Communication system

Abstract

To enable reduction of a time required for establishing communication paths in a communication system including multiple relay devices and an SDN controller.SOLUTION: A communication system 100 includes multiple relay devices R1 to R4 and an SDN controller 10. The multiple relay devices R1 to R4 are connected in a ring shape on multiple communication paths for multiple communication devices to communicate with each other. The SDN controller 10 is configured to manage the multiple relay devices R1 to R4. The multiple relay devices R1 to R4 are configured to receive frames transmitted from the SDN controller 10 and to transmit the received frames to the multiple adjacently connected relay devices R1 to R4 among the multiple relay devices R1 to R4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a communication system including a plurality of relay devices and an SDN controller. [Background technology]

[0002] For example, Patent Document 1 below proposes a technique for shortening the time during which communication is interrupted due to congestion occurring on a communication path in the above-mentioned communication system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2016-063285 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of detailed investigation by the inventors, it was found that the technology of the above-mentioned Patent Document 1 does not take into consideration the time required to establish a communication path when a failure occurs in the communication path, etc. In other words, it may take a relatively long time to establish a communication path.

[0005] One aspect of the present disclosure is to enable a reduction in the time required to establish a communication path in a communication system including a plurality of relay devices and an SDN controller. [Means for solving the problem]

[0006] One aspect of the present disclosure is a communication system (100) including a plurality of relay devices (R1, R2, R3, R4) and an SDN controller (10). The plurality of relay devices are connected in a ring shape on a plurality of communication paths for the plurality of communication devices (1, 2) to communicate with each other. The SDN controller is configured to manage the plurality of relay devices.

[0007] At least one of the plurality of relay devices is communicatively connected to the SDN controller. Each of the relay devices R1 to R4 includes a frame receiving unit (26) and a frame transmitting unit (27). The frame receiving unit is configured to receive frames transmitted from the SDN controller. The frame transmitting unit is configured to transmit the received frames to adjacently connected relay devices among the plurality of relay devices.

[0008] With this configuration, a relay device transmits a frame sent from the SDN controller to multiple relay devices connected adjacent to each other, so that the frame can be delivered to all relay devices more quickly than with conventional configurations, thereby further reducing the time required to establish a communication path. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a configuration of a communication system. [Figure 2] 2A shows an example of a destination port change in an embodiment, where FIG. 2A shows a table for relay device R1, FIG. 2B shows a table for relay device R2, FIG. 2C shows a table for relay device R3, and FIG. 2D shows a table for relay device R4. [Figure 3] 3A shows an example of a destination port after change in an embodiment, where FIG. 3A shows a table for relay device R1, FIG. 3B shows a table for relay device R2, FIG. 3C shows a table for relay device R3, and FIG. 3D shows a table for relay device R4. [Figure 4] 4A is a schematic diagram showing an example of a failure recovery procedure, in which FIG. 4A shows that a failure notification is sent to the SDN controller, FIG. 4B shows that communication settings are updated, and FIG. 4C shows that communication is performed via a new communication path. [Figure 5] 5A shows an example of a destination port change in a conventional configuration, where FIG. 5A shows the table of relay device R1, FIG. 5B shows the table of relay device R2, FIG. 5C shows the table of relay device R3, and FIG. 5D shows the table of relay device R4. [Figure 6] 6A shows an example of a destination port after change in a conventional configuration, where FIG. 6A shows the table of relay device R1, FIG. 6B shows the table of relay device R2, FIG. 6C shows the table of relay device R3, and FIG. 6D shows the table of relay device R4. DETAILED DESCRIPTION OF THE INVENTION

[0010] [1. Embodiment] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [1-1.Configuration] The communication system 100 of the embodiment shown in FIG. 1 constitutes an Ethernet (registered trademark) network system mounted on a vehicle such as a passenger car. Note that the network is not limited to Ethernet and may be any network using any communication protocol. The communication protocol may include LIN, CAN (registered trademark), FlexRay (registered trademark), MOST (registered trademark), and CXPI (registered trademark). LIN is an abbreviation for "Local Interconnect Network." CAN is an abbreviation for "Controller Area Network." MOST is an abbreviation for "Media Oriented Systems Transport." CXPI is an abbreviation for "Clock Extension Peripheral Interface."

