Communication control device, communication control method, communication control program, and communication system to which the communication control device is applied

Abstract

When transferring the same application data from both the active and standby communication control devices, the system determines whether the transfer is possible using the device status information of the communication control device and the application data information to be transferred. [Solution] A communication control device comprising a plurality of communication control devices having an active system and a standby system on a communication system sharing a communication channel, includes a communication control device status information acquisition unit that acquires self-communication control device status information indicating the device status of its own communication control device and other communication control device status information indicating the device status of other communication control devices, a data transfer determination unit that determines whether or not to transfer first application data received from an application device, a transmission control unit that transmits the first application data based on the transfer feasibility determination result, and a reception control unit that receives second application data transmitted from the transmitting communication control device, wherein the data transfer determination unit determines whether or not to transfer based on the self-communication control device status information, other communication control device status information and information regarding the transmission of the first application data.

Description

Technical Field

[0001] The present invention relates to a communication control device, a communication control method, a communication control program, and a communication system to which the communication control device is applied.

Background Art

[0002] In recent years, with the spread of networks, applications (hereinafter simply referred to as "apps") and services via the network have been provided. To access these apps and services, there are many systems that use general-purpose wireless communication systems such as LTE (Long Term Evolution) and 5G (5th Generation). As an example, the use of such systems in railway communication systems for the purpose of safe, accurate, and comfortable train operation is currently attracting attention.

[0003] In the current railway communication system, in order to achieve safe, accurate, and comfortable train operation, a dedicated wireless system is utilized, or a siloed wireless system is constructed to satisfy different communication requirements for each of a plurality of apps built on the system. Therefore, high introduction costs and operation costs, and difficulty in cooperation between apps are problems in the current railway communication system. On the other hand, by constructing a railway communication system that utilizes a general-purpose wireless communication system, it is assetless, and a reduction in fixed costs due to zero infrastructure is expected.

[0004] However, in order to use a general-purpose wireless communication system, there are problems that it is a shared network with general users and that there are areas where wireless coverage is not established. That is, when using a general-purpose wireless system, the achievable communication quality changes depending on the location and time, so there is a risk that the communication quality required by the app cannot be guaranteed.

[0005] Therefore, in order to utilize general-purpose wireless systems, a communication platform (hereinafter referred to as "communication control device") with communication control functions that guarantee communication quality for each application is expected. The communication control device referred to here implements communication control such as path redundancy control using multiple communication channels, continuous transmission control and retransmission control that send the same packet multiple times as redundant packets, thereby reducing the degradation of communication quality even in environments where communication quality is insufficient and guaranteeing the communication quality required by the application.

[0006] Therefore, in order to realize a communication system that utilizes a general-purpose wireless communication system requiring high reliability as a communication system in railways, system design including a communication control device is indispensable.

[0007] The communication control system described in Patent Document 1 is a management device that selects a communication path that satisfies the communication requirements of an application, as a technology relating to communication control in a communication control device. It comprises an event detection unit that detects changes in the operation of an application or increases or decreases in the number of applications as events, application information that manages the communication requirements for each operation of an application, communication path information that manages the communication quality for each communication path, and a communication control method calculation unit that determines a communication control method that satisfies the communication requirements of the application for which an event was detected by referring to the application information and the communication path information, and notifies the communication control device. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2023-44932 [Overview of the project] [Problems that the invention aims to solve]

[0009] In general-purpose wireless communication systems, communication resources are managed on a per-wireless terminal basis (e.g., LTE router or mobile phone). For example, when transmitting data from multiple applications to a general-purpose wireless system using the same wireless terminal, if the application data includes a significantly larger amount of communication traffic than the allocated communication resources, the communication resources available to the wireless terminal will be restricted from the standpoint of fairness in the communication system. In other words, it may become difficult for the wireless terminal to transmit the amount of communication traffic required, potentially degrading the communication quality of the application data.

[0010] In a communication system that considers device redundancy by installing multiple communication control devices, path redundancy control must be implemented while considering the amount of communication traffic transmitted by wireless terminals. When multiple communication control devices transmit the same data to wireless terminals, depending on the communication traffic of the application data, even if there are sufficient communication resources on an application-by-application basis, the system as a whole may become insufficient, and the communication quality may actually deteriorate due to the device redundancy. Therefore, the selection of a communication path that transmits excessive communication traffic to wireless terminals due to redundancy should be avoided.

[0011] Furthermore, we consider a system in which multiple communication control devices are classified into active and standby systems, with the active system transmitting application data and the standby system not transmitting application data. In this case, since only the active system transmits data in an environment where there are sufficient communication resources to transmit application data, there will be no degradation in communication quality due to the redundancy of communication control devices. However, if the communication control device of the active system fails, it will be necessary to switch the communication control device of the standby system to the active system, and communication will be interrupted until the switchover is complete.

[0012] In mission-critical applications such as train control, low latency and uninterrupted communication are required, meaning even temporary communication interruptions are unacceptable. Therefore, depending on the application, it may be necessary to select communication paths and perform communication control so that path redundancy control can be implemented from both the active and standby communication control systems.

[0013] The technology described in Patent Document 1 selects an appropriate communication path and performs communication control based on the communication requirements of the application and the communication quality information of the communication path. However, because the communication path is not selected through path redundancy control after the communication control device is multiplexed, a deterioration in communication quality occurs. Furthermore, because the device status information of the active and standby communication control devices is not used for communication path selection, there is a risk that communication will be interrupted because data cannot be switched between the active and standby systems immediately. Therefore, it does not solve problems such as selecting a communication path to transmit excessive communication traffic through path redundancy control in an environment with multiplexed communication control devices, or selecting a communication path that can maintain continuous data transmission even in the standby system for each type of application.

[0014] Therefore, the present invention aims to provide a technology that reduces the degradation of communication quality through path redundancy control in a communication system having multiple communication control devices, which include both active and standby systems, and enables appropriate data transmission for each application request. [Means for solving the problem]

[0015] To solve the above problems, one representative communication control device according to the present invention is a plurality of communication control devices having an active system and a standby system on a communication system that shares a communication path, comprising: a communication control device status information acquisition unit that acquires self-communication control device status information indicating the device status of its own communication control device and other communication control device status information indicating the device status of other communication control devices; a data transfer determination unit that determines whether or not to transfer first application data received from an application device; a transmission control unit that transmits the first application data based on the transfer feasibility determination result; and a reception control unit that receives second application data transmitted from the transmitting communication control device, wherein the data transfer determination unit determines whether or not to transfer based on the self-communication control device status information, other communication control device status information and information regarding the transmission of the first application data. [Effects of the Invention]

[0016] According to the present invention, since the communication path used for path redundancy control can be appropriately selected simultaneously from the active system and the standby system, it is possible to immediately switch the communication control device used for data transmission from the standby system to the active system while suppressing the degradation of communication quality caused by transmitting excessive communication traffic to wireless terminals. Issues, structures, and effects other than those mentioned above will be clarified by the following explanation of the implementation methods. [Brief explanation of the drawing]

