unit 1603 determines whether another wireless relay device is out of order based on the received Beacon information.

  The wireless communication control unit 1604 transmits and receives information to and from the train 181 and a wireless relay device located in a communicable range.

  In the present embodiment, the first wireless relay device 1600 uses the information of the third wireless relay device that is adjacent to the second wireless relay device 1600 to detect a failure of the second wireless relay device that exists between them. Will be described.

  The wireless relay device 1600 detects a failure of the other wireless relay device based on the Beacon frame of the other wireless relay device received by the wireless communication control unit 1604. The flow of failure detection is basically the same as in the first embodiment. The trigger for failure detection may be under any conditions, for example, at the start of work, at the end of business, every predetermined period, when a certain number of Beacon frames are received, or when there is an instruction from the communication device to detect failure And so on.

  When a trigger for performing failure detection occurs, the wireless communication control unit 1604 of the first wireless relay device 1600 receives a Beacon frame from the second wireless relay device adjacent to the device. In addition, referring to FIG. 17, the wireless communication control unit 1604 can recognize that the device receiving the Beacon frame of the second wireless relay device is the third wireless relay device in addition to the own device. .

  Therefore, the transmission control unit 1611 of the first wireless relay device 1600 transmits a transmission request for the received Beacon information received from the second wireless relay device to the third wireless relay device via the wired network.

  The third wireless relay device transmits the received Beacon information received by itself to the first wireless relay device 1600. At this time, the third wireless relay device may transmit all the received reception Beacon information or only the reception Beacon information related to the second wireless relay device.

  Accordingly, the first wireless relay device 1600 can receive the received Beacon information from the third wireless relay device. Thereafter, the determination unit 1603 of the first wireless relay device 1600 receives the received Beacon information from the second wireless relay device based on the received Beacon information and the received Beacon information received by the wireless communication control unit 1604 of the own device. It is determined whether or not the transmitted Beacon frame has been correctly received.

  When the determination unit 1603 cannot confirm the reception of the Beacon frame transmitted by the second wireless relay device in both the first wireless relay device 1600 and the third wireless relay device, the second wireless relay device fails. It is determined that The first wireless relay device 1600 may or may not transmit information regarding the wireless relay device determined to be faulty to the first communication device.

  The wireless relay device 153 may notify the failure of the wireless relay device 154 not only to the first communication device 1500 but also to surrounding wireless relay devices and passing trains.

  In the present embodiment, the method in which the first wireless relay device detects a failure with respect to two adjacent wireless relay devices that can be wirelessly received has been described. However, the failure detection target is not limited to two adjacent wireless relay devices that can be wirelessly received, and failure detection may be performed for other wireless relay devices existing in the network. In this case, the function and operation of the communication device shown in the first to fourth are the same as those implemented in the wireless relay device as they are, and the description thereof is omitted.

  The communication device and the wireless relay device according to the first to second and fourth to sixth embodiments described above can detect a failure of the wireless relay device without using the train 181.

  In the communication apparatuses according to the first to second and fourth to sixth embodiments described above, the failure detection accuracy can be improved by using the reception results of a plurality of wireless relay apparatuses. Furthermore, it is possible to provide a failure detection method that can determine which of the wireless network and the wired network has failed.

  In the embodiment described above, the train control system has been described as an example. However, the present invention is not limited to the train control system, and may be applied to other control systems. Applicable control systems only require that wireless relay devices are arranged according to the route. For example, a control system (for example, ITS (Intelligent Transport System)) relating to a vehicle traveling on a road (route) or a product flows according to the route. You may apply to a control system. Furthermore, it can be used for a smart meter or the like in a smart grid. Like the train security system, these control systems can be monitored from a remote location in real time without requiring an inspector for equipment failure in the network, thereby reducing downtime and costs. Become.

  A hardware configuration of the communication device and the wireless relay device according to the above-described embodiment will be described. FIG. 18 is a diagram illustrating a hardware configuration of the communication device and the wireless relay device. As shown in FIG. 18, the communication device and the wireless relay device include a CPU 1701, a communication I / F 1702, a HDD 1703, a ROM (Read Only Memory) 1704, and a RAM 1705, and a hardware using a normal computer. The hardware configuration. The communication I / F 1702 includes a wired I / F if it is a communication device, and a wired I / F and a wireless I / F if it is a wireless relay device.

  The communication control program executed by the communication apparatus and the wireless relay apparatus according to the present embodiment is a file in an installable format or an executable format, and is a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile). The program is recorded on a computer-readable recording medium such as a disk.

  Further, the communication control program executed by the communication device of this embodiment and the wireless relay device is stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also good. Further, the communication control program executed by the communication device and the wireless relay device of the present embodiment may be provided or distributed via a network such as the Internet.

  Further, the communication control program of the present embodiment may be provided by being incorporated in advance in a ROM or the like.

  The communication control program executed by the communication apparatus and the wireless relay apparatus according to the present embodiment has a module configuration including the above-described units. As actual hardware, the CPU 1701 reads the communication control program from the HDD 1703 and executes it. As a result, the respective units are loaded on the main storage device (RAM 1705), and the respective units are generated on the main storage device (RAM 1705).

