Relay device, relay system, relay method, and computer program

Abstract

To enable timely relay while suppressing power consumption.SOLUTION: An in-vehicle relay device relays an Ethernet frame, and includes: a plurality of PHY units respectively corresponding to a plurality of in-vehicle devices; a switch unit connected with the plurality of PHY units are connected; and a control unit that monitors operating states of the plurality of PHY units. The plurality of PHY units include at least one predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to reception of a predetermined control signal different from the Ethernet frame. Upon detecting the Ethernet frame to be transmitted from the predetermined PHY unit while the predetermined PHY unit is in the sleep state, the control unit performs switching control to switch the predetermined PHY unit into the operating state.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a relay device, a relay system, a relay method, and a computer program. [Background technology]

[0002] There is known an in-vehicle network that includes multiple ECUs (Electronic Control Units) and a relay device that relays frames transmitted and received between the multiple ECUs. The ECUs may be put into a sleep state to reduce power consumption. Since an ECU in a sleep state cannot receive frames, a technology is required to wake up the ECU in a timely manner.

[0003] For example, Patent Document 1 discloses a technique for waking up a master in-vehicle communication device (ECU) in a sleep state from a slave in-vehicle communication device (relay device) in a network conforming to the 100Base-T1 communication protocol. When the master in-vehicle communication device is in a sleep state, the slave in-vehicle communication device does not output a signal (idle signal) for waking up the master in-vehicle communication device.

[0004] For this reason, in Patent Document 1, a predetermined signal having a pattern almost identical to that of an idle signal is transmitted from a slave vehicle-mounted communication device to a master vehicle-mounted communication device. Then, when the predetermined signal is detected by a detection circuit included in the master vehicle-mounted communication device and continuing to operate even during a sleep state, the detection circuit outputs a predetermined power supply instruction signal to a power supply circuit. This wakes up the master vehicle-mounted communication device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-72568 Summary of the Invention [Problem to be solved by the invention]

[0006] The relay device has a PHY (Physical Layer) unit for each of a plurality of ECUs. For example, the PHY unit is switched from an operating state to a sleep state in response to the corresponding ECU going into a sleep state. Since the PHY unit in the sleep state cannot transmit or receive frames, conventionally, the relay device has not been able to relay frames addressed to the ECU in the sleep state.

[0007] In view of the above problem, an object of the present disclosure is to provide a relay device, a relay system, a relay method, and a computer program that are capable of timely relaying while suppressing power consumption. [Means for solving the problem]

[0008] The relay device of the present disclosure is an in-vehicle relay device that relays Ethernet frames, and is equipped with a plurality of PHY units corresponding respectively to a plurality of in-vehicle devices, a switch unit to which the plurality of PHY units are connected, and a control unit that monitors the operating states of the plurality of PHY units, wherein the plurality of PHY units include a predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to receiving a predetermined control signal different from the Ethernet frame, and the control unit executes switching control to switch the predetermined PHY unit to the operating state when it detects the Ethernet frame to be transmitted from the predetermined PHY unit during a period in which the predetermined PHY unit is in a sleep state.

[0009] The relay method disclosed herein is a relay method in which an Ethernet frame is relayed by an in-vehicle relay device, the relay device comprising: a plurality of PHY units, each corresponding to a plurality of in-vehicle devices, including a predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to receipt of a predetermined control signal different from the Ethernet frame; and a switch unit to which the plurality of PHY units are connected, the relay method comprising the steps of: detecting the Ethernet frame to be transmitted from the predetermined PHY unit while the predetermined PHY unit is in a sleep state; and switching the predetermined PHY unit to an operating state when the Ethernet frame is detected.

[0010] The computer program of the present disclosure is a computer program for relaying an Ethernet frame by an in-vehicle relay device, the relay device comprising: a plurality of PHY units, each corresponding to a plurality of in-vehicle devices, including a predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to receipt of a predetermined control signal different from the Ethernet frame; and a switch unit to which the plurality of PHY units are connected, the computer program comprising: a step of causing a computer to detect the Ethernet frame to be transmitted from the predetermined PHY unit while the predetermined PHY unit is in a sleep state; and a step of switching the predetermined PHY unit to an operating state when the Ethernet frame is detected. Effect of the Invention

[0011] According to the present disclosure, it is possible to suppress power consumption and enable relaying at the appropriate time. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram showing a configuration of a relay system according to an embodiment. [Diagram 2] FIG. 2 is a sequence diagram illustrating an example of a relay method according to the embodiment. [Diagram 3]FIG. 3 is a flowchart illustrating an example of a relay method according to the embodiment. [Figure 4] FIG. 4 is a sequence diagram showing a relay method according to a modified example. [Diagram 5] FIG. 5 is a flowchart showing a relay method according to a modified example. [Figure 6] FIG. 6 is a sequence diagram showing a relay method according to a modified example. [Figure 7] FIG. 7 is a flowchart showing a relay method according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Description of the embodiments of the present disclosure] The gist of the present disclosure includes the following configurations.

[0014] (1) The relay device of the present disclosure is an in-vehicle relay device that relays Ethernet frames, and includes a plurality of PHY units corresponding to a plurality of in-vehicle devices, a switch unit to which the plurality of PHY units are connected, and a control unit that monitors the operating states of the plurality of PHY units, wherein the plurality of PHY units include a predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to receiving a predetermined control signal different from the Ethernet frame, and the control unit executes switching control to switch the predetermined PHY unit to the operating state when it detects the Ethernet frame to be transmitted from the predetermined PHY unit during a period in which the predetermined PHY unit is in a sleep state.