[0011] 1, the communication system 100 includes a plurality of electronic control devices ECU1 and ECU2 (hereinafter referred to as ECU1-2), an SDN controller 10, and a plurality of relay devices R1, R2, R3, and R4 (hereinafter referred to as R1-R4), which are connected by communication lines.

[0012] ECU is an abbreviation for "Electronic Control Unit," and SDN is an abbreviation for "Software Defined Network." ECU1-2 correspond to communication devices in the present disclosure. The number of ECU1-2 is not limited to two, and three or more may be provided. The number of relay devices R1-R4 is not limited to four, and three or more may be provided. Relay devices R1-R4 may be domain ECUs that control each domain of the vehicle. Relay devices R1-R4 may be zone ECUs that control various ECUs in areas on the front, rear, left, and right sides of the vehicle.

[0013] The ECUs 1 to 2 each include a CPU 31 and a memory 32. The memory 32 stores a program that enables the CPU 31 to execute a predetermined function. The ECUs 1 to 2 are connected to sensors, actuators, and the like (not shown). The ECUs 1 to 2, for example, execute the program in the memory 32 to realize a function of transmitting data (e.g., frames) obtained from sensors to the other ECUs 1 to 2 via the relay devices R1 to R4. Also, for example, the ECUs 1 to 2 realize a function of operating actuators based on data received from the other ECUs 1 to 2 via the relay devices R1 to R4. The ECUs 1 to 2 also have a function of transmitting and receiving data to and from the connected relay devices R1 to R4.

[0014] The SDN controller 10 includes a CPU 11 and a memory 12. The memory 12 stores programs that allow the CPU 11 to execute predetermined functions. By executing the programs in the memory 12, the SDN controller 10 realizes functions possessed by a general SDN controller, such as a function to centrally control network devices such as relay devices R1 to R4 and dynamically change network configuration settings, etc. In other words, the SDN controller 10 is configured to manage multiple relay devices R1 to R4.

[0015] More specifically, the SDN controller 10 sends commands to the relay device R1 and the other multiple relay devices R2 to R4 connected via the relay device R1, causing the relay devices R1 to R4 to set and change the network configuration. The SDN controller 10 has functions as a fault receiving unit 16, a generating unit 17, and a setting notifying unit 18.

[0016] The fault receiving unit 16 is configured to receive link fault notifications from the relay devices R1 to R4. The generating unit 17 is configured to generate new network configuration information based on the link fault information for communication that avoids the faulty link. The setting notifying unit 18 is configured to notify the relay devices R1 to R4 by sending the new network configuration information to them.

[0017] Each of the relay devices R1 to R4 has a function as a gateway device. In its function as a gateway device, it relays communications between ECU1 and ECU2, or communications between the SDN controller 10 and any of the relay devices R1 to R4. It is sufficient that each of the relay devices R1 to R4 has at least a function as a Layer 2 switch. Furthermore, each of the multiple relay devices R1 to R4 is connected in a ring shape on multiple communication paths for ECU1 and ECU2 to communicate with each other.

[0018] The relay devices R1 to R4 communicate to relay frames, which are data conforming to a predetermined standard, particularly frames conforming to the Ethernet standard in this embodiment. To this end, each of the relay devices R1 to R4 is equipped with multiple communication ports (hereinafter referred to as ports) P1 to P4 for transmitting and receiving frames, and a transceiver (not shown) for performing communication processing for relaying conforming to the Ethernet standard. The number of ports is not limited to four, and any number of ports greater than or equal to three can be used.

[0019] Furthermore, the relay device R1 of the multiple relay devices R1 to R4 is directly connected to the SDN controller 10 so as to be able to communicate with the SDN controller 10. That is, the relay device R1 is connected to the SDN controller 10 so as to be able to communicate with the SDN controller 10 without going through multiple communication paths for communication between the ECU1 and the ECU2.

[0020] Each of the relay devices R1 to R4 functions as a microcomputer including a CPU 21 and a memory 22. The memory 22 stores programs for the CPU 21 to execute predetermined functions. The memory 22 also stores rewritable network configuration information (for example, a communication path table, a MAC address table, etc.).

[0021] Each of the relay devices R1 to R4 realizes the functions of the following units by executing a program in the memory 22. That is, the plurality of relay devices R1 to R4 has the functions of a fault detection unit 24, a fault notification unit 25, a frame reception unit 26, and a frame transmission unit 27. The frame transmission unit 27 has the functions of a first transmission unit 28 and a second transmission unit 29.