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  101, 700, 1100, 1301, 1500 ... first communication device, 102, 1302 ... second communication device, 151-155, 161-165, 1351, 1352 ... wireless relay device, 181 ... train, 201 ... relay device Information storage unit, 202, 702, 1101, 1402, 1501 ... Communication control unit, 203, 703, 1102, 1503 ... Determination unit, 211, 711, 1111, 1411, 1511 ... Transmission control unit, 212, 712, 1112 ... Reception Control unit, 1401 ... Channel change unit, 1600 ... Wireless relay device, 1601 ... Relay device information storage unit, 1602 ... Wired communication control unit, 1603 ... Determination unit, 1604 ... Wireless communication control unit, 1611 ... Transmission control unit, 1612 ... Reception control unit

Claims (7)

Each of the wireless relay devices having a wireless communication interface arranged on a predetermined route, and arranged at every interval capable of wirelessly communicating with other wireless relay devices adjacent on the route, In a wired communication device,
Storage means for storing, in association with each wireless relay device, identification information for identifying the wireless relay device and a position on the route where the wireless relay device is disposed;
Receiving means for receiving communication result information indicating whether or not communication has been performed with another wireless relay device from the wireless relay device;
In the communication result information received from the wireless relay device, identified by the position where one wireless relay device is arranged, the position within a wirelessly communicable range, and the identification information associated with the storage means, A determination unit that determines that the one wireless relay device is faulty when the result of communication with the one wireless relay device is not included;
A communication device comprising: The determination means is received from a plurality of radio relay apparatuses identified by the identification information associated with the position where one radio relay apparatus is arranged, the adjacent position on the route, and the storage means. When the communication result information does not include a result of communication with the one wireless relay device, it is determined that the one wireless relay device is faulty.
The communication apparatus according to claim 1. To another communication device connected to another wireless relay device that is located in a range where communication with the one wireless relay device connected to the communication device can be performed via a wired network and cannot be transmitted to or received from the communication device. On the other hand, the other communication device further includes a transmission means for transmitting the request for the communication result information received from the other wireless relay device,
The receiving unit receives the communication result information corresponding to the request transmitted by the transmitting unit from the other communication device;
The determination means determines whether the one wireless relay device has failed based on the communication result information received from the other wireless relay device in addition to the communication result information received from a plurality of wireless relay devices. To determine,
The communication apparatus according to claim 1 or 2. When the transmission means transmits a request for communication result information to the wireless relay device when different frequency channels are assigned to the wireless relay device, A frequency channel change request is transmitted to match the frequency channel of the radio relay apparatus identified by the associated identification information, and the communication result information is received by the receiving unit and then the frequency channel before the change is received. Send a change request to change,
The communication apparatus according to claim 3. The transmission means transmits a request for establishing a communication link with the one wireless relay device to the wireless relay device identified by the identification information associated with a position where communication with the one wireless relay device is possible. Send to
The receiving means receives communication result information indicating whether or not a communication link has been established with the one wireless relay device from the wireless relay device to which a request for establishing a communication link is established;
The determination means, when the communication result information received from the wireless relay device does not include a result indicating that a communication link with the single wireless relay device has been established, Is determined to be malfunctioning,
The communication apparatus according to any one of claims 1 to 4. Each of the wireless relay devices having a wireless communication interface arranged on a predetermined route, and arranged at every interval capable of wirelessly communicating with other wireless relay devices adjacent on the route, In a wired communication device,
Storage means for storing the identification information for identifying the wireless relay device and the position of the wireless relay device on the route in association with each other, for each wireless relay device;
When a wireless communication terminal that has a wireless communication interface and moves according to the route is scheduled to move to a predetermined position, the identification associated with the position that can be communicated wirelessly from the predetermined position in the storage Transmitting means for transmitting a communication request to a predetermined wireless relay device identified by information to the wireless communication terminal via a wireless relay device other than the predetermined wireless relay device;
Receiving means for receiving, from the wireless communication terminal, communication result information indicating whether communication has been performed based on the communication request via a wireless relay device other than the predetermined wireless relay device;
The communication result information received from the wireless communication terminal does not include a result of communication with the wireless relay device indicated by the identification information associated with a position where communication is possible from the wireless communication terminal Determining means for determining that the wireless relay device is faulty,
A communication device comprising: Each of the wireless relay devices having a wireless communication interface arranged on a predetermined route, and arranged at every interval capable of wirelessly communicating with other wireless relay devices adjacent on the route, In the failure detection method executed by the wired communication device,
The communication device includes a storage unit that stores, for each wireless relay device, identification information for identifying the wireless relay device and a position on the route where the wireless relay device is disposed in association with each other.
A receiving step for receiving, from the wireless relay device, communication result information indicating whether or not communication with another wireless relay device has been performed;
The communication received from the wireless relay device, wherein the determination unit is identified by the identification information associated with the position where one wireless relay device is arranged, the position within a wirelessly communicable range, and the storage unit. A determination step for determining that the one wireless relay device is faulty when the result information does not include a result of communication with the one wireless relay device;
A failure detection method including:

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