[0015] With this configuration, the PHY unit can be put into a sleep state as appropriate to reduce power consumption, while the PHY unit can be woken up when necessary, enabling relaying at the appropriate time.

[0016] (2) Preferably, the control unit has a frame memory unit that stores the Ethernet frame to be transmitted from the specified PHY unit, and after executing the switching control, the control unit executes transfer control to output the Ethernet frame stored in the frame memory unit to the specified PHY unit.

[0017] With this configuration, it is not necessary to retransmit the Ethernet frame from the vehicle-mounted device to the relay device, and therefore the communication load imposed by the retransmission of the Ethernet frame can be reduced.

[0018] (3) Preferably, the switching control and the transfer control are performed on the condition that the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a first predetermined condition.

[0019] With this configuration, switching control and transfer control are executed only when a first predetermined condition is satisfied, for example when the need for transfer is high, and when the first predetermined condition is not satisfied, a predetermined PHY unit is kept in a sleep state and no Ethernet frame transfer is performed. This makes it possible to reduce power consumption in the relay device when the need for transfer is low.

[0020] (4) Preferably, the first predetermined condition includes that the data contained in the Ethernet frame to be transmitted from the predetermined PHY unit has a priority regarding vehicle traveling safety of a predetermined level or higher.

[0021] With this configuration, it is possible to determine which Ethernet frames are most likely to be transferred based on the priority.

[0022] (5) Preferably, when the Ethernet frame to be transmitted from the specified PHY section satisfies a second specified condition, the control unit does not execute the transfer control, but executes a retransmission request control to request a source of the Ethernet frame to retransmit the Ethernet frame.

[0023] By configuring in this manner, it is possible to switch between performing transfer control and performing retransmission request control depending on whether a second specified condition is met, thereby making it possible to relay Ethernet frames in a more appropriate manner according to the situation.

[0024] (6) Preferably, the second specified condition includes that the type of data contained in the Ethernet frame to be transmitted from the specified PHY unit is a specified type, that the amount of data in the Ethernet frame to be transmitted from the specified PHY unit exceeds a specified amount, or that the Ethernet frame to be transmitted from the specified PHY unit is one of a plurality of divided frames.

[0025] By setting a condition under which retransmission is more preferable than proxy forwarding for an Ethernet frame as the second predetermined condition, it is possible to relay the Ethernet frame more appropriately according to the situation.

[0026] (7) Preferably, after executing the switching control, the control unit executes a retransmission request control for requesting a source of an Ethernet frame to be transmitted from the predetermined PHY unit to retransmit the Ethernet frame.

[0027] With this configuration, the processing load on the relay device can be reduced.

[0028] (8) Preferably, the switch section has a rule memory section in which rules are stored for determining whether or not to output the Ethernet frame to be transmitted from the specified PHY section to the control unit, and the control unit changes the rules so that, when the specified PHY section is in a sleep state, the Ethernet frame to be transmitted from the specified PHY section is output to the control unit.

[0029] By changing the rules, Ethernet frames that were not output to the control unit before the rule change are now output to the control unit, allowing the control unit to peek (snoop) at the contents of Ethernet frames that it was not able to monitor before the rule change.

[0030] (9) Preferably, the Ethernet frame to be transmitted from the specified PHY unit is a frame whose source is an in-vehicle device among the plurality of in-vehicle devices that belongs to the same VLAN (Virtual Local Area Network) as the in-vehicle device corresponding to the specified PHY unit.

[0031] In such a case, the Ethernet frame to be sent from a specific PHY unit can be relayed by the switch unit acting as an L2 switch, and the Ethernet frame is not normally output to the control unit. In such a case, in order for the control unit to perform switching control based on the contents of the Ethernet frame, the control unit needs to peek at the contents of the Ethernet frame by changing the rules as described above in (8).

[0032] (10) Preferably, the Ethernet frame to be transmitted from the specified PHY unit is a frame whose source is an in-vehicle device among the plurality of in-vehicle devices that belongs to a different VLAN (Virtual Local Area Network) from the in-vehicle device corresponding to the specified PHY unit.

[0033] In such a case, the Ethernet frame to be transmitted from a specific PHY unit is output to the control unit as an L3 switch. In such a case, the rule change as described above in (8) is not required so that the control unit can perform switching control based on the contents of the Ethernet frame.

[0034] (11) Preferably, the predetermined PHY unit complies with TC10 (Tech Committees 10) of the OPEN ALLIANCE.

[0035] By configuring in this manner, a specified control signal for waking up an in-vehicle device corresponding to a specified PHY unit is generated and output in a specified PHY unit, so that the control unit does not need to generate a specified control signal for waking up the in-vehicle device, thereby reducing the processing load on the control unit.

[0036] (12) A relay system according to the present disclosure includes the relay device according to any one of (1) to (11) and the plurality of vehicle-mounted devices.