[0022] The failure detection unit 24 is configured to detect link failures in a plurality of communication paths. The failure notification unit 25 is configured to notify the SDN controller 10 of a link failure when a failure is detected.

[0023] The frame receiving unit 26 is configured to receive frames transmitted from the SDN controller 10. The frame transmitting unit 27 has a function of transmitting frames. A first transmitting unit 28 of the frame transmitting unit 27 is configured to transmit frames received by the frame receiving unit 26 to a plurality of adjacently connected relay devices R2, R3 among the plurality of relay devices R1 to R4. Note that "adjacently connected" indicates that they are connected by only one link, or that the number of hops is one.

[0024] The second transmission unit 29 of the frame transmission unit 27 is configured to, upon receiving a frame addressed to the SDN controller 10, transmit the frame to the plurality of adjacently connected relay devices R1 to R4.

[0025] Each of the ECUs 1 to 2, the SDN controller 10, and the relay devices R1 to R4 may include one microcomputer or multiple microcomputers.

[0026] The method of realizing the functions of each unit included in the ECUs 1-2, the SDN controller 10, and the relay devices R1-R4 is not limited to software, and some or all of the functions may be realized using one or more pieces of hardware. For example, when the functions are realized by electronic circuits that are hardware, the electronic circuits may be realized by digital circuits, analog circuits, or a combination of these.

[0027] In this communication system 100, the SDN controller 10 is connected to port P3 of relay device R1. Port P1 of relay device R1 is also connected to port P2 of relay device R2, and port P1 of relay device R2 is also connected to port P2 of relay device R4. Port P1 of relay device R4 is also connected to port P2 of relay device R3, and port P1 of relay device R3 is also connected to port P2 of relay device R1.

[0028] That is, the relay devices R1 to R4 are connected in a ring shape by connecting each of their ports P1 and P2 to the ports P1 and P2 of the other relay devices R1 to R4. Note that a ring shape also means a loop shape.

[0029] The port P3 of the relay device R3 is connected to the ECU1, and the port P3 of the relay device R4 is connected to the ECU2. That is, among the ports P1 to P4 of the relay devices R1 to R4, the ports P3 and P4 that are not used for the ring connection can be connected to any ECU including the SDN controller 10 and the ECUs 1 and 2 as communication devices.

[0030] For example, if relay device R1 is used as the starting point, there are two communication paths between relay devices R1 to R4: a left-handed (counterclockwise) communication path from relay device R1 to relay device R3, and a right-handed (clockwise) communication path from relay device R1 to relay device R2. Furthermore, if ECU1 is used as the starting point, there are two communication paths between ECU1 and ECU2: a communication path that passes through relay devices R3 and R4 in this order to reach ECU2, and a communication path that passes through relay devices R3, R1, R2, and R4 in this order to reach ECU2.

[0031] That is, the ring-shaped communication path in the communication system 100 can function as two communication paths. Note that the former communication path, which has a smaller number of hops, is usually adopted as the communication path between the ECUs 1 and 2.

[0032] [1-2. Network configuration information] The relay devices R1 to R4 have network configuration information such as that shown in FIGS. 2A to 2D. The network configuration information includes at least a table that associates destination devices of data with destination ports. The destination device is a device to which data is sent, and is identified by a MAC address or the like included in the received data. The destination port is a port used when sending data. Because the destination port is a port used when sending data, it may also be called a transmission port.

[0033] 2A, the network configuration information of the relay device R1 is set so that data addressed to ECU1 is sent from port P2 and data addressed to ECU2 is sent from port P1. Also, it is set so that data addressed to the SDN controller 10 is sent from port P3. Also, it is set so that data addressed to the relay devices R2, R3, and R4 is sent from ports P1 and P2.

[0034] In other words, in the relay device R1, data addressed to the relay devices R2, R3, and R4 is sent from multiple ports, ports P1 and P2, and multiple adjacent relay devices R2 and R3 can receive the data addressed to the relay devices R2, R3, and R4.

[0035] Next, as shown in Fig. 2B, the network configuration information of the relay device R2 is set so that data addressed to ECU1 is sent from port P2 and data addressed to ECU2 is sent from port P1. Also, it is set so that data addressed to the SDN controller 10 is sent from ports P1 and P2. Also, it is set so that data addressed to the relay devices R1, R3, and R4 is sent from ports P1 and P2.

