Communication control device, communication control method, communication control program, and communication control system

Abstract

To easily make a communication network redundant.SOLUTION: A communication control device 51 of an embodiment includes a first wired communication unit 511, a second wired communication unit 512, a wireless communication unit 513, an identifying unit 5151, and a communication control unit 5152. The first wired communication unit 511 has a wired communication function. The second wired communication unit 512 has a wired communication function and is connected to an IO node 21. The wireless communication unit 513 has a wireless communication function. The identifying unit 5151 is connected to the first wired communication unit 511 via a wired network and identifies another communication control device that satisfies a condition. The communication control unit 5152 establishes communication with the other communication control device via a wireless network.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a communication control device, a communication control method, a communication control program, and a communication control system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in order to provide redundancy to a communication network having a plurality of nodes, a method is known in which each node is connected to a plurality of paths by wires (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-112977 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional techniques have a problem in that redundancy in a communication network may not be easily achieved.

[0005] For example, in conventional technology, each node needs to be provided with the same number of physical communication ports as the number of paths to be connected. However, it may be difficult to provide multiple communication ports due to reasons such as miniaturization of nodes.

[0006] A conventional communication control system will be described with reference to Fig. 8. Fig. 8 is a diagram showing a conventional communication control system.

[0007] 8, the communication control system 1a includes a switch 11, an IO node 21a, a calculation node 22a, and a terminal 31. The IO node 21a is connected to a field device 41 and a field device .

[0008] Here, a node is a device that processes information and performs communication. A node may also be referred to as a computer or the like.

[0009] The IO node 21a includes a wired communication unit 211 and a wired communication unit 212a. The wired communication unit 211 is connected to the switch 11, and the wired communication unit 212a is connected to the switch 12. The calculation node 22a includes a wired communication unit 221 and a wired communication unit 222a. The wired communication unit 221 is connected to the switch 11, and the wired communication unit 222a is connected to the switch 12. The terminal 31 includes a wired communication unit 311. The wired communication unit 311 is connected to the switch 11.

[0010] In this way, the communication control system 1a has a network configuration in which redundancy is provided between the IO node 21a and the calculation node 22a by a star (or mesh) topology. However, as described above, if a node cannot be provided with multiple communication ports, the network configuration shown in FIG. 8 cannot be realized.

[0011] One object of the present invention is to easily realize redundancy in a communication network. [Means for solving the problem]

[0012] A communication control device according to one aspect is characterized in that it has a first wired communication unit having a wired communication function, a second wired communication unit having a wired connection function and connected to a node, a wireless communication unit having a wireless communication function, an identification unit connected to the first wired communication unit via a wired network and identifying other communication control devices that satisfy a condition, and a communication control unit that establishes communication via the wireless network with the other communication control devices.

[0013] A communication control method according to one aspect is a communication control method executed by a communication control device having a first wired communication unit having a wired communication function, a second wired communication unit having a wired communication function and connected to a node, and a wireless communication unit having a wireless communication function, and is characterized in including an identification process for identifying other communication control devices that are connected to the first wired communication unit via a wired network and satisfy a condition, and a communication control process for establishing communication via a wireless network between the other communication control devices.

[0014] A communication control program according to one aspect is characterized in that it causes a communication control device having a first wired communication unit having a wired communication function, a second wired communication unit having a wired communication function and connected to a node, and a wireless communication unit having a wireless communication function to execute a process of identifying other communication control devices that are connected to the first wired communication unit via a wired network and satisfy a condition, and establishing communication via the wireless network with the other communication control devices.

[0015] According to one aspect, a communication control system includes a first node, a first communication control device, a second node, and a second communication control device, wherein the first communication control device includes a first wired communication unit having a wired communication function, a second wired communication unit having a wired communication function and connected to the first node, and a first wireless communication unit having a wireless communication function, and when the first wired communication unit is connected to the second communication control device via a wired network, the first communication control device establishes communication with the second communication control device via a wireless network, and transmits a frame transmitted from the first node to the second node via both the wired network and the wireless network. and a first communication control unit that transmits frames to the second communication control device, the second communication control device having a third wired communication unit having a wired communication function, a fourth wired communication unit having a wired communication function and connected to the second node, a second wireless communication unit having a wireless communication function, and a second communication control unit that, when the third wired communication unit is connected to the first communication control device via the wired network, establishes communication via the wireless network with the first communication control device and transmits frames to be transmitted from the second node to the first node to the first communication control device via both the wired network and the wireless network. Effect of the Invention