[0037] (13) A relay method disclosed herein is a relay method in which an Ethernet frame is relayed by an in-vehicle relay device, the relay device comprising: a plurality of PHY units, each corresponding to a plurality of in-vehicle devices, including a predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to receipt of a predetermined control signal different from the Ethernet frame; and a switch unit to which the plurality of PHY units are connected, the relay method comprising the steps of: detecting the Ethernet frame to be transmitted from the predetermined PHY unit while the predetermined PHY unit is in a sleep state; and switching the predetermined PHY unit to an operating state when the Ethernet frame is detected.

[0038] With this configuration, the PHY unit can be put into a sleep state as appropriate to reduce power consumption, while the PHY unit can be woken up when necessary, enabling relaying at the appropriate time.

[0039] (14) A computer program of the present disclosure is a computer program for relaying an Ethernet frame by an in-vehicle relay device, the relay device comprising: a plurality of PHY units, each corresponding to a plurality of in-vehicle devices, including a predetermined PHY unit whose operating state is switched between a sleep state and an operating state in response to receipt of a predetermined control signal different from the Ethernet frame; and a switch unit to which the plurality of PHY units are connected, the computer program comprising, in a computer, a step of detecting the Ethernet frame to be transmitted from the predetermined PHY unit while the predetermined PHY unit is in a sleep state; and a step of switching the predetermined PHY unit to an operating state when the Ethernet frame is detected.

[0040] With this configuration, the PHY unit can be put into a sleep state as appropriate to reduce power consumption, while the PHY unit can be woken up when necessary, enabling relaying at the appropriate time.

[0041] 1. Details of the embodiments of the present disclosure Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the drawings.

[0042] [1.1 Relay system configuration] Fig. 1 is a block diagram showing the configuration of a relay system 10. In Fig. 1, thin lines connecting each part of the relay system 10 represent communication lines, and thick lines connecting each part of the relay system 10 represent power supply lines.

[0043] The relay system 10 is an in-vehicle system installed in a vehicle such as an automobile. The relay system 10 includes a plurality of in-vehicle devices 20 and a relay device 30.

[0044] The multiple in-vehicle devices 20 are, for example, ECUs (Electronic Control Units). To distinguish between them, three predetermined in-vehicle devices 20 included in the multiple in-vehicle devices 20 are appropriately referred to as a first ECU 21, a second ECU 22, and a third ECU 23. The number of in-vehicle devices 20 included in the relay system 10 is not particularly limited as long as it is two or more. In the relay system 10, one of the in-vehicle devices 20 among the first ECU 21, the second ECU 22, and the third ECU 23 may be omitted, or a fourth in-vehicle device 20 may be provided in addition to these three in-vehicle devices 20.

[0045] The relay device 30 is communicatively connected to each of the multiple in-vehicle devices 20, and relays frames transmitted and received between the multiple in-vehicle devices 20. That is, the multiple in-vehicle devices 20 and the relay device 30 configure an in-vehicle network.

[0046] The relay device 30 divides the in-vehicle devices 20 into a plurality of VLANs (Virtual Local Area Networks). The first ECU 21 and the second ECU 22 belong to a group G1 that is the same VLAN. The third ECU 23 belongs to a group G2 that is a different VLAN from the group G1.

[0047] [1.1.1 About frames] The frames that flow through the relay system 10 will be described. The frames include a "sleep control frame" and an "Ethernet frame." The operating states of each unit included in the relay system 10 include a sleep state and an operating state. Each unit is appropriately put into a sleep state in order to reduce power consumption. The sleep state is a state in which power consumption is reduced more than in the operating state by stopping or reducing the functions of at least a portion of the units.

[0048] The sleep control frame is a frame including a sleep signal for putting each unit included in the relay system 10 into a sleep state, or a wake-up signal for putting each unit into an operating state. That is, the sleep control frame is a frame for performing sleep control or wake-up control on each unit. Here, the sleep signal and the wake-up signal are both examples of the "predetermined control signal" of the present disclosure.

[0049] The sleep control frame is, for example, a Network Management (NM) message conforming to a predetermined communication protocol. The predetermined communication protocol is, for example, a protocol for performing sleep and wake-up control of an in-vehicle Ethernet (registered trademark).

[0050] An Ethernet frame is a frame that does not include either a sleep signal or a wake-up signal (i.e., does not include a specific control signal). In other words, an Ethernet frame is a frame different from a sleep control frame, and is a frame that has a purpose other than sleep control or wake-up control of each unit included in the relay system 10. Even if each unit receives an Ethernet frame, it is not directly triggered to undergo sleep control or wake-up control. An Ethernet frame is, for example, a frame that complies with in-vehicle Ethernet. Specific examples of Ethernet frames will be described later.

[0051] [1.1.2 Configuration of on-board equipment] The first ECU 21 is an ECU connected to, for example, a sensor (not shown) that measures the state of the vehicle. The sensor includes, for example, an on-board camera, a LIDAR (Light Detection and Ranging), an ultrasonic sensor, or a millimeter wave sensor. The first ECU 21 acquires measurement data from the sensor, and generates frames F12 and F13 (examples of "Ethernet frames") including the measurement data or data obtained by processing the measurement data. Then, the first ECU 21 transmits the frame F12 to the second ECU 22, and transmits the frame F13 to the third ECU 23.

[0052] The first ECU 21 has an MCU (Micro Control Unit) 21a, a PHY (Physical Layer) unit 21b, and a port 21c. The MCU 21a is electrically connected to the PHY unit 21b, and the PHY unit 21b is electrically connected to the port 21c. The MCU 21a has a calculation processing unit and a memory. The calculation processing unit reads out a predetermined computer program from the memory and executes it to perform various calculations and processes in the first ECU 21. For example, the MCU 21a generates frames F12 and F13 and outputs them to the PHY unit 21b.