[0017] [Figure 1] This block diagram shows an example of the physical configuration of a communication system incorporating the communication control device according to the present invention. [Figure 2] This is a block diagram showing an example of the configuration of a communication control device and a communication management device. [Figure 3] This figure shows an example of a device status display screen shown on the output device of a communication management device. [Figure 4] This figure shows an example of the on-board communication environment settings screen displayed on the output device of a communication management device. [Figure 5] This is a block diagram showing an example of the configuration of a communication control device according to the present invention. [Figure 6] It is a block diagram showing an example of the configuration of the application data transmission device according to the first embodiment. [Figure 7] It is a diagram showing an example of the processing procedure of the other communication control device state acquisition unit of the application data transmission device according to the first embodiment in a flowchart. [Figure 8] It is a diagram showing an example of the processing procedure of the self-communication control device state acquisition unit of the application data transmission device according to the first embodiment in a flowchart. [Figure 9] It is a diagram showing an example of the processing procedure of the data transfer determination unit of the application data transmission device according to the first embodiment in a flowchart. [Figure 10] It is a diagram showing an example of the processing procedure of the transmission control unit of the application data transmission device according to the first embodiment in a flowchart. [Figure 11] It is a block diagram showing an example of the configuration of the application data reception device according to the first embodiment. [Figure 12] It is a diagram showing an example of the processing procedure of the transmission data reception unit of the application data reception device according to the first embodiment in a flowchart. [Figure 13] It is a diagram showing an example of the processing procedure of the reception control unit of the application data reception device according to the first embodiment in a flowchart. [Figure 14] It is a block diagram showing an example of the configuration of the application data transmission device according to the second embodiment. [Figure 15] It is a diagram showing an example of the data configuration stored in the transmission application information DB of the application data transmission device according to the second embodiment. [Figure 16] It is a diagram showing an example of the processing procedure of the transmission application information acquisition unit of the application data transmission device according to the second embodiment in a flowchart. [Figure 17] It is a block diagram showing an example of the configuration of the application data transmission device according to the third embodiment. [Figure 18] It is a diagram showing an example of the processing procedure of the communication quality evaluation unit of the application data transmission device according to the third embodiment in a flowchart. [Figure 19] It is a diagram showing an example of the processing procedure of the data transfer determination unit of the application data transmission device according to the third embodiment in a flowchart. [Figure 20] This is a block diagram showing an example of the configuration of an application data transmission device according to Example 4. [Figure 21] This diagram shows an example of the processing procedure of the monitoring data transmission / reception unit of the application data transmission device according to Embodiment 4, in flowchart form. [Figure 22] This diagram shows an example of the processing procedure of the data transfer determination unit of the application data transmission device according to Embodiment 4, in flowchart form. [Modes for carrying out the invention]

[0018] Examples 1 to 3 will be described below with reference to the drawings as embodiments for carrying out the present invention. However, the present invention is not limited to these embodiments. In the drawings, the same parts are denoted by the same reference numerals. If it is not necessary to describe the components separately, they are described without subscripts (for example, communication control device 102), and if it is necessary to describe the components separately, they are described with subscripts (for example, ground-side communication control device A102-1-1, ground-side communication control device B102-1-2).

[0019] Figure 1 is a block diagram showing an example of the physical configuration of a communication system incorporating the communication control device according to the present invention. The communication system shown in Figure 1 employs a configuration that uses a general-purpose wireless communication system to communicate about train operations and customer service between multiple application devices on the moving vehicle (the part below the wireless terminal shown in Figure 1) and the ground (the part above the internet shown in Figure 1). Furthermore, the communication control device employs a multiplexed configuration. This configuration provides a wireless communication system that enables safe, accurate, and comfortable railway operation. Here, a general-purpose wireless communication system refers to a wireless communication system that is a shared network for general users, but it is not limited to LTE or 5G.

[0020] In a general-purpose wireless communication system, an application device 101-1 and a communication control device 102-1 are installed on the ground side within the service area, and are connected to on-board equipment via the internet 104, core network 105, and wireless network 106. The on-board equipment includes a wireless terminal 107 connected to the wireless network 106, a communication control device 102-2, and an application device 101-2. Furthermore, the communication management device 103 installed on the ground side is connected to the Internet 104.

[0021] The application device 101 is a device that transmits and receives application data using communication control by the communication control device 102, and realizes train operation, customer service, and other functions.

[0022] The communication control device 102 shares device status information with other communication control devices 102 on the ground side, or with other communication control devices 102 on the vehicle side, and performs communication control on application data received from the application device 101. Incidentally, this invention focuses particularly on the communication control device 102 that performs this communication control.

[0023] The communication control by the communication control device 102 performs path redundancy control, for example, in areas where throughput is insufficient, by adopting data transmitted from a communication path with better communication performance. For example, in Figure 1, when the internet 104, core network A105-1, and wireless network A106-1 are used as communication paths, if the application does not meet the communication quality requirements, the communication control device 102 will perform control to adopt data transmitted using the internet 104, core network B105-2, and wireless network B106-2 paths. Here, the communication control devices 102 are not limited to two, and there may be two or more, and the number of communication control devices 102 on the ground side and on the vehicle side do not have to be the same.

[0024] Figure 2 is a block diagram showing an example of the configuration of the communication control device 102 and the communication management device 103. The communication control device 102 consists of a computer having a processor (CPU (Central Processing Unit)) 201, memory 202, auxiliary storage device 204, communication interface 205, input interface 203, and output interface 206. In Figure 2, "interface" is abbreviated as "I / F".

[0025] The processor (CPU) 201 is an arithmetic unit that executes programs stored in memory 202, and realizes the processing of the communication control device 102 by executing various programs (communication control programs that perform the processes shown in the flowcharts described later). Note that some of the processing performed by the processor (CPU) 201 by executing programs may be performed by other arithmetic units (for example, hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array)).

[0026] Memory 202 includes non-volatile memory elements such as ROM (Read Only Memory) and volatile memory elements such as RAM (Random Access Memory). ROM stores immutable programs (e.g., BIOS (Basic Input Output System)). RAM is a high-speed, volatile memory element such as DRAM (Dynamic Random Access Memory) that temporarily stores programs executed by the processor (CPU) 201 and data used during program execution.

[0027] The auxiliary storage device 204 is a high-capacity, non-volatile storage device such as a magnetic storage device (HDD (Hard Disk Drive)) or flash memory (SSD (Solid State Drive)), and stores data used by the processor (CPU) 201 when executing programs and programs executed by the processor (CPU) 201. In other words, programs are read from the auxiliary storage device 204, loaded into memory 202, and executed by the processor (CPU) 201, thereby realizing the various functions of the communication control device 102.