[0036] That is, in the relay device R2, data addressed to the relay devices R1, R3, and R4 is sent from multiple ports, ports P1 and P2, and the multiple relay devices R1 and R4 arranged adjacently can receive the data addressed to the relay devices R1, R3, and R4. Also, in the relay device R2, data addressed to the SDN controller 10 is sent from ports P1 and P2, and the multiple relay devices R1 and R4 arranged adjacently can receive the data.

[0037] Next, as shown in Fig. 2C, the network configuration information for the relay device R3 is set so that data addressed to ECU1 is sent from port P3 and data addressed to ECU2 is sent from port P2. Also, it is set so that data addressed to the SDN controller 10 is sent from ports P1 and P2. Also, it is set so that data addressed to the relay devices R1, R2, and R4 is sent from ports P1 and P2.

[0038] That is, similarly, in the relay device R3, the multiple relay devices R1 and R4 arranged adjacent to each other can receive data addressed to the SDN controller 10 and data addressed to the relay devices R1, R2, and R4.

[0039] Next, as shown in Fig. 2D, the network configuration information of the relay device R4 is set so that data addressed to ECU1 is sent from port P1 and data addressed to ECU2 is sent from port P3. Also, it is set so that data addressed to the SDN controller 10 is sent from ports P1 and P2. Also, it is set so that data addressed to the relay devices R1, R2, and R3 is sent from ports P1 and P2.

[0040] That is, similarly, in the relay device R4, the multiple relay devices R2 and R3 arranged adjacent to each other can receive data addressed to the SDN controller 10 and data addressed to the relay devices R1, R2, and R3.

[0041] In this way, the relay devices R1 to R4 are physically and logically connected to multiple other relay devices R1 to R4 so that data addressed to the other relay devices R1 to R4 can be sent to multiple relay devices R1 to R4 that are located adjacent to each other.

[0042] [1-3. Changing network configuration information] The SDN controller 10 can arbitrarily change the network configuration information held by the relay devices R1 to R4. This process will be described with reference to Figures 3A to 3D and 4A to 4C.

[0043] Although the SDN controller 10 can change the network configuration information even during initial setup, this embodiment will be described assuming a case where a failure such as a disconnection occurs in the link (e.g., communication line) connecting the relay devices R3 and R4, as shown in Figure 4A. When a failure occurs in the link connecting the relay devices R3 and R4, the failure detection units 24 of the relay devices R3 and R4 detect the failure. For example, if no response is received within a predetermined time after sending data, the failure detection unit 24 determines that a failure has occurred in the link.

[0044] When the fault detection unit 24 determines that a fault has occurred, the fault notification unit 25 of each of the relay devices R3 and R4 sends a link fault notification indicating that a link has failed to the SDN controller 10 in accordance with the network configuration information. The link fault notification includes information for identifying the failed link. The link fault notification is sent from ports P1 and P2 of the relay devices R3 and R4, respectively.

[0045] The link fault notification sent from relay device R3 is received by the SDN controller 10 via relay device R1. In addition, the link fault notification sent from relay device R4 is received by the SDN controller 10 via relay devices R2 and R1. At this time, the frame receiving units 26 of relay devices R1 and R2 recognize the link fault notification, and the second transmitting unit 29 sends this link fault notification as data addressed to the SDN controller 10.

[0046] In the SDN controller 10, the fault receiver 16 recognizes the link fault notification, and the generator 17 generates information (i.e., new network configuration information) for reconfiguring the communication path to avoid the faulty link and perform communication. Specifically, as shown in Figure 3C, the SDN controller 10 changes the network configuration information of the relay device R3 so that data addressed to ECU2 is sent from port P1. Also, as shown in Figure 3D, the SDN controller 10 changes the network configuration information of the relay device R4 so that data addressed to ECU1 is sent from port P2.

[0047] The changed network configuration information is sent to relay devices R1 to R4 as shown in Fig. 4B. In detail, first, the setting notification unit 18 [1] sends the changed network configuration information shown in Fig. 3A to relay device R1 that is directly connected to the SDN controller 10. Next, the setting notification unit 18 [2] sends the changed network configuration information shown in Fig. 3B and Fig. 3C to relay devices R2 and R3 that are adjacent to relay device R1.