[0016] According to one embodiment, redundancy in a communication network can be easily achieved. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram illustrating an example of the configuration of a communication control system according to a first embodiment. [Diagram 2] 1 is a diagram illustrating an example of the configuration of a communication control system according to a first embodiment. [Diagram 3] 1 is a diagram illustrating an example of the configuration of a communication control system according to a first embodiment. [Figure 4] 1 is a diagram illustrating an example of the configuration of a communication control device according to a first embodiment; [Diagram 5] 4 is a flowchart showing a process flow of the communication control device. [Figure 6] 4 is a flowchart showing a process flow of the communication control device. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration. [Figure 8] FIG. 1 illustrates a conventional communication control system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the communication control device, communication control method, communication control program, and communication control system disclosed in the present application will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described here. Also, the same elements are given the same reference numerals, and duplicated descriptions are omitted as appropriate. Also, each embodiment can be appropriately combined within a range that does not cause contradictions.

[0019] The configuration of the communication control system according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of the communication control system according to the first embodiment.

[0020] 1, the communication control system 1 includes a switch 11, an IO node 21, a calculation node 22, a terminal 31, a communication control device 51, and a communication control device 52. The IO node 21 is connected to a field device 41 and a field device 42.

[0021] Here, a node is a device that processes information and communicates. A node may also be called a computer, etc. A field device transmits a sensor value detected by a sensor or a frame indicating a detection result based on the sensor value to the node using a predetermined communication protocol.

[0022] For example, the field device 41 and the field device 42 are provided in a plant. The plant is, for example, an oil plant, a petrochemical plant, a chemical plant, or a gas plant. When the plant is operated, products such as LNG (liquefied natural gas), resins (plastic, nylon, etc.), and chemical products are obtained.

[0023] The plant also includes factory facilities, machine facilities, production facilities, power generation facilities, storage facilities, wellhead facilities for extracting oil, natural gas, etc. The plant also includes equipment for producing products.

[0024] The field device 41 acquires information about the state of the plant. For example, the field device 41 is a temperature sensor, a pH sensor, a speed sensor, an acceleration sensor, an air pressure sensor, a gas concentration sensor, a device that detects the opening degree of a valve, a device that detects the state (on or off) of a switch, etc. The field device 42 is an actuator that drives a valve or the like.

[0025] In addition, the IO node 21 transmits the frame acquired from the field device 41 to the calculation node 22. The calculation node 22 performs calculation processing. In addition, the calculation node 22 transmits the result of the calculation processing (control signal, etc.) to the field device 41, the field device 42, etc. via the IO node 21.

[0026] The configuration and operation of the nodes included in the communication control system 1 are not limited to those described here. The nodes included in the communication control system 1 may be any nodes that communicate data with each other.

[0027] The IO node 21 includes a wired communication unit 211. The wired communication unit 211 is connected to a communication control device 51. The calculation node 22 includes a wired communication unit 221. The wired communication unit 221 is connected to a communication control device 52. The terminal 31 includes a wired communication unit 311. The wired communication unit 311 is connected to the switch 11. In addition,

[0028] In this way, each of the IO node 21 and the computing node 22 is assumed to have one wired communication unit. Each of the wired communication units may include, for example, an Ethernet port to which a LAN (Local Area Network) cable is connected.

[0029] Here, the terminal 31 is a device such as a PC (Personal Computer) for managing the switch 11. Here, the terminal 31 is a device such as an HMI (Human Machine Interface) for operating and monitoring various nodes, or a PC (Personal Computer) for network management, etc. Although the terminal 31 in Fig. 1 has only one wired communication unit, it is possible to easily add more wired communication units as necessary.

[0030] On the other hand, since the nodes are installed in narrow places or places where the available space is limited, there are constraints such as miniaturization, weight reduction, and simple configuration, etc. For this reason, it is preferable that the number of communication ports of the node is small.

[0031] According to the communication control device 51 and the communication control device 52 of this embodiment, even if a node has only one communication port, a redundant network configuration can be easily realized between the nodes, at least between the communication control device 51 and the communication control device 52.

[0032] The communication control device 51 has a first wired communication unit 511, a second wired communication unit 512, and a wireless communication unit 513. The first wired communication unit 511 is connected to the switch 11. The second wired communication unit 512 is connected to the wired communication unit 211 of the IO node 21.