[0028] Communication interface (I / F) 205 is a network interface device that controls communication with other devices according to a predetermined protocol.

[0029] The input interface (I / F) 203 is an interface to which input devices 207, such as a keyboard or mouse, are connected, and to receive input from the operator.

[0030] The output interface (I / F) 206 is an interface to which an output device 208, such as a display device, is connected, and which outputs the program execution results in a format that can be viewed by the operator.

[0031] The program executed by the processor (CPU) 201 is provided to the communication control device 102 via removable media (e.g., CD (Compact Disk)-ROM, flash memory, etc.) and stored in a non-volatile auxiliary storage device 204, which is a non-temporary storage medium. For this reason, the communication control device 102 should have an interface for reading data from the removable media.

[0032] Furthermore, the communication management device 103 has the same configuration and functions as the communication control device 102 described above, so a detailed explanation will be omitted.

[0033] Figure 3 shows an example of the device status display screen 301 displayed on the output device 208 of the communication management device 103. The device status display screen 301 of the communication management device 103 consists of device status information 302 for the ground environment devices, application device 101-1 and communication control device 102-1; status information 303 for the wireless network 106; status information 304 for the on-board environment devices, wireless terminal 107, communication control device 102-2, and application device 101-2; a ground environment detailed display button 305 for displaying detailed information about the ground environment devices; a wireless environment detailed display button 306 for displaying detailed information about the wireless environment; and an on-board environment detailed display button 307 for displaying detailed information about the on-board environment devices.

[0034] For detailed information and settings regarding communication control in the communication control device 102, the ground-side communication control device 102-1 displays a screen for executing processes using the ground environment details display button 305, and the on-board communication control device 102-2 displays a screen for executing processes using the on-board environment details display button 307. Examples of the setting screens for the ground-side communication control device 102-1 and the on-board communication control device 102-2 on the communication management device screen will be described later with reference to Figure 4.

[0035] Figure 4 shows an example of the on-board communication environment setting screen 401 displayed on the output device 208 of the communication management device 103. The on-board communication environment settings screen 401 consists of the settings screen 402-1 for communication control device A102-2-1, the settings screen 402-2 for communication control device B102-2-2, the settings screen 402-3 for wireless terminal A107-1, the settings screen 402-4 for wireless terminal B107-2, and the settings screen 402-5 for application device 101-2.

[0036] The settings screen 402-1 of the communication control device A102-2-1 displays device status information 403 acquired from the communication control device A102-2-1, device operating status information 404, information on the number of applications to be controlled 405, and a list of detailed information related to communication control 407. To change the operating state of the communication control device A102-2-1, change the operating state information 404 displayed on the screen to the desired state, and then execute the process using the setting button 406.

[0037] The detailed information list 407 regarding communication control includes transmission application information 408, transfer status information 409 indicating whether the communication control device will perform communication control of the data received from the application device, and destination wireless terminal information 410 which specifies and displays the destination wireless terminal.

[0038] The transmission application information 408 displays the application type, the amount of transmission traffic requested by the application, and the transfer priority information. The transfer priority information is used to determine whether or not to implement path redundancy control even in the standby system, and the priority is displayed according to a predefined rule.

[0039] To change whether a specific application can transmit data using the communication control device 102, the transfer status information 409 and destination wireless terminal information 410 are changed, and then the process is executed using the setting button 411. For all of the multiplexed communication control devices 102 that constitute the railway communication system, it is possible to set whether or not to transmit data based on rules linked to transfer priority information, or from a detailed list of information 407 regarding communication control of the communication management device 103, and thereby change the communication control of the communication control devices 102.

[0040] Figure 5 is a block diagram showing an example of the configuration of the communication control device 102 according to the present invention. The communication control device 102 includes an application data transmission device 501 and an application data reception device 502.

[0041] The application data transmission device 501 uses the status information of the multiplexed communication control device 102 on the transmitting side to appropriately select and transmit the application data received from the application device 101 on the transmitting side to the wireless terminal 107 which will serve as the communication channel.

[0042] The application data receiving device 502 receives application data transmitted from the application data transmitting device 501 of the transmitting communication control device 102 and transmits only the appropriate data to the receiving application device 101. [Examples]

[0043] Figure 6 is a block diagram showing an example of the configuration of the application data transmission device 501 according to Embodiment 1. The application data transmission device 501 includes an external communication control device status acquisition unit 603, an internal communication control device status acquisition unit 604, a data transfer determination unit 605, and a transmission control unit 606.

[0044] The other communication control device status acquisition unit 603 takes the other communication control device status information 602 as input and outputs information that allows the data transfer determination unit 605 to determine whether or not to transfer the application data received from the transmitting application device 101. Here, the other communication control device status information 602 refers to information indicating the operating status of the transmitting communication control device 102 on which the communication control device 102 is installed. For example, it indicates whether or not it is the active system, whether both the hardware and software are operating normally, the transfer status for application data, and information about the destination wireless terminal.

[0045] The self-communication control device status acquisition unit 604 acquires the self-communication control device status information from the transmitting communication control device 102 and the communication results of application data from the wireless terminal 107 from the transmission control unit 606, and outputs this information to the data transfer determination unit 605 and the transmission control unit 606 as appropriate. Here, the self-communication control device status information refers to information indicating the operating status of the self-communication control device 102. For example, it indicates whether it is in active use or not, whether both the hardware and software are functioning normally, information about the destination wireless terminal, the identification number of the destination communication control device, etc.

[0046] The data transfer determination unit 605 takes the self-communication control device transmission application information 601, the output information of the other communication control device status acquisition unit 603, and the output information of the self-communication control device status acquisition unit 604 as input to determine the transfer status of application data in the communication control device 102, and outputs the determination result to the transmission control unit 606. Here, the decision result can be any information that allows the transmission control unit 606 to decide whether or not to transfer application data. For example, it could be flag information or information for switching from the standby system to the active system.

[0047] Furthermore, the communication control device transmission application information 601 includes at least the amount of communication traffic of the application to be transmitted, identification information of the wireless terminal used as the communication channel, information on whether data transfer processing is possible, and priority information for when the standby communication control device switches to the active system. Some of this information is common with the information stored in the transmission application information DB1402 (Figure 15) used in Embodiment 2, which will be described later.

[0048] The transmission control unit 606 performs the following processes based on the determination result of the data transfer determination unit 605: transferring application data received from the transmitting application device 101; outputting the result of the data transfer to the self-communication control device status acquisition unit 604; and transmitting the self-communication control device status information acquired by the self-communication control device status acquisition unit 604 as other communication control device status information 602 to the other communication control device 102 or the communication management device 103. Furthermore, the source of the data output for the self-communication control device transmission application information 601 and the other communication control device status information 602, which are input to the application data transmission device 501, is not limited.