[0048] Next, the setting notification unit 18 sends [3] the changed network configuration information shown in Fig. 3D to the relay device R4. Note that in the example of this embodiment, since the network configuration information in the relay devices R1 and R2 has not been changed, the process of sending the network configuration information to the relay devices R1 and R2 may be omitted.

[0049] In this way, the relay devices R1 to R4 that have received the network configuration information from the SDN controller 10 each update the network configuration information, and a new communication path between ECU1 and ECU2 is established as shown in Fig. 4C. That is, ECU1 can send data to ECU2 by having the data relayed in the order of relay devices R3, R1, R2, and R4.

[0050] [1-4. Comparison with conventional configuration] The configuration of this embodiment includes the network configuration information shown in Figures 2A to 2D. That is, the relay devices R1 to R4 are configured to be physically and logically connected to multiple relay devices R1 to R4 via multiple communication paths. Specifically, data addressed to the SDN controller 10 and the relay devices R1 to R4 is configured to be sent from both ports P1 and P2.

[0051] However, in the conventional configuration, for example, network configuration information such as that shown in Figures 5A to 5D is provided. That is, the configuration is such that data addressed to the SDN controller 10 and the relay devices R1 to R4 is sent from only one of ports P1 and P2.

[0052] Specifically, as shown in Fig. 5A, the network configuration information of the relay device R1 is set so that data addressed to the relay device R2 is sent only from port P1, and data addressed to the relay devices R3 and R4 is sent only from port P2. Also, as shown in Fig. 5B, the network configuration information of the relay device R2 is set so that data addressed to the relay device R1 is sent only from port P2, and data addressed to the SDN controller 10 and the relay devices R3 and R4 is sent only from port P1.

[0053] 5C, the network configuration information of the relay device R3 is set so that data addressed to the SDN controller 10 and the relay devices R1 and R2 is sent only from port P1, and data addressed to the relay device R4 is sent only from port P2. Also, as shown in FIG. 5D, the network configuration information of the relay device R4 is set so that data addressed to the SDN controller 10 and the relay device R3 is sent only from port P1, and data addressed to the relay devices R1 and R2 is sent only from port P2.

[0054] In such a conventional configuration, although the relay devices R1 to R4 are physically connected to multiple relay devices R1 to R4 via multiple communication paths, they are only logically connected via one communication path. Therefore, when updating the network configuration information, it is first necessary to establish a new logical connection between the relay devices R1 to R4. In addition, at this time, it is also necessary to change the destination port of the SDN controller 10 and the destination ports of the relay devices R1 to R4. This means that there is more dynamically changing information than in the configuration of the above embodiment, making management more complicated.

[0055] Specifically, as shown in FIG. 4A, if a failure occurs between relay devices R3 and R4, in a system with a conventional configuration, it is necessary to change the destination port of the SDN controller 10 and the destination ports of the relay devices R1 to R4, as shown in FIGS. 6A to 6D. In other words, it is necessary to perform processing that is unnecessary in the configuration of this embodiment. In other words, in a system with a conventional configuration, it is necessary to establish a logical link to avoid the failure and to sequentially change the destination port of the SDN controller 10 and the destination ports of the relay devices R1 to R4 in the network configuration information. Note that the destination ports for ECU1 and 2 are changed in the same way as in this embodiment.

[0056] [1-3.Effects] According to the embodiment described above in detail, the following effects are achieved. (1a) One aspect of the present disclosure is a communication system 100 including a plurality of relay devices R1 to R4 and an SDN controller 10. The plurality of relay devices R1 to R4 are connected in a ring shape on a plurality of communication paths for a plurality of communication devices (e.g., ECU1 and ECU2) to communicate with each other. The SDN controller 10 is configured to manage the plurality of relay devices R1 to R4.

[0057] At least one relay device R1 among the multiple relay devices R1 to R4 is communicatively connected to the SDN controller 10. In particular, the relay device R1 is communicatively connected to the SDN controller 10 without going through multiple communication paths for communication between ECU1 and ECU2.

[0058] The plurality of relay devices R1 to R4 each include a frame receiving unit 26 and a frame transmitting unit 27. The frame receiving unit 26 is configured to receive a frame transmitted from the SDN controller 10. The frame transmitting unit 27 (for example, a first transmitting unit 28) is configured to transmit the frame received by the frame receiving unit 26 to a plurality of adjacently connected relay devices R2 and R3 among the plurality of relay devices R1 to R4.