[0033] The communication control device 52 also includes a third wired communication unit 521, a fourth wired communication unit 522, and a wireless communication unit 523. The third wired communication unit 521 is connected to the switch 11. The fourth wired communication unit 522 is connected to the wired communication unit 221 of the calculation node 22.

[0034] Each wired communication unit is, for example, a wired communication module. The wired communication module is a module having a communication function corresponding to a predetermined wired communication protocol, such as an Ethernet module, a Fibre Channel module, a USB module, etc. The wireless communication unit is a wireless communication module. The wireless communication module is a module having a communication function corresponding to a predetermined wireless communication protocol, such as a WiFi (registered trademark) module, a Bluetooth (registered trademark) module, an LPWA (Low Power Wide Area) module, etc.

[0035] The nodes and the communication control unit may be connected by USB (Universal Serial Bus) instead of Ethernet. In this case, the wired communication unit 211, the second wired communication unit 512, the wired communication unit 221, and the fourth wired communication unit 522 each have a USB port. The communication control device 51 can receive power from the IO node 21 via the USB port.

[0036] The following describes the operations of the communication control device 51 and the communication control device 52. Since the communication control device 51 and the communication control device 52 have the same functions, the communication control device 51 and the communication control device 52 in the following description may be appropriately replaced.

[0037] 1, the communication control device 51 is connected to the switch 11 and the IO node 21 via a wired network. The communication control device 52 is connected to the calculation node 22 via a wired network. The communication control device 51 and the communication control device 52 are connected to the wired network including the switch 11. Note that communication control devices other than the communication control device 51 and the communication control device 52, other nodes, and other terminals may be further connected to the wired network.

[0038] When the first wired communication unit 511 is connected to a wired network, the communication control device 51 identifies another communication control device that is connected to the wired network and satisfies a condition. For example, the communication control device 51 identifies another communication control device identified by predetermined identification information. It is assumed that the communication control device 52 satisfies the condition. Furthermore, the communication control device 51 discovering a communication control device by identification may be rephrased as identifying a communication device.

[0039] The identification information is, for example, a MAC address. For example, the communication control device 51 stores the MAC address. Then, the communication control device 51 identifies the communication control device 52 having the stored MAC address.

[0040] Furthermore, it is assumed that the communication control device 52 identifies the communication control device 51 as another communication control device that satisfies the conditions by the same method as the communication control device 51. At this time, the communication control device 51 and the communication control device 52 have identified each other as communication control devices that satisfy the conditions, and communication is established between the wireless communication unit 513 and the wireless communication unit 523 via the wireless network.

[0041] For example, the communication control device 51 establishes communication with the communication control device 52 by performing Bluetooth pairing. Also, for example, the communication control device 51 establishes communication with the communication control device 52 by making itself a WiFi access point or through a peer-to-peer connection.

[0042] 2, the communication control device 51 and the communication control device 52 are connected by both a wired network (solid line in FIG. 2) and a wireless network (dotted line in FIG. 2). That is, a redundant network configuration is easily realized at least between the communication control device 51 and the communication control device 52.

[0043] Furthermore, the communication control device 52 transmits a frame sent from the computation node 22 to the IO node 21 via both the route via the wired network and the route via the wireless network. When the communication control device 51 receives the same frame from the communication control device 52 via both the wired network and the wireless network, it transfers the frame that was received first to the IO node 21 and discards the frame that was received later. This eliminates the need for time-consuming processing such as retransmission of the frame or switching from the abnormal network to the normal network, even if one of the frames does not arrive correctly.

[0044] The forwarding and discarding of frames by the communication control system 1 may be achieved using a method such as IEEE 802.1CB (Frame Replication and Elimination for Reliability).

[0045] Furthermore, as shown in Fig. 3, consider a case where the switch 11 becomes unavailable due to a failure. In this case, the communication control device 51 cannot communicate with the communication control device 52 using the wired network. On the other hand, if communication via a wireless network has been established, the communication control device 51 can continue to communicate with the communication control device 52 using the wireless network. The communication control system 1 can enjoy the merits of such redundancy. For example, if the switch 11 fails, the terminal 31 is cut off from the network. Even in such a case, wireless communication between the communication control device 51 and the communication control device 52 can continue to be available.