[0053] The PHY unit 21b is a physical layer transceiver that complies with TC10 (Technical Committees 10) of the OPEN ALLIANCE, and includes a detection circuit, a transmission circuit, and a reception circuit (not shown). The detection circuit is a circuit for detecting a wake-up signal for waking up the PHY unit 21b.

[0054] The transmitting circuit and the receiving circuit perform communication in accordance with a predetermined communication protocol. The predetermined communication protocol is, for example, 100Base-T1 (IEEE802.3bw, "IEEE" is a registered trademark). The transmitting circuit converts a frame (for example, frames F12 and F13) input from the MCU 21a into a three-level signal and outputs it to the port 21c. The signalized frame is transmitted to another in-vehicle device 20 (for example, the second ECU 22 and the third ECU 23) via the relay device 30. The receiving circuit converts a signal transmitted from another in-vehicle device 20 and input to the port 21c via the relay device 30 into a frame and outputs the frame to the MCU 21a.

[0055] The second ECU 22 is an ECU connected to, for example, an actuator (not shown) that controls a vehicle. The actuator includes, for example, a motor, an engine, or a brake. The second ECU 22 controls the actuator based on the frame F12 received from the first ECU 21.

[0056] The second ECU 22 has an MCU 22a, a PHY unit 22b, and a port 22c. The MCU 22a, the PHY unit 22b, and the port 22c have the same configurations as the MCU 21a, the PHY unit 21b, and the port 21c of the first ECU 21, and therefore the description will be omitted as appropriate. For example, the MCU 22a generates a control signal for an actuator based on the measurement data included in the frame F12, and outputs the control signal to the actuator.

[0057] The third ECU 23 is an ECU connected to an in-vehicle display unit (not shown), such as a display or a speaker. The third ECU 23 displays various information on the display unit based on the frame F13 received from the first ECU 21.

[0058] The third ECU 23 has an MCU 23a, a PHY unit 23b, and a port 23c. The MCU 23a, the PHY unit 23b, and the port 23c have the same configurations as the MCU 21a, the PHY unit 21b, and the port 21c of the first ECU 21, and therefore the description will be omitted as appropriate. For example, the MCU 23a generates a display signal based on the measurement data included in the frame F13, and outputs the display signal to the display unit.

[0059] The above-mentioned functions of the first ECU 21, the second ECU 22, and the third ECU 23 are merely examples, and the functions of the first ECU 21, the second ECU 22, and the third ECU 23 are not particularly limited. For example, the first ECU 21, the second ECU 22, or the third ECU 23 may be further connected to another in-vehicle device 20 without going through the relay device 30, and may function as a relay device (i.e., a gateway ECU) that relays a frame to the other in-vehicle device 20.

[0060] [1.1.3 Relay device configuration] The relay device 30 includes a plurality of PHY units 40, a plurality of ports 50, a switch unit 60, a control unit 70, and a power supply circuit 80.

[0061] The multiple PHY units 40 are respectively connected to the multiple in-vehicle devices 20 via the ports 50. The multiple PHY units 40 each have the same configuration.

[0062] The PHY unit 40 has a similar configuration to the PHY unit 21b of the first ECU 21, and therefore a description thereof will be omitted where appropriate. That is, the PHY unit 40 is a physical layer transceiver conforming to TC10 of the OPEN ALLIANCE, and includes a detection circuit, a transmission circuit, and a reception circuit (not shown). The transmission circuit converts a frame input from the switch unit 60 into a three-level signal, and outputs the signal to the port 50. The reception circuit converts the signal input to the port 50 into a frame, and outputs the frame to the switch unit 60.

[0063] In the following, for the sake of distinction, the PHY unit 40 corresponding to the first ECU 21 will be appropriately referred to as the "first PHY unit 41", and the port 50 between the first ECU 21 and the first PHY unit 41 will be appropriately referred to as the "port 51".

[0064] Similarly, the PHY unit 40 corresponding to the second ECU 22 will be appropriately referred to as the "second PHY unit 42," and the PHY unit 40 corresponding to the third ECU 23 will be appropriately referred to as the "third PHY unit 43." Here, the second PHY unit 42 and the third PHY unit 43 are both examples of the "predetermined PHY unit" of the present disclosure. Also, the port 50 between the second ECU 22 and the second PHY unit 42 will be appropriately referred to as the "port 52," and the port 50 between the third ECU 23 and the third PHY unit 43 will be appropriately referred to as the "port 53."

[0065] The switch unit 60 has an integrated circuit (a circuit including an arithmetic circuit and a memory circuit) and functions as an L2 switch by performing various calculations and processing. Functionally, the switch unit 60 has a frame relay unit 61 and a rule memory unit 62. The frame relay unit 61 is realized by the arithmetic circuit executing a computer program stored in the memory circuit. The rule memory unit 62 is, for example, a non-volatile memory such as a flash memory.

[0066] The switch unit 60 is electrically connected to a plurality of PHY units 40. A frame input to the PHY unit 40 via the port 50 is input from the PHY unit 40 to the switch unit 60. Based on a destination MAC address (Media Access Control address) included in the frame, the frame relay unit 61 outputs the frame to another PHY unit 40 connected to the in-vehicle device 20 that is the destination of the frame.