[0059] According to this configuration, the relay devices R1 to R4 transmit frames sent from the SDN controller 10 to the adjacently connected relay devices R1 to R4, so that the frames can be delivered to all of the relay devices R1 to R4 more quickly than in the conventional configuration. Therefore, the time required to establish a communication path can be further reduced.

[0060] (1b) In the above embodiment, the plurality of relay devices R1 to R4 further includes a second transmission unit 29. When the second transmission unit 29 receives a frame addressed to the SDN controller 10, the second transmission unit 29 is configured to transmit the frame to the plurality of adjacently connected relay devices R1 to R4.

[0061] According to this configuration, the multiple relay devices R1 to R4 can relay frames addressed to the SDN controller 10 to the multiple other relay devices R1 to R4. Therefore, even if a communication abnormality occurs in one communication path, frames addressed to the SDN controller 10 can be delivered to the SDN controller 10 more quickly.

[0062] (1c) In one aspect of the present disclosure, the plurality of relay devices R1 to R4 further include a failure detection unit 24 and a failure notification unit 25. The failure detection unit 24 is configured to detect link failures in the plurality of communication paths. The failure notification unit 25 is configured to notify the SDN controller 10 of a link failure notification when a failure is detected.

[0063] The SDN controller 10 includes a fault receiving unit 16, a generating unit 17, and a setting notifying unit 18. The fault receiving unit 16 is configured to receive link fault notifications from the relay devices R1 to R4. The generating unit 17 is configured to generate new network configuration information based on the link fault information so as to avoid the failed link. The setting notifying unit 18 is configured to notify the new network configuration information.

[0064] With this configuration, when a relay device R1 to R4 detects a failure, the SDN controller 10 can generate and notify new network configuration information for communication that avoids the link with the failure in the communication path. At this time, the network configuration information can be deployed to all relay devices R1 to R4 more quickly.

[0065] 2. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0066] (2a) In the above embodiment, the SDN controller 10 is connected only to the port P3 of the relay device R1, but this is not limiting. For example, as shown by the dashed lines in Fig. 1, the SDN controller 10 may be dual-connected to the ports P3 and P4 of the relay device R1, or may be connected to both the relay device R1 and the relay device R2.

[0067] In other words, the SDN controller 10 may be connected to two or more relay devices R1 to R4 without using multiple communication paths. With this configuration, even if a communication failure occurs between the SDN controller 10 and one of the relay devices R1 to R4, redundancy is provided, so that communication can be ensured. (2b) In the above embodiment, a link failure triggers the SDN controller 10 to generate new network configuration information and notify the relay devices R1 to R4 of the new network configuration information. However, this is not limiting. For example, the relay devices R1 to R4 may each include an information acquisition unit that acquires the communication status of the link to which they are connected, and when the communication status satisfies a predetermined condition, the SDN controller 10 may notify the SDN controller 10, and the SDN controller 10 may generate new network configuration information. Here, the predetermined condition may include the communication quality of the link being equal to or lower than a predetermined value, or the amount of communication data on the link being equal to or higher than a predetermined value, etc. (2c) In the above embodiment, the SDN controller 10 generates new network configuration information in response to a link failure and notifies the relay devices R1 to R4 of the new network configuration information. However, this is not limiting. For example, the SDN controller 10 may generate new network configuration information in response to a vehicle switching to a specific mode. The switching to the specific mode may include at least one of the following: switching to a driving assistance mode including autonomous driving level 2; switching to an autonomous driving mode including autonomous driving level 3 or higher; switching from the driving assistance mode or autonomous driving mode to a manual driving mode; switching to an OTA mode for updating the vehicle system; and switching to a mode for collecting information within the vehicle system. The autonomous driving levels are determined based on standards established by the Society of Automotive Engineers (SAE). (2d) In the above embodiment, the SDN controller 10 is provided separately from the relay devices R1 to R4, but this is not limited to this. For example, one of the relay devices R1 to R4 may execute the functions of a general SDN controller, as well as the functions of the fault receiving unit 16, the generating unit 17, and the setting notifying unit 18. In this case, it is not necessary to provide the SDN controller 10.