[0046] The configuration of the communication control device 51 will be described with reference to Fig. 4. This is a diagram showing an example of the configuration of a communication control device according to the first embodiment. Note that the configuration of the communication control device 52 is the same as that of the communication control device 51.

[0047] As shown in FIG. 4, the communication control device 51 includes a first wired communication unit 511, a second wired communication unit 512, a wireless communication unit 513, a storage unit 514, and a control unit 515.

[0048] The first wired communication unit 511 has a wired communication function. The second wired communication unit 512 has a wired communication function and is connected to the IO node 21. The wireless communication unit 513 has a wireless communication function.

[0049] The storage unit 514 stores various data and various programs executed by the control unit 515. For example, the storage unit 514 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), a flash memory, etc. The storage unit 514 stores various data generated in the processing executed by the communication control device 51 as necessary, such as data obtained in the process of executing various processes by the control unit 515 and processing results obtained by executing various processes.

[0050] The control unit 515 is a processing unit that controls the entire communication control device 51. The control unit 515 is an arithmetic unit such as a CPU (Central Processing Unit) having a processor, a microcomputer, etc. The control unit 515 has a specification unit 5151 and a communication control unit 5152.

[0051] When the first wired communication unit 511 is connected to a wired network, the identifying unit 5151 identifies another communication control device that is connected to the wired network and satisfies a condition. For example, the identifying unit 5151 identifies another communication control device identified by predetermined identification information.

[0052] The communication control unit 5152 establishes communication with other communication control devices via a wireless network. When the communication control unit 5152 receives the same frame from other communication control devices via both the wired network and the wireless network, the communication control unit 5152 transfers the frame that was received first to the IO node 21 and discards the frame that was received later.

[0053] The process of establishing a wireless network by the communication control device will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the flow of the process by the communication control device.

[0054] 5, first, the communication control device 51 waits (step S101) until a trigger occurs in a state where the communication control device 51 is connected to a wired network (step S101, No). The trigger may be a connection to a wired network, a certain time has elapsed since the connection to the wired network, or a manual operation.

[0055] When a trigger occurs (Yes at step S101), the communication control device 51 identifies a communication control device that satisfies a condition in the wired network (step S102).

[0056] If there is no communication control device that satisfies the condition (step S103, No), the communication control device 51 ends the process. Also, the communication control device 51 may reset the trigger and return to the start. On the other hand, if there is a communication control device that satisfies the condition (step S103, Yes), the communication control device 51 establishes a wireless network with the communication control device that satisfies the condition (step S104).

[0057] The process of forwarding a frame by the communication control device will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the flow of the process by the communication control device.

[0058] As shown in FIG. 6, first, the communication control device 51 receives a frame from either a wired network or a wireless network (step S201).

[0059] If the computation node 22 connected to the communication control device 52 that established the wireless network is the frame source (step S202, Yes), the communication control device 51 proceeds to step S203. If not (step S202, No), the communication control device 51 transfers the received frame to the IO node 21 (step S206) and ends the process.

[0060] If the information identifying the received frame is stored in the storage unit 514 (step S203, Yes), the communication control device 51 deletes the stored information and discards the received frame (step S204). On the other hand, if the information identifying the received frame is not stored in the storage unit 514 (step S203, No), the communication control device 51 stores the information identifying the received frame in the storage unit 514 and transfers the received frame to the IO node 21 (step S205). The information identifying the frame is, for example, a hash value calculated from the entire frame or a sequence number intentionally inserted into the frame by the communication control device 52, and when the information intentionally inserted into the frame is used, the information is the entire frame removed from the frame before the frame is transferred, the sequence number intentionally inserted into the frame, etc.

[0061] Discarding a frame may mean not forwarding the received frame, may mean not storing the received frame in memory, or may mean actively deleting the received frame.

[0062] As described above, the first wired communication unit 511 has a wired communication function. The second wired communication unit 512 has a wired communication function and is connected to the IO node 21. The wireless communication unit 513 has a wireless communication function. When the first wired communication unit 511 is connected to a wired network, the identification unit 5151 identifies other communication control devices that are connected to the wired network and satisfy a condition. The communication control unit 5152 establishes communication with the other communication control devices via a wireless network. This makes it possible to easily achieve redundancy in the main path of the communication network even if each node has only one communication port.