[0067] The rule storage unit 62 stores rules for determining whether or not a frame input from the PHY unit 40 to the switch unit 60 is to be output from the switch unit 60 to the control unit 70. The rules are stored as, for example, an ACL (Access Control List) as follows:

[0068] <ACL control example> - From source "1st ECU21" to destination "2nd ECU22": Output refusal - From source "1st ECU21" to destination "3rd ECU23": Output allowed - From source "2nd ECU22" to destination "1st ECU21": Output refusal - From source "2nd ECU22" to destination "3rd ECU23": Output permission From source "3rd ECU23" to destination "1st ECU21": Output allowed From source "3rd ECU23" to destination "2nd ECU22": Output allowed

[0069] In the case of the above ACL, a frame destined for the third ECU 23 and input from the first ECU 21 to the switch unit 60 via the first PHY unit 41 is output from the switch unit 60 to the control unit 70 (output permitted). On the other hand, a frame destined for the second ECU 22 and input from the first ECU 21 to the switch unit 60 is not output from the switch unit 60 to the control unit 70 (output denied).

[0070] More specifically, when a frame crosses VLAN groups G1 and G2 (for example, when a frame is transmitted from the first ECU 21 in group G1 to the third ECU 23 in group G2), the frame is output from the switch unit 60 to the control unit 70. On the other hand, when a frame does not cross VLAN groups G1 and G2 (for example, when a frame is transmitted from the first ECU 21 in group G1 to the second ECU 22 in group G1), the frame is not output from the switch unit 60 to the control unit 70.

[0071] The control unit 70 is configured, for example, by an MCU having a calculation processing unit (CPU: Central Processing Unit) and a memory. The control unit 70 functionally has a control unit 71, a frame relay unit 72, and a frame storage unit 73. The control unit 70 may be configured by a unit having a larger calculation scale than the MCU. For example, the control unit 70 may include a GPU (Graphics Processing Unit).

[0072] The control unit 71 and the frame relay unit 72 are realized by the arithmetic processing unit executing a predetermined computer program stored in the memory. The computer program is distributed in a state stored in a computer-readable recording medium, and can be installed in the control unit 70 from the outside.

[0073] A frame input from the PHY unit 40 to the switch unit 60 is output from the switch unit 60 to the control unit 70 if it corresponds to the condition of "output permission" in the ACL stored in the rule storage unit 62. The frame relay unit 72 routes the frame based on the destination IP address (Internet Protocol address) included in the frame. The frame relay unit 72 then outputs the frame to the switch unit 60, addressed to the PHY unit 40 connected to the in-vehicle device 20 that is the destination of the frame. In other words, the frame relay unit 72 functions as an L3 switch.

[0074] The frame storage unit 73 is a volatile memory such as a RAM (Random Access Memory), etc. In the frame storage unit 73, the frame output from the switch unit 60 to the control unit 70 is temporarily stored.

[0075] The control unit 71 outputs various control commands to control each unit of the relay device 30. For example, the control unit 71 executes control to monitor the operation states of the multiple PHY units 40, control to switch the operation states of the PHY units 40 (switching control), control to output frames stored in the frame storage unit 73 (transfer control), control to change rules stored in the rule storage unit 62 (rule change control), and control to request the in-vehicle device 20 to retransmit frames (retransmission request control). Specific control contents of the control unit 71 will be described later.

[0076] The power supply circuit 80 is a circuit that converts power supplied from a power supply (not shown). The power converted in the power supply circuit 80 is supplied to each unit of the relay device 30. The power supply circuit 80 further supplies and cuts off power to each unit of the relay device 30.

[0077] For example, when the PHY unit 40 enters a sleep state, the power supply circuit 80 cuts off the power supply to the transmission circuit and reception circuit included in the PHY unit 40. On the other hand, even when the PHY unit 40 enters a sleep state, the power supply circuit 80 continues to supply power to the detection circuit of the PHY unit 40. This allows the detection circuit of the PHY unit 40 to detect a wake-up signal even in the sleep state.

[0078] [1.2 Relay method] The relay method according to this embodiment will be described with reference to FIGS. FIG. 2 is a sequence diagram illustrating an example of a relay method according to the embodiment. 3 is a flowchart showing an example of a relay method according to the embodiment. The flowchart in FIG. 3 describes the operation procedure of the control unit 70.

[0079] An example will be described below in which a frame F12 (Ethernet frame) destined for the second ECU 22 is transmitted from the first ECU 21 to the second ECU 22 via the relay device 30. The following relay method is realized by various computers (MCUs 21a and 22b, the switch unit 60, and the control unit 70) included in the relay system 10 reading and executing computer programs from their respective memories.

[0080] [1.2.1 When each component of the relay system is in operation] First, a state in which a frame F12 is transmitted when each unit of the relay system 10 is in an operating state will be described. The frame F12 is generated in the MCU 21a, and is output from the MCU 21a to the PHY unit 21b (step S101). The frame F12 is then converted into a predetermined signal in the PHY unit 21b, and is input to the first PHY unit 41 via the ports 21c and 51 (step S102). The first PHY unit 41 converts the predetermined signal into the frame F12, and outputs the frame F12 to the switch unit 60 (step S103).