[0068] (2e) Each device described in this disclosure (i.e., ECUs 1-2, SDN controller 10, and relay devices R1-R4) and the method implemented by each device may be implemented by a dedicated computer configured by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, each device described in this disclosure and the method implemented by each device may be implemented by a dedicated computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, each device described in this disclosure and the method implemented by each device may be implemented by one or more dedicated computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, a computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium. The method for implementing the functions of each unit included in each device does not necessarily need to include software; all of the functions may be implemented using one or more hardware.

[0069] (2f) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0070] (2g) In addition to the communication system 100 described above, the present disclosure can also be realized in various forms, such as each device that constitutes the communication system 100, a program for causing a computer to function as each device, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a communication method.

[0071] [3. Technical Ideas Disclosed in the Present Specification] [Item 1] A communication system (100) comprising: a plurality of relay devices (R1, R2, R3, R4) connected in a ring shape on a plurality of communication paths for a plurality of communication devices (1, 2) to communicate with each other; and an SDN controller (10) configured to manage the plurality of relay devices, At least one relay device among the plurality of relay devices, communicatively coupled to the SDN controller; a frame receiving unit (26) configured to receive frames transmitted from the SDN controller; a frame transmitting unit (27) configured to transmit the received frame to a plurality of adjacently connected relay devices among the plurality of relay devices; A communication system comprising:

[0072] [Item 2] Item 1, a communication system according to the present invention, The frame transmitting unit is a first transmitting unit (28), the plurality of relay devices, a second transmission unit (29) configured to, upon receiving a frame addressed to the SDN controller, transmit the frame to the plurality of adjacently connected relay devices; The communication system further comprises:

[0073] [Item 3] The communication system according to item 1 or 2, the plurality of relay devices, a failure detection unit (24) configured to detect failures in links in the plurality of communication paths; a fault notification unit (25) configured to notify the SDN controller of a link fault notification when the fault is detected; Furthermore, The SDN controller a fault receiving unit (16) configured to receive the link fault notification from the relay device; a generating unit (17) configured to generate new network configuration information based on the link fault notification so as to avoid the failed link; a setting notification unit (18) configured to notify the new network configuration information; A communication system comprising:

[0074] [Item 4] A communication system according to any one of items 1 to 3, A communication system in which the SDN controller is connected to two or more of the relay devices without going through the multiple communication paths. [Explanation of symbols]

[0075] 1-2...ECU, 10...SDN controller, 11...CPU, 12...memory, 16...fault receiving unit, 17...generation unit, 18...setting notification unit, 21...CPU, 22...memory, 24...fault detection unit, 25...fault notification unit, 26...frame receiving unit, 27...frame transmitting unit, 28...first transmitting unit, 29...second transmitting unit, 31...CPU, 32...memory, 100...communication system, P1-P4...ports, R1-R4...relay devices.

Claims

1. A communication system (100) comprising: a plurality of relay devices (R1, R2, R3, R4) connected in a ring shape on a plurality of communication paths for a plurality of communication devices (1, 2) to communicate with each other; and an SDN controller (10) configured to manage the plurality of relay devices, At least one relay device among the plurality of relay devices, communicatively coupled to the SDN controller; a frame receiver (26) configured to receive frames transmitted from the SDN controller; a frame transmitting unit (27) configured to transmit the received frame to a plurality of adjacently connected relay devices among the plurality of relay devices; A communication system comprising:

2. 2. The communication system of claim 1, The frame transmitting unit is a first transmitting unit (28), the plurality of relay devices, a second transmitting unit (29) configured to, upon receiving a frame addressed to the SDN controller, transmit the frame to the plurality of adjacently connected relay devices; The communication system further comprises:

3. 3. The communication system according to claim 1 or 2, the plurality of relay devices, a failure detection unit (24) configured to detect failures of links in the plurality of communication paths; a fault notification unit (25) configured to notify the SDN controller of a link fault notification when the fault is detected; Furthermore, The SDN controller a fault receiving unit (16) configured to receive the link fault notification from the relay device; a generating unit (17) configured to generate new network configuration information based on the link fault notification so as to avoid the failed link; a setting notification unit (18) configured to notify the new network configuration information; A communication system comprising:

4. 3. The communication system according to claim 1 or 2, A communication system in which the SDN controller is connected to two or more of the relay devices without passing through the multiple communication paths.

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