[0049] Figure 7 is a flowchart illustrating an example of the processing procedure of the other communication control device status acquisition unit 603 of the application data transmission device 501 according to Embodiment 1. The operation of each processing step will be described below, but since the main processing unit for each processing step is the other communication control device status acquisition unit 603, the details will be omitted below. Step S701: Obtain other communication control device status information 602 from the device on the system.

[0050] Step S702: Check whether the acquired data of other communication control device status information 602 has been tampered with. This is to address the acquisition of information via the Internet 104. The method for checking whether the data has been tampered with is not particularly limited.

[0051] Step S703: Refer to the verification result from Step S702. If the data has been tampered with (yes), proceed to Step S705; if the data has not been tampered with (no), proceed to Step S704.

[0052] Step S704: Output the transfer permission information for the application in the status information 602 of the other communication control device without editing it.

[0053] Step S705: Edit the transfer permission information for the application in the other communication control device status information 602 to transfer not permitted and output it.

[0054] Figure 8 is a flowchart showing an example of the processing procedure of the self-communication control device state acquisition unit 604 of the application data transmission device 501 according to Embodiment 1. The operation of each processing step will be described below, but since the main processing unit for each processing step is the self-communication control device state acquisition unit 604, the details will be omitted below. Step S801: Obtain hardware status information of the communication control device 102. Here, hardware status information refers to information indicating whether the hardware, as shown in Figure 2, is operating normally. For example, this could include information such as an abnormality in the power supply voltage supplied to the communication control device or an abnormality in CPU usage. The method for obtaining hardware status information is not particularly limited.

[0055] Step S802: Refer to the verification result from step S802. If the verification result indicates a hardware abnormality (yes), proceed to step S808; if the hardware is normal (no), proceed to step S803. Here, if there is one or more verification items for the hardware status information, and at least one of those items is abnormal, the process proceeds to step S808 as an abnormality.

[0056] Step S803: Obtain software status information of the communication control device 102. Here, software status information refers to information indicating the operating status of the program necessary for operation. For example, this includes information such as whether or not there is setting information requested by the communication control device, or whether or not there is error processing in communication control. Note that the method for obtaining software status information is not particularly limited.

[0057] Step S804: Refer to the verification result from step S803. If the verification result shows that there is an abnormality in the software (yes), proceed to step S808; if the software is normal (no), proceed to step S805. Here, if there is one or more verification items in the software status information, and at least one of those items is abnormal, the process proceeds to step S808 as an abnormality.

[0058] Step S805: The transmission control unit 606 obtains information from the wireless terminal 107 connected to the communication control device 102 to determine whether or not communication with the general-purpose wireless system is possible.

[0059] Step S806: Refer to the verification result of step S805. If the verification result shows that communication to the general-purpose wireless system is not possible through the wireless terminal 107 (yes), proceed to step S808. If communication to the general-purpose wireless system is possible through the wireless terminal 107 (no), proceed to step S807.

[0060] Step S807: The communication control device status is set to normal, and the communication control device status information is generated and output.

[0061] Step S808: The communication control device status is considered abnormal, and communication control device status information is generated and output.

[0062] Figure 9 is a flowchart showing an example of the processing procedure of the data transfer determination unit 605 of the application data transmission device 501 according to Embodiment 1. The operation of each processing step will be described below, but since the data transfer determination unit 605 is the main processing unit for each processing step, the details will be omitted below. Step S901: Obtain the output result of the self-communication control device status acquisition unit 604.

[0063] Step S902: The status of the self-communication control device is checked based on the output result of step S901. If the status of the self-communication control device is abnormal (yes), proceed to step S909; if the status of the self-communication control device is normal (no), proceed to step S903.

[0064] Step S903: Obtain the communication control unit's transmission application information 601. Step S904: Based on the information regarding the transfer of the self-communication control device transmission application information 601 acquired in step S903, the operating status of the communication control device 102, such as whether it is the active system or not (based on the output result of the self-communication control device status acquisition unit 604 acquired in step S901), or both of these pieces of information, it is determined whether or not to transfer the application data with the communication control device 102. If transfer is not required (yes), proceed to step S906; if transfer is required (no), proceed to step S905.

[0065] Step S905: Output the transfer permission information for the application data to the transmission control unit 606 as permission. Step S906: Obtain the output result of the other communication control device status acquisition unit 603.

[0066] Step S907: Refer to the information obtained in step S906 and check whether there is another communication control device 102 that grants permission for transfer of application data. If there is another communication control device 102 that grants permission for transfer (yes), proceed to step S909; otherwise (no), i.e., if transfer is necessary, proceed to step S908.

[0067] Step S908: Refer to the information obtained in step S906 and check whether there is another communication control device 102 with a higher priority for transfer processing. If a higher priority communication control device exists (yes), proceed to step S909; otherwise, proceed to step S905.

[0068] Step S909: Output the transfer permission information for the application data to the transmission control unit 606, indicating that it is not permitted.

[0069] Figure 10 is a flowchart showing an example of the processing procedure of the transmission control unit 606 of the application data transmission device 501 according to Embodiment 1. The operation of each processing step will be described below, but since the main processing unit for each processing step is the transmission control unit 606, the details will be omitted below. Note that the processing step (step S901) which is the same as in Figure 9 will not be explained. Step S1001: Obtain the output result of the data transfer determination unit 605.

[0070] Step S1002: Based on the output of step S1001, the system checks the transfer permission information for the application data of the communication control device 102. If the transfer permission information is permitted (yes), the system proceeds to step S1003; otherwise, the system proceeds to step S1004.

[0071] Step S1003: Transmit the application data received from the application device 101. At this time, the communication control method for transmitting the application data is not particularly limited, and the application data is transmitted according to the communication control method set in the communication control device 102, such as continuous transmission control or retransmission control. Here, the receiving communication control device 102 transmits the source identification number (for example, the MAC address or IP address of the communication control device) and the application data itself in order to identify the transmitting communication control device 102. The application data is transmitted based on destination information obtained from the status information of the self-communication control device.

[0072] Step S1004: The communication control device 102 checks for connectivity with all wireless terminals 107 on the communication paths it can use, and outputs the result to the self-communication control device status acquisition unit 604. The method for checking connectivity is not particularly limited.

[0073] Step S1005: The output result of the self-communication control device status acquisition unit 604 is transmitted as other communication control device status information 602 to the other communication control device 102, the communication management device 103, or both, and transfer permission information is also transmitted.

[0074] Figure 11 is a block diagram showing an example of the configuration of the application data receiving device 502 according to Embodiment 1. The application data receiving device 502 includes an external communication control device status acquisition unit 603, an internal communication control device status acquisition unit 604, a transmission data receiving unit 1102, and a reception control unit 1103. Here, the external communication control device status acquisition unit 603 and the internal communication control device status acquisition unit 604 are the same as those in the application data transmitting device 501 shown in Figure 6, so their explanation is omitted.