[0081] Frame F12 is a frame whose output to the control unit 70 is denied by the ACL in the rule storage unit 62, and therefore is not output from the switch unit 60 to the control unit 70. Frame F12 input to the switch unit 60 is output to the second PHY unit 42 by the frame relay unit 61 (step S104), and then transmitted from the second PHY unit 42 to the PHY unit 22b (step S105). Finally, frame F12 is input from the PHY unit 22b to the MCU 22a.

[0082] In this manner, when each unit of the relay system 10 is in operation, the frame F12 is transmitted from the first ECU 21 to the second ECU 22 via the relay device 30 without any particular failure, as shown in steps S101 to S106.

[0083] [1.2.2 When some relay systems are in sleep mode] [1.2.2.1 Transition to sleep state] As described above, each unit included in the relay system 10 is always in an operating state, but is appropriately put into a sleep state to reduce power consumption. In this embodiment, a case where the second ECU 22 and the second PHY unit 42 are in a sleep state will be described as an example.

[0084] The second ECU 22 switches from an operating state to a sleep state in response to the establishment of a predetermined sleep condition. The sleep condition is not particularly limited, and may be, for example, a positive condition such as a sleep button (not shown) being pressed by a user, or a negative condition such as the second ECU 22 not receiving an Ethernet frame for a predetermined continuous period of time.

[0085] Since the PHY unit 22b complies with TC10, in an operating state, the PHY unit 22b periodically outputs a wake-up signal to the second PHY unit 42. Similarly, in an operating state, the second PHY unit 42 periodically outputs a wake-up signal to the PHY unit 22b.

[0086] When the second PHY unit 42 receives a wake-up signal from the PHY unit 22b, a detection circuit included in the second PHY unit 42 detects the wake-up signal. If the second PHY unit 42 is in an active state at this time, the second PHY unit 42 is maintained in the active state. If the second PHY unit 42 is in a sleep state, the second PHY unit 42 switches from the sleep state to the active state.

[0087] On the other hand, if the second PHY unit 42 in the operating state does not receive a wake-up signal for a predetermined period (for example, a period three times the output cycle of the wake-up signal from the PHY unit 22b), the second PHY unit 42 switches to the sleep state.

[0088] Similarly, when the PHY unit 22b receives a wake-up signal from the second PHY unit 42, a detection circuit included in the PHY unit 22b detects the wake-up signal and switches the PHY unit 22b to an operating state. If the PHY unit 22b in the operating state does not receive a wake-up signal for a predetermined period of time, the PHY unit 22b switches to a sleep state.

[0089] When a predetermined sleep condition is met, preparation for transition to sleep (step S201) is started. First, the second ECU 22 (i.e., the MCU 22a and the PHY unit 22b) enters a sleep state. In the sleep state, the PHY unit 22b does not output a wake-up signal. Therefore, the second PHY unit 42 does not receive a wake-up signal for a predetermined continuous period, and the second PHY unit 42 also switches to a sleep state. As a result, the second ECU 22 and the second PHY unit 42 enter a sleep state. In FIG. 2, the period in the sleep state is indicated by a "sleep period P1."

[0090] Conventionally, when a frame is transmitted to the second ECU 22 in a sleep state, the relay device 30 cannot relay the frame because the second PHY unit 42 is in a sleep state, resulting in frame loss. In contrast, in this embodiment, in order to prevent frame loss, the relay system 10 executes steps S202 to S218 described below.

[0091] [1.2.2.2 Start snooping] In the following description, FIG. 2 and FIG. 3 will be referred to as appropriate. The control unit 71 of the control unit 70 constantly monitors the operating state of at least one of the multiple PHY units 40 (step S10). Specifically, the control unit 71 monitors whether the PHY units 40 are in a sleep state or not. If none of the PHY units 40 are in a sleep state (i.e., in an operating state), the control unit 71 continues the monitoring (the "NO" route in step S10).

[0092] If any of the PHY units 40 is in a sleep state (the "YES" route in step S10, step S202), the control unit 71 changes the rules stored in the rule memory unit 62 that relate to the PHY units 40 in a sleep state (rule change control: steps S11, S203).

[0093] 2, the control unit 71 detects that the second PHY unit 42 is in a sleep state. Then, when an Ethernet frame (e.g., frame F12) addressed to the second ECU 22 connected to the second PHY unit 42 in a sleep state is input to the switch unit 60, the control unit 71 changes the contents of the ACL so that the Ethernet frame is output from the switch unit 60 to the control unit 70. That is, the control unit 70 sets all the controls in the ACL whose destination is the second ECU 22 to "output permitted". An example of the control of the changed ACL will be described below.

[0094] <Example of ACL control after modification> From source "1st ECU21" to destination "2nd ECU22": Output permission (changed) - From source "1st ECU21" to destination "3rd ECU23": Output allowed - From source "2nd ECU22" to destination "1st ECU21": Output refusal - From source "2nd ECU22" to destination "3rd ECU23": Output permission From source "3rd ECU23" to destination "1st ECU21": Output allowed From source "3rd ECU23" to destination "2nd ECU22": Output allowed

[0095] Due to the rule change, frame F12, which was not output to the control unit 70 before the change, is now output to the control unit 70. This enables the control unit 70 to peek (snoop) at the contents of frame F12, which it was not able to grasp before the change. Hereinafter, the period from the rule change in step S203 to the rule change in step S218 (change back to the original rule), which will be described later, is referred to as a snoop period P2.