[0063] Furthermore, the identifying unit 5151 identifies other communication control devices identified by predetermined identification information, thereby enabling the communication control device 51 to reliably identify communication control devices that satisfy the conditions.

[0064] Furthermore, when the communication control unit 5152 receives the same frame from other communication control devices via both the wired network and the wireless network, it transfers the frame that was received earlier to the IO node 21 and discards the frame that was received later. As a result, even if one of the frames does not arrive correctly, the communication control unit 5152 does not need to resend the frame or perform time-consuming processing such as switching from an abnormal network to a normal network, thereby achieving stable operation of communication.

[0065] [system] The information including the processing procedures, control procedures, specific names, various frames and parameters shown in the above documents and drawings can be changed arbitrarily unless otherwise specified.

[0066] In addition, each component of each device shown in the figure is a functional concept, and does not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure. In other words, all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

[0067] Furthermore, each processing function performed by each device may be realized, in whole or in part, by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware using wired logic.

[0068] [Hardware] Next, a description will be given of an example of the hardware configuration of the communication control device 51. Fig. 7 is a diagram for explaining an example of the hardware configuration. The communication control device 51 and the communication control device 52 have the same hardware configuration as the communication control device 500 in Fig. 7.

[0069] 7, the communication control device 500 includes a communication device 500a, a HDD 500b, a memory 500c, and a processor 500d. The components shown in FIG. 7 are connected to each other via a bus or the like.

[0070] The communication device 500a is a network interface card or the like, and communicates with external devices and equipment. The HDD 500b stores programs and data for operating the functions shown in FIG.

[0071] The processor 500d reads out a program that executes the same processes as the respective processing units shown in FIG. 4 from the HDD 500b or the like and loads it in the memory 500c, thereby operating a process that executes the respective functions described in FIG. 4 or the like. For example, this process executes the same functions as the respective processing units of the communication control device 51. Specifically, the processor 500d reads out a program having the same functions as the identification unit 5151 and the communication control unit 5152 from the HDD 500b or the like. Then, the processor 500d executes a process that executes the same processes as the identification unit 5151 and the communication control unit 5152.

[0072] In this way, the communication control device 51 operates as a communication control device that executes a communication control method by reading and executing a program. The communication control device 51 can also realize functions similar to those of the above-mentioned embodiment by reading the program from a recording medium using a medium reading device and executing the read program. Note that the program in these other embodiments is not limited to being executed by the communication control device 51. For example, the present invention can be similarly applied to cases where another computer or server executes a program, or where these cooperate to execute a program.

[0073] This program can be distributed via a network such as the Internet. This program can also be recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, a magneto-optical disk (MO), or a digital versatile disk (DVD), and can be executed by being read out from the recording medium by a computer.

[0074] Some examples of combinations of the disclosed technical features are set out below.

[0075] (1) a first wired communication unit having a wired connection function; a second wired communication unit having a wired connection function and connected to the node; A wireless communication unit having a wireless communication function; an identifying unit that is connected to the first wired communication unit via a wired network and identifies another communication control device that satisfies a condition; a communication control unit that establishes communication with the other communication control device via a wireless network; A communication control device comprising: (2) The identification unit identifies another communication control device identified by predetermined identification information. The communication control device according to (1) above. (3) The identification unit identifies another communication control device identified by a predetermined MAC address. The communication control device according to (1) or (2), (4) When the communication control unit receives the same frame from the other communication control device via both the wired network and the wireless network, the communication control unit transfers the frame that was received first to the node and discards the frame that was received later. The communication control device according to any one of (1) to (3). (5) a first wired communication unit having a wired communication function; a second wired communication unit having a wired communication function and connected to the node; A wireless communication unit having a wireless communication function; A communication control method executed by a communication control device having a step of identifying another communication control device that is connected to the first wired communication unit via a wired network and satisfies a condition; a communication control step of establishing communication with the other communication control device via a wireless network; A communication control method comprising: (6) a first wired communication unit having a wired communication function; a second wired communication unit having a wired communication function and connected to the node; A wireless communication unit having a wireless communication function; A communication control device having Identifying another communication control device that is connected to the first wired communication unit via a wired network and satisfies a condition; Establishing communication with the other communication control device via a wireless network. A communication control program for executing a process. (7) A communication control system having a first node, a first communication control device, a second node, and a second communication control device, The first communication control device includes: a first wired communication unit having a wired communication function; a second wired communication unit having a wired communication function and connected to the first node; A first wireless communication unit having a wireless communication function; a first communication control unit that, when the first wired communication unit is connected to the second communication control device via a wired network, establishes communication with the second communication control device via a wireless network, and transmits a frame transmitted from the first node to the second node to the second communication control device via both the wired network and the wireless network; having The second communication control device includes: a third wired communication unit having a wired communication function; a fourth wired communication unit having a wired communication function and connected to the second node; A second wireless communication unit having a wireless communication function; a second communication control unit that, when the third wired communication unit is connected to the first communication control device via the wired network, establishes communication with the first communication control device via the wireless network, and transmits a frame transmitted from the second node to the first node to the first communication control device via both the wired network and the wireless network; A communication control system comprising: (8) when the first communication control unit receives the same frame from the second communication control device via both the wired network and the wireless network, the first communication control unit transfers the frame that was received earlier to the first node and discards the frame that was received later; When the second communication control unit receives the same frame from the first communication control device via both the wired network and the wireless network, the second communication control unit transfers the frame that was received first to the second node and discards the frame that was received later. The communication control system according to (7) above. [Explanation of symbols]