[0075] The transmitted data receiving unit 1102 takes the transmitted data 1101 as input and outputs information to the receiving control unit 1103 for receiving and transferring data to the receiving application device 101. Here, the transmitted data 1101 is data transmitted from the transmitting communication control device 102, regardless of whether it is the active or standby system, and has the application data body and a source identification number. Furthermore, if the source identification number has changed compared to the immediately preceding transmission data, the source identification number that the self-communication control device state acquisition unit 604 references when generating it in step S807 or step S808 is updated.

[0076] Based on the output of the transmission data receiving unit 1102, the output of the other communication control device status acquisition unit 603, and the output of the own communication control device status acquisition unit 604, the receiving control unit 1103 selects only the information necessary for the receiving application device 101 from the data transmitted from the transmitting communication control device 102, regardless of whether it is the active or standby system, and transfers the data.

[0077] Figure 12 is a flowchart showing an example of the processing procedure of the transmission data receiving unit 1102 of the application data receiving device 502 according to Embodiment 1. The operation of each processing step will be described below, but since the main processing unit for each processing step is the transmission data receiving unit 1102, the details will be omitted below. Note that the processing steps similar to those in Figure 7 (steps S702 and S703) will be omitted from the explanation. Step S1201: Obtain the transmission data 1101 transmitted from the transmitting communication control device 102.

[0078] Step S1202: Output the transmission data to the receiving control unit 1103 without any editing. Step S1203: Discard the transmitted data and do not output it to the receiving control unit 1103.

[0079] Figure 13 is a flowchart showing an example of the processing procedure of the receiving control unit 1103 of the application data receiving device 502 according to Embodiment 1. The operation of each processing step will be described below, but since the receiving control unit 1103 is the main processing unit for each processing step, the details will be omitted below. Note that the processing steps similar to those in Figure 9 (steps S901, S902, and S906) will not be explained. Step S1301: Obtain the output result from the transmitted data receiving unit 1102.

[0080] Step S1302: Check whether there is a communication control device 102 operating in the active system among the multiple communication control devices 102 on the receiving side. If there is a communication control device 102 in the active system (yes), proceed to step S1304; otherwise, proceed to step S1303.

[0081] Step S1303: The transmission data receiving process is performed on the output result of the transmission data receiving unit 1102 acquired in step S1301. Here, as part of the transmission data receiving process, for example, for data that can be identified as having the same data body, only the first data received is received and forwarded to the receiving application device 101, and any data that arrives thereafter is received but discarded. As a result, the application device 101 can receive only the necessary data.

[0082] Step S1304: The transmitted data, which is the output result of the transmitted data receiving unit 1102, is discarded, and the data is not transferred to the receiving application device 101.

[0083] Step S1305: The source identification number of the transmitted data is compared with the source identification number of transmitted data that was previously received and processed. If the source identification number has not changed (no), the processing of the receiving control unit 1103 is terminated; if there has been a change (yes), the process proceeds to step S1306.

[0084] Step S1306: Change the source identification number on the communication control device 102. This allows the destination to be switched instantly even if the active or standby system of the opposing communication control device 102 switches.

[0085] In the above-described embodiment 1, the transfer of application data from the active or standby communication control device 102 to the wireless terminal 107 is permitted based on the other communication control device status information 602 acquired from the other communication control device status acquisition unit 603, the self-communication control device status information acquired from the self-communication control device status acquisition unit 604, and the self-communication control device transmission application information 601 relating to application data transmitted from the application device 101.

[0086] This allows for the pre-selection of communication paths to be used for route redundancy control simultaneously from both the active and standby systems, taking into account the amount of communication traffic transmitted by the application to the wireless terminals 107 that make up the system. As a result, route redundancy control can be implemented that satisfies the requirements of applications that demand immediate switching from the standby system to the active system, such as mission-critical applications, while suppressing the degradation of communication quality caused by transmitting excessive communication traffic to the wireless terminals 107. [Examples]

[0087] Next, Example 2 of the present invention will be described. However, in describing Example 2, we will focus on the differences from Example 1. Also, points that are not specifically mentioned in the following description of Example 2 are the same as in Example 1. Embodiment 2 also assumes a system that communicates data from the application device 101 via a multiplexed communication control device 102 and a general-purpose wireless communication system. However, in Embodiment 2, the application information 601 transmitted by the communication control device is stored in a database (DB) on the application data transmission device 501, and the objective is to realize communication control using that information.

[0088] Figure 14 is a block diagram showing an example of the configuration of the application data transmission device 501 according to Embodiment 2. The application data transmission device 501 includes an external communication control device status acquisition unit 603, an internal communication control device status acquisition unit 604, a data transfer determination unit 605, a transmission control unit 606, a transmission application information acquisition unit 1401, and a transmission application information DB 1402. Note that the same components as those in the application data transmission device 501 according to Embodiment 1 shown in Figure 6 will not be described.

[0089] The transmission application information acquisition unit 1401 receives the transmission application information 601 of the communication control device as input and updates the transmission application information DB 1402 based on that information.

[0090] The transmission application information DB1402 stores information related to the transmission of one or more transmission applications transmitted from the application data transmission device 501, including information to determine whether or not to transfer that application in the standby system.

[0091] Figure 15 shows an example of the data structure stored in the transmission application information DB 1402 of the application data transmission device 501 according to Embodiment 2. The information stored in this transmission application information DB 1402 is the information necessary for processing by the data transfer determination unit 605. The transmission application information DB1402 stores at least the transmission application name, transmission traffic information, wireless terminal information, definition information on whether data transfer processing is permitted, and priority information. Specifically, it is as follows:

[0092] • Transmission application name: Indicates the type of application transmitted from application device 101. • Transmission Traffic Information: Shows the transmission traffic value in bps. • Wireless terminal information: Indicates wireless terminals present on the transmission path. • Definition information for whether data transfer processing is possible: This information indicates whether data transfer processing is possible under normal circumstances, as it is used to determine whether the application data transmission device 501 should transmit the application. • Priority Information: Indicates the priority at which the standby communication control device switches to the active system in the event of a failure in the active system.

[0093] For example, taking the first row of the data configuration 1501 shown in Figure 15 as an example, in the application data transmission device 501 of the communication control device 102, the application named "Application A" is an application that requests "10bps" as transmission traffic information, and is transmitted to the receiving communication control device 102 via two wireless terminals "#1 and #2". Furthermore, "Application A" requires transfer processing even if the communication control device 102 is in standby mode, and switches with "priority: 1" if the active communication control device 102 fails. Note that the application name only needs to be information that identifies the application, and if the application type is uniquely determined by the transmission traffic in the system, it does not need to be registered in the transmission application information DB1402.