[0096] [1.2.2.3 Frame transmission during snooping] A case will be described where frame F12 is transmitted from the first ECU 21 to the relay device 30 during snoop period P2. After changing the rule, the control unit 71 monitors whether or not a normal frame addressed to the in-vehicle device 20 connected to the PHY unit 40 in the sleep state has been input to the control unit 70 (step S12). In the example of FIG. 2, the control unit 71 monitors whether or not an Ethernet frame (e.g., frame F12) addressed to the second ECU 22 has been input to the control unit 70.

[0097] If no Ethernet frame is input ("NO" route from step S12), the control unit 71 monitors whether the PHY unit 40, whose sleep state was detected in step S10, continues to be in the sleep state (step S18). If the PHY unit 40, whose sleep state was detected in step S10, continues to be in the sleep state ("YES" route from step S18), the control unit 71 returns to step S12 and monitors again whether an Ethernet frame addressed to the second ECU 22 has been input.

[0098] In the example of FIG. 2, the sleep period P1 of the second PHY unit 42 continues until step S211 described later, so the control unit 71 repeats steps S12 and S18 until an Ethernet frame addressed to the second ECU 22 is input.

[0099] The frame F12 is input from the MCU 21a to the switch unit 60 via the PHY unit 21b and the first PHY unit 41 (steps S204, S205, S206). Next, since the snoop period P2 is in progress, the frame F12 is output from the switch unit 60 to the control unit 70 (step S207).

[0100] When the control unit 71 detects that a frame F12 destined for the second ECU 22 has been input (the "YES" route in step S12), it determines whether or not it is necessary to transfer the frame F12 to the second ECU 22, which is currently in a sleep state (step S13). For example, the control unit 71 determines that the transfer is necessary when a first predetermined condition (transfer condition) is satisfied. The first predetermined condition includes, for example, that the priority of the data included in the frame F12 is at or above a predetermined level, or that the type of the data included in the frame F12 is a predetermined type.

[0101] If the priority of the data included in the frame F12 is higher than a predetermined level, there is a high need to transfer the frame F12. Therefore, in this case, the frame F12 is stored in the frame storage unit 73, and the second ECU 22 in the sleep state is woken up to transmit the frame F12 to the second ECU 22 in the sleep state in steps S14, S15, and S16 described later. On the other hand, if the priority of the data included in the frame F12 is lower than a predetermined level, there is a low need to wake up the second ECU 22 in the sleep state to transfer the frame F12. In this case, priority is given to keeping the second PHY unit 42 and the second ECU 22 in the sleep state to suppress power consumption in the relay system 10, and the frame F12 is not transferred.

[0102] The priority of the data included in the frame F12 is, for example, a priority regarding the driving safety of the vehicle, and one example of this is the Automotive Safety Integrity Level (ASIL) of ISO26262.

[0103] Also, when the type of data included in the frame F12 is a predetermined type with high priority, there is a high need to transfer the frame F12, so the second ECU 22 in the sleep state is woken up in the same manner as above to transmit the frame F12 to the second ECU 22. Examples of the type of data with high priority include types related to vehicle control (automatic brake control for preventing collisions, control to suppress erroneous starting or reversing, etc.) and types related to warnings.

[0104] If the first predetermined condition is not met for the frame F12 (route "NO" in step S13), the control unit 71 discards the frame F12 (step S17) and returns to step S12.

[0105] If the first predetermined condition is met for frame F12 (the "YES" route of step S13, step S208), the control unit 71 stores frame F12 in the frame memory unit 73 (step S14, step S209), and then the control unit 71 executes switching control to switch the PHY unit 40 (second PHY unit 42) that detected the sleep state in step S10 from the sleep state to an operating state (step S15).

[0106] Specifically, the control unit 71 generates a frame WU1 (an example of a "sleep control frame") including a wakeup signal, and outputs it to the switch unit 60 (step S210). Next, the switch unit 60 outputs the frame WU1 to the second PHY unit 42 (step S211). When the detection circuit of the second PHY unit 42 detects the wakeup signal included in the frame WU1, the second PHY unit 42 switches from a sleep state to an active state.

[0107] Next, the second PHY unit 42, which has entered an operating state, outputs a wake-up signal to the PHY unit 22b (step S212). After this, the second PHY unit 42 periodically outputs a wake-up signal to the PHY unit 22b.

[0108] When the detection circuit of the PHY unit 22b detects the wake-up signal, the PHY unit 22b switches from a sleep state to an active state. Next, a frame WU1 including the wake-up signal is output from the PHY unit 22b to the MCU 22a (step S213), and the MCU 22a switches from a sleep state to an active state. The series of steps shown in steps S210 to S213 above are paired with the sleep transition preparation of step S201, and are also referred to as "wake-up transition preparation." With the above, the sleep period P1 of the second PHY unit 42 and the second ECU 22 ends.

[0109] After outputting the frame WU1 in step S210, the control unit 71 monitors whether the second PHY unit 42 is in an operating state (i.e., whether the second PHY unit 42 has woken up) (step S214). If the second PHY unit 42 is not in an operating state even after a predetermined time has elapsed, the control unit 71 retransmits the frame WU1 to the switch unit 60.

[0110] When the control unit 71 detects that the second PHY unit 42 is in an operating state, it terminates the switching control (step S15) and executes transfer control to output the frame F12 stored in the frame memory unit 73 to the second PHY unit 42 (step S16).