[0076] 1. Communication Control System 11 Switch 21 IO Nodes 22 Compute Nodes 31 Terminals 41, 42 Field equipment 51, 52 Communication control device 211, 221, 311 Wired Communications Department 511 First Wired Communication Department 512 Second Wired Communication Division 513, 523 Wireless Communication Department 514 Storage section 515 Control Unit 521 Third Wired Communications Division 522 4th Wired Communications Division 5151 Specific part 5152 Communication Control Unit

Claims

1. a first wired communication unit having a wired connection function; a second wired communication unit having a wired connection function and connected to the node; A wireless communication unit having a wireless communication function; an identifying unit that is connected to the first wired communication unit via a wired network and identifies another communication control device that satisfies a condition; a communication control unit that establishes communication with the other communication control device via a wireless network; A communication control device comprising:

2. The identification unit identifies another communication control device identified by predetermined identification information.

2. The communication control device according to claim 1 .

3. The identification unit identifies another communication control device identified by a predetermined MAC address.

2. The communication control device according to claim 1 .

4. When the communication control unit receives the same frame from the other communication control device via both the wired network and the wireless network, the communication control unit transfers the frame that was received first to the node and discards the frame that was received later.

2. The communication control device according to claim 1 .

5. a first wired communication unit having a wired communication function; a second wired communication unit having a wired communication function and connected to the node; A wireless communication unit having a wireless communication function; A communication control method executed by a communication control device having a step of identifying another communication control device that is connected to the first wired communication unit via a wired network and satisfies a condition; a communication control step of establishing communication with the other communication control device via a wireless network; A communication control method comprising:

6. a first wired communication unit having a wired communication function; a second wired communication unit having a wired communication function and connected to the node; A wireless communication unit having a wireless communication function; A communication control device having Identifying another communication control device that is connected to the first wired communication unit via a wired network and satisfies a condition; Establishing communication with the other communication control device via a wireless network. A communication control program for executing a process.

7. A communication control system having a first node, a first communication control device, a second node, and a second communication control device, The first communication control device a first wired communication unit having a wired communication function; a second wired communication unit having a wired communication function and connected to the first node; A first wireless communication unit having a wireless communication function; a first communication control unit that, when the first wired communication unit is connected to the second communication control device via a wired network, establishes communication with the second communication control device via a wireless network, and transmits a frame transmitted from the first node to the second node to the second communication control device via both the wired network and the wireless network; having The second communication control device includes: a third wired communication unit having a wired communication function; a fourth wired communication unit having a wired communication function and connected to the second node; A second wireless communication unit having a wireless communication function; a second communication control unit that, when the third wired communication unit is connected to the first communication control device via the wired network, establishes communication with the first communication control device via the wireless network, and transmits a frame transmitted from the second node to the first node to the first communication control device via both the wired network and the wireless network; A communication control system comprising:

8. when the first communication control unit receives the same frame from the second communication control device via both the wired network and the wireless network, the first communication control unit transfers the frame that was received earlier to the first node and discards the frame that was received later; When the second communication control unit receives the same frame from the first communication control device via both the wired network and the wireless network, the second communication control unit transfers the frame that was received first to the second node and discards the frame that was received later.

8. The communication control system according to claim 7.

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