[0094] Figure 16 is a flowchart illustrating an example of the processing procedure of the application data transmission device 501 according to Embodiment 2, specifically the application data transmission device 1401. The operation of each processing step will be described below, but since the main processing unit for each step is the application data transmission device 1401, the details will be omitted below. Step S1601: Check whether the communication control device has received the transmission application information 601. If it has not received it (no), the processing of the transmission application information acquisition unit 1401 is terminated. If it has received it (yes), proceed to step S1602.

[0095] Step S1602: The received self-communication control device transmission application information 601 is compared with the information registered in the transmission application information DB 1402. If there is a difference between the received self-communication control device transmission application information 601 and the information registered in DB 1402 (yes), the process proceeds to step S1603; if there is no difference (no), the process proceeds to step S1604.

[0096] Step S1603: Update the information registered in the transmission application information DB1402 using the received self-communication control unit transmission application information 601. Step S1604: Discard the received self-communication control unit transmission application information 601.

[0097] As described above, Embodiment 2 is characterized by achieving the same processing as Embodiment 1 based on the other communication control device status information 602 acquired from the other communication control device status acquisition unit 603, the self-communication control device status information acquired from the self-communication control device status acquisition unit 604, and the transmission application information registered in the transmission application information DB 1402. As a result, it is no longer necessary to acquire the self-communication control device transmission application information 601 each time via the wireless terminal 107, thereby reducing the frequency of deterioration in the communication quality of application data transmitted via the wireless terminal 107 while achieving the same effects as Embodiment 1. [Examples]

[0098] Next, Example 3 of the present invention will be described. However, in describing Example 3, we will focus on the differences from Example 1. Also, points that are not specifically mentioned in the following description of Example 3 are the same as in Example 1. Example 3 envisions communication control aimed at selecting a communication path to use according to the communication status of the communication path and determining whether or not to transfer application data in a communication environment where the amount of communication traffic that a wireless terminal can handle changes depending on the time and location.

[0099] Figure 17 is a block diagram showing an example of the configuration of the application data transmission device 501 according to Embodiment 3. The application data transmission device 501 includes an external communication control device status acquisition unit 603, an internal communication control device status acquisition unit 604, a communication quality evaluation unit 1702, a data transfer determination unit 1703, and a transmission control unit 606. Note that the same components as those in the application data transmission device 501 according to Embodiment 1 shown in Figure 6 will not be described.

[0100] The communication quality evaluation unit 1702 receives the communication quality judgment information 1701 as input, evaluates the communication quality of the communication channel used by the communication control device 102, and outputs the result to the transmission control unit 606.

[0101] The input communication quality judgment information 1701 is information for evaluating communication quality based on communication status information of the communication channel, and is information determined by the communication quality evaluation method. Here, the communication status information of the communication channel includes at least one of the following: communication traffic volume, information on delay until data arrival, or information on the data arrival interval. Furthermore, if, for example, an evaluation model capable of determining deterioration in communication quality based on past communication quality performance is used as a method for evaluating communication quality, that evaluation model becomes the input to the communication quality evaluation unit 1702 as communication quality judgment information 1701. However, the communication quality judgment information 1701 and the method for evaluating communication quality are not limited to the present invention, but the method for evaluating communication quality must be consistent among multiple communication control devices 102.

[0102] The data transfer determination unit 1703 takes the self-communication control device transmission application information 601, the output information of the other communication control device status acquisition unit 603, the output information of the self-communication control device status acquisition unit 604, and the output information of the communication quality evaluation unit 1702 as input to determine the application transfer status in the communication control device 102, and outputs the determination result to the transmission control unit 606.

[0103] Figure 18 is a flowchart showing an example of the processing procedure of the communication quality evaluation unit 1702 of the application data transmission device 501 according to Embodiment 3. The operation of each processing step will be described below, but since the main processing unit for each processing step is the communication quality evaluation unit 1702, the details will be omitted below. Step S1801: Obtain the latest communication quality performance information when selecting wireless terminal 107 on the communication path.

[0104] Step S1802: Obtain communication quality judgment information 1701 that can evaluate the communication quality when a similar wireless terminal 107 on the same communication path was selected in the past.

[0105] Step S1803: Based on the communication quality evaluation method agreed upon among the communication control devices 102, it is determined whether the communication quality is sufficient for selecting a communication path. If the result of the determination is that the communication quality does not satisfy the requirement (no), proceed to step S1805; if the communication quality satisfies the requirement (yes), proceed to step S1804.

[0106] Step S1804: Output information indicating that the wireless terminal 107 can be selected as the communication channel.

[0107] Step S1805: Output information indicating that the wireless terminal 107 cannot be selected as a communication channel.

[0108] Figure 19 is a flowchart showing an example of the processing procedure of the data transfer determination unit 1703 of the application data transmission device 501 according to Embodiment 3. The operation of each processing step will be described below, but since the data transfer determination unit 1703 is the main processing unit for each processing step, the details will be omitted below. The processing steps (steps S901 to S909) which are the same as those in Figure 9 will not be explained, but steps S1901 and S1902 have been added compared to the flowchart shown in Figure 9. Step S1901: Obtain the output result from the communication quality evaluation unit 1702.

[0109] Step S1902: Check whether the wireless terminal 107 can be selected as the communication channel for transmitting application data. If it cannot be selected (yes), proceed to step S909; if it can be selected (no), proceed to step S906.

[0110] In summary, Embodiment 3 is characterized by achieving the same processing as Embodiment 1 based on other communication control device status information 602 acquired from other communication control device status acquisition unit 603, self-communication control device status information acquired from self-communication control device status acquisition unit 604, self-communication control device transmission application information 601, and communication quality evaluation results of the communication channel acquired from communication quality evaluation unit 1702. This makes it possible to automatically reduce the frequency of deterioration in the communication quality of application data transmitted through the wireless terminal 107 in a communication environment where the amount of communication traffic that a wireless terminal can handle changes depending on the time and location, while achieving the same effects as in Example 1. [Examples]

[0111] Next, Example 4 of the present invention will be described. However, in describing Example 4, we will focus on the differences from Example 1. Also, points that are not specifically mentioned in the following description of Example 4 are the same as in Example 1. Example 4 envisions a communication control system in the application data transmission device 501 that, instead of allowing application data transmission in the active system and not allowing it in the standby system, transmits monitoring packets in the standby system to reduce the communication traffic load on wireless terminals, while simultaneously switching to a communication control device that transmits application data immediately in the event of a failure in the active system.

[0112] Figure 20 is a block diagram showing an example of the configuration of the application data transmission device 501 according to Embodiment 4. The application data transmission device 501 includes an external communication control device status acquisition unit 603, an internal communication control device status acquisition unit 604, a monitoring data transmission / reception unit 2001, a data transfer determination unit 2002, and a transmission control unit 606. Note that the same components as those in the application data transmission device 501 according to Embodiment 1 shown in Figure 6 will not be described.

[0113] The monitoring data transmission / reception unit 2001 transmits and receives monitoring data between the transmitting communication control device 102 and the receiving communication control device 102, which are the standby systems, and confirms the status of the communication path from the response of the monitoring data. In Embodiment 4, for example, when a VPN (Virtual Private Network) tunnel is established between the communication control devices 102, the standby system does not transmit data to any communication path, so it cannot maintain the VPN tunnel, and the process of establishing the VPN tunnel occurs, which takes time when switching between the active system and the standby system. Therefore, by using the monitoring data transmission / reception unit 2001 to constantly transmit and receive monitoring data that does not affect the communication quality of application data of the active system's communication control device 102, it is possible to constantly check for abnormalities in the communication path and instantly switch from the standby system to the active system in a system where establishing a communication path takes time.

[0114] Figure 21 is a flowchart showing an example of the processing procedure of the monitoring data transmission / reception unit 2001 of the application data transmission device 501 according to Embodiment 4. The operation of each processing step will be described below, but since the main processing unit for each processing step is the monitoring data transmission / reception unit 2001, the details will be omitted below. Note that the processing step (step S901) which is the same as in Figure 9 will not be explained. Step S2101: Check whether the self-communication control device is the active system or the standby system. If the result of the check is that it is the active system (yes), the processing of the monitoring data transmission / reception unit 2001 is terminated, and if it is the standby system (no), proceed to step S2102.

[0115] Step S2102: The monitoring data is transmitted to the opposing communication control device 102. The monitoring data can be anything that allows the communication path to be confirmed, such as Ping data.

[0116] Step S2103: Check the response to the transmitted monitoring data. If a response is received (yes), proceed to step S2104; if no response is received (no), proceed to step S2105.

[0117] Step S2104: The data transfer determination unit 2002 outputs the result, assuming that the communication channel condition is good.

[0118] Step S2105: The data transfer determination unit 2002 outputs the result indicating that the communication channel condition is poor.

[0119] Figure 22 is a flowchart showing an example of the processing procedure of the data transfer determination unit 2002 of the application data transmission device 501 according to Embodiment 4. The operation of each processing step will be described below, but since the processing main body of each processing step is the data transfer determination unit 2002, the details will be omitted below. Note that the processing steps similar to those in Figures 9 and 21 (steps S901 to S903, steps S905 to S909 and step S2101) will not be explained. Step S2201: Obtain the output result from the monitoring data transmission / reception unit 2001.

[0120] Step S2202: Check whether there are any problems with the communication path status of the destination communication control device 102 based on the output result of the monitoring data transmission / reception unit 2001. If the result of the check is that the communication path status is poor (yes), proceed to step S909; if it is good (no), proceed to step S906.

[0121] As described above, Embodiment 4 is characterized by realizing the same processing as Embodiment 1 based on other communication control device status information 602 acquired from other communication control device status acquisition unit 603, self-communication control device status information acquired from self-communication control device status acquisition unit 604, self-communication control device transmission application information 601, and the monitoring status of the communication path acquired from monitoring data transmission unit 2001. As a result, even in a system where only the active system's communication control device 102 transmits application data, constant monitoring of the communication path using monitoring data reduces the impact on application data transmission in the active system, and allows for instantaneous switching from the standby system to the active system, even in communication systems where establishing a communication path takes time.

[0122] According to the above-described Examples 1 to 4, the present invention encompasses at least the following embodiments. <Aspect 1> A plurality of communication control devices having an active system and a standby system on a communication system that shares a communication channel, comprising: a communication control device status information acquisition unit that acquires self-communication control device status information indicating the device status of its own communication control device and other communication control device status information indicating the device status of other communication control devices; a data transfer determination unit that determines whether or not to transfer first application data received from an application device; a transmission control unit that transmits the first application data based on the transfer feasibility determination result; and a reception control unit that receives second application data transmitted from the transmitting communication control device, wherein the data transfer determination unit determines whether or not to transfer based on the self-communication control device status information, other communication control device status information and information regarding the transmission of the first application data.

[0123] <Aspect 2> The communication control device described in Embodiment 1 above, wherein the other communication control device state information is the communication control device state information of the recipient to which the transmission control unit transmits the first application data, and the communication control device state information of the recipient from which the reception control unit receives the second application data.

[0124] <Aspect 3> A communication control device as described in Embodiment 1 or Embodiment 2 above, wherein the self-communication control device status information includes, at a minimum, the status information of the hardware and software of the self-communication control device, and the status information of wireless terminals connected to the self-communication control device on the communication path.

[0125] <Aspect 4> A communication control device as described in any of the above embodiments 1 to 3, wherein the information relating to the transmission of the first application data includes at least the amount of communication traffic of the first application data, identification information of the wireless terminal used as the communication channel, information on whether data transfer processing is possible, and priority information for switching a standby communication control device to the active system.

[0126] <Aspect 5> A communication control device as described in any of the above embodiments 1 to 4, comprising a database that stores information relating to the transmission of first application data corresponding to one or more applications possessed by the application device.

[0127] <Aspect 6> A communication control device as described in any of the above embodiments 1 to 4, comprising a communication quality evaluation unit that determines whether or not to select a communication channel based on communication status information of the communication channel used by the communication control device, and a data transfer determination unit that determines whether or not to transfer based on the status information of the communication control device itself, the status information of other communication control devices and information regarding the transmission of the first application data, in addition to information regarding whether or not to select the communication channel.

[0128] <Aspect 7> The communication control device described in embodiment 6 above, wherein the communication status information of the communication channel is at least one of the following: the amount of communication traffic, information regarding the delay until data arrival, and information regarding the interval between data arrivals.

[0129] <Aspect 8> A communication control device as described in any of the above embodiments 1 to 4, comprising a monitoring data transmission / reception unit that transmits and receives data to monitor the communication path between standby communication control devices and confirms the status of the communication path, wherein a data transfer determination unit determines whether or not to transfer based on the status information of the communication path in addition to the status information of the communication control device itself, the status information of other communication control devices, and information relating to the transmission of the first application data.

[0130] <Pattern 9> The communication control device described in any of the above embodiments 1 to 8 is applied to the on-board and ground-side devices of a railway communication system connected via a network.

[0131] <Aspect 10> A communication control method using multiple communication control devices having an active system and a standby system on a communication system that shares a communication channel, wherein the device acquires self-communication control device status information indicating the device status of its own communication control device and other communication control device status information indicating the device status of other communication control devices, determines whether or not to transfer the application data based on the self-communication control device status information, other communication control device status information and information on the transmission of application data transmitted between communication control devices, selects a communication channel based on the result of the determination of whether or not to transfer the application data and transmits the application data.

[0132] <Aspect 11> The communication control method described in embodiment 10 above, wherein the communication control device evaluates the communication quality of the communication channel based on the communication status information of the communication channel used by the communication control device to determine whether the communication channel can be selected, and determines whether application data can be transferred based on the status information of the communication control device itself, the status information of other communication control devices, and information regarding the transmission of application data transmitted between communication control devices, in addition to the information regarding whether the communication channel can be selected.

[0133] <Aspect 12> The communication control method described in embodiment 10 above, wherein data is sent and received to monitor the communication path between standby communication control devices, the status of the communication path is checked, and whether or not application data can be transferred is determined based on the status information of the communication control device itself, the status information of other communication control devices, and information regarding the transmission of application data transmitted between communication control devices, in addition to the status information of the communication path.

[0134] <Aspect 13> A communication control method as described in any of embodiments 10 to 12 above, wherein the other communication control device status information is the status information of the communication control device of the recipient to which the application data is to be transmitted, the own communication control device status information is at least the status information of the hardware and software of the own communication control device, and the status information of the wireless terminal connected to the own communication control device on the communication path, and the information relating to the transmission of application data is at least the amount of communication traffic of the application data, identification information of the wireless terminal used as the communication path, information on whether data transfer processing is possible, and priority information for when a standby communication control device switches to the active system.

[0135] <Aspect 14> The communication control program includes instructions that cause the processor to execute the communication control method described in any of the above embodiments 10 to 13.

[0136] As described above, Examples 1 to 4 have been explained as embodiments for carrying out the present invention. However, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the present invention. [Explanation of Symbols]

[0137] 101...Application device, 102...Communication control device, 103...Communication management device, 104...Internet, 105...Core network, 106...Wireless network 107... Wireless terminal, 201... Processor (CPU), 202... Memory 203...Input 1 / F, 204...Auxiliary storage device, 205...Communication I / F 206…Output I / F, 501…Application data transmission device, 502…Application data reception device, 603...Other communication control device status acquisition unit, 604...Own communication control device status acquisition unit, 605, 1703, 2002... Data transfer determination unit, 606... Transmission control unit, 1102...Transmission data receiving unit, 1103...Receiving control unit, 1401...Transmission application information acquisition unit, 1402...Transmission application information DB, 1702...Communication Quality Evaluation Department, 2001...Monitoring Data Transmission and Reception Department

Claims

1. Multiple communication control devices having an active system and a standby system on a communication system that shares a communication channel, A communication control device status information acquisition unit acquires self-communication control device status information indicating the device status of its own communication control device and other communication control device status information indicating the device status of other communication control devices. A data transfer determination unit that determines whether or not to transfer the first application data received from the application device, A transmission control unit that transmits the first application data based on the result of the determination of whether or not the transfer is possible, A receiving control unit that receives second application data transmitted from the transmitting communication control unit, Equipped with, The data transfer determination unit determines whether the transfer is permissible based on the state information of its own communication control device, the state information of other communication control devices, and information regarding the transmission of the first application data. A communication control device characterized by the following:

2. A communication control device according to claim 1, The aforementioned other communication control device status information is the status information of the communication control device of the recipient to which the transmission control unit transmits the first application data, and the status information of the communication control device of the recipient from which the reception control unit receives the second application data. A communication control device characterized by the following:

3. A communication control device according to claim 1, The aforementioned communication control device status information includes, at a minimum, the status information of the hardware and software of the communication control device itself, and the status information of wireless terminals connected to the communication control device on the communication path. A communication control device characterized by the following:

4. A communication control device according to claim 1, The information relating to the transmission of the first application data includes, at a minimum, the amount of communication traffic for the first application data, identification information of the wireless terminal used as the communication channel, information on whether data transfer processing is possible, and priority information for when the standby communication control device switches to the active system. A communication control device characterized by the following:

5. A communication control device according to any one of claims 1 to 4, The system includes a database that stores information relating to the transmission of the first application data, corresponding to one or more applications possessed by the application device. A communication control device characterized by the following:

6. A communication control device according to any one of claims 1 to 4, The communication control device includes a communication quality evaluation unit that determines whether or not to select a communication channel based on the communication status information of the communication channel used by the communication control device, The data transfer determination unit determines whether the transfer is permitted or not based on the status information of its own communication control device, the status information of other communication control devices, and information regarding the transmission of the first application data, in addition to information regarding the selection of the communication path. A communication control device characterized by the following:

7. A communication control device according to claim 6, The communication status information of the aforementioned communication channel includes at least one of the following: the amount of communication traffic, information regarding the delay until data arrival, and information regarding the interval between data arrivals. A communication control device characterized by the following:

8. A communication control device according to any one of claims 1 to 4, It includes a monitoring data transmission / reception unit that sends and receives data to monitor the communication path between standby communication control devices and confirms the status of said communication path. The data transfer determination unit determines whether the transfer is permitted or not based on the state information of the communication control device itself, the state information of other communication control devices, and the information relating to the transmission of the first application data, in addition to the state information of the communication channel. A communication control device characterized by the following:

9. A communication system to which the communication control device described in any one of claims 1 to 4 is applied to the on-board equipment and ground-side equipment of a railway communication system connected via a network.

10. A communication control method using multiple communication control devices having an active system and a standby system on a communication system that shares a communication channel, It acquires its own communication control device status information, which indicates the device status of its own communication control device, and other communication control device status information, which indicates the device status of other communication control devices. Based on the state information of the self-communication control device, the state information of the other communication control device, and the information regarding the transmission of application data transmitted between the communication control devices, a determination is made as to whether or not the application data can be transferred. Based on the determination of whether or not the aforementioned application data can be transferred, a communication channel is selected and the application data is transmitted. A communication control method characterized by the following:

11. A communication control method according to claim 10, Based on the communication status information of the communication channel used by the aforementioned communication control device, the communication quality of the communication channel is evaluated to determine whether or not the communication channel can be selected. Whether or not the aforementioned application data can be transferred is determined based on the status information of the self-communication control device, the status information of other communication control devices, and information regarding the transmission of application data transmitted between the communication control devices, in addition to information regarding the selection of the communication path. A communication control method characterized by the following:

12. A communication control method according to claim 10, It sends and receives data to monitor the communication path between standby communication control devices and checks the status of the said communication path. Whether or not the aforementioned application data can be transferred is determined based on the status information of the communication control device itself, the status information of other communication control devices, and information regarding the transmission of application data transmitted between the communication control devices, in addition to the status information of the communication channel. A communication control method characterized by the following:

13. A communication control method according to any one of claims 10 to 12, The aforementioned other communication control device status information is the communication control device status information of the recipient to whom the application data is transmitted. The aforementioned communication control device status information includes, at a minimum, the status information of the hardware and software of the communication control device itself, and the status information of wireless terminals connected to the communication control device on the communication path. The information relating to the transmission of the application data includes, at a minimum, the amount of communication traffic for the application data, identification information of the wireless terminal used as the communication channel, information on whether data transfer processing is possible, and priority information for when the standby communication control device switches to the active system. A communication control method characterized by the following:

14. A communication control program having an instruction to cause a processor to execute the communication control method described in any one of claims 10 to 13.

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