[0111] Specifically, the control unit 71 outputs the frame F12 stored in the frame storage unit 73 to the switch unit 60 (step S215). Thereafter, the frame F12 is output from the switch unit 60 to the second PHY unit 42 (step S216), from the second PHY unit 42 to the PHY unit 22b (step S217), and from the PHY unit 22b to the MCU 22a (step S218). As a result, the frame F12 stored in the frame storage unit 73 is transferred from the control unit 70 to the second ECU 22.

[0112] Conventionally, the frame F12 is transmitted from the first ECU 21 to the second ECU 22 without passing through the control unit 70 (steps S101 to S106). In this case, when the second PHY section 42 enters a sleep state, the frame F12 cannot be relayed by the relay device 30, which conventionally results in a frame loss.

[0113] In contrast, the control unit 70 of the present embodiment monitors a frame F12 to be output from the second PHY section 42 (i.e., addressed to the second ECU 22) by changing the ACL in the rule storage section 62 when the second PHY section 42 is in a sleep state. Then, when a frame F12 is input that is an Ethernet frame to be transmitted from the PHY section 40 in a sleep state and has a high need for forwarding, the control unit 70 switches the second PHY section 42 to an operating state. With this configuration, the PHY section 40 can be woken up when necessary while suppressing power consumption by appropriately putting the PHY section 40 into a sleep state, thereby enabling relaying at the appropriate time.

[0114] Furthermore, the control unit 70 temporarily stores the frame F12, and after the second PHY section 42 wakes up and becomes able to transfer the frame F12, transfers the frame F12 to the second ECU 22 instead of the first ECU 21 (transfers it as a proxy), thereby making it possible to suppress frame loss.

[0115] Furthermore, since the control unit 70 transfers the frame F12 stored in the frame storage unit 73 to the second ECU 22 after the second PHY unit 42 wakes up, there is no need to retransmit the frame F12 from the first ECU 21 to the relay device 30. This makes it possible to reduce the communication load imposed by the retransmission of the frame F12.

[0116] Furthermore, when the first ECU 21 retransmits the frame F12 to the relay device 30, the transmission of the frame F12 may be postponed depending on the timing, and it may take some time for the frame F12 to be received by the second ECU 22. In contrast, in the present embodiment, the control unit 70 transfers the frame F12 to the second ECU 22, so that the time until the frame F12 is received by the second ECU 22 can be further shortened.

[0117] After the transfer control (step S16), the control unit 71 monitors whether the PHY unit 40 (the second PHY unit 42 in the example of FIG. 2) that was detected to be in a sleep state in step S10 continues to be in the sleep state (step S18).

[0118] When the control unit 71 detects in step S18 that the PHY unit 40 (the second PHY unit 42) to be monitored is not in a sleep state (i.e., is in an operating state) (the "NO" route in step S18), it changes the rules stored in the rule storage unit 62 (steps S19 and S219). Specifically, the control unit 71 returns the rules related to the PHY unit 40 (the second PHY unit 42) that was detected in step S18 to be not in a sleep state to the state before the change in step S11.

[0119] Due to the rule change in steps S19 and S218, the frame F12 input to the switch section 60 is no longer output to the control unit 70. This ends the snooping of the contents of the frame F12 by the control unit 70. In other words, the snooping period P2 ends.

[0120] [1.2.3 Frame transmission after the snoop period ends] When the frame F12 is output from the first ECU 21 after the snoop period P2 ends, the frame F12 is transmitted to the second ECU 22 following the same route as the above steps S101 to S106 (that is, without passing through the control unit 70).

[0121] That is, frame F12 is output from MCU 21a to PHY unit 21b (step S111), passes through the first PHY unit 41, the switch unit 60 and the second PHY unit 42 (steps S112, S113, S114), is transmitted to PHY unit 22b (step S115), and finally is output from PHY unit 22b to MCU 22a (step S116).

[0122] [2. First Modification: Retransmission Control] A first modified example of the embodiment will be described below. In the first modified example, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In the first modified example, the hardware configuration of the relay system 10 is the same as that in the above embodiment.

[0123] FIG. 4 is a sequence diagram showing a relay method according to the first modified example. Fig. 5 is a flowchart showing a relay method according to Modification 1. The flowchart in Fig. 5 describes the operation procedure of the control unit 70.

[0124] The relay method of the first modified example is the same as the above embodiment up to the point where the control unit 70 executes the switching control (steps S10 to S15, S17, and steps S201 to S213), and therefore a description thereof will be omitted.

[0125] In the above embodiment, after the control unit 70 wakes up the second PHY section 42, the control unit 70 performs transfer control to output the frame F12 stored in the frame storage section 73 to the second ECU 22. In contrast, in the first modified example, after the control unit 70 wakes up the second PHY section 42 in step S15, first, the rule stored in the rule storage section 62 is restored (steps S20 and S219). This ends the snoop period P2, and the frame F12 input to the switch section 60 is no longer output to the control unit 70.

[0126] Next, the control unit 70 determines whether or not it is necessary to retransmit the frame F12 from the first ECU 21 (step S21), and in response to the determination, the control unit 70 performs transfer control (step S16) or retransmission request control (step S22).

[0127] More specifically, the control unit 70 determines whether a second predetermined condition (retransmission condition) is satisfied, and if the second predetermined condition is satisfied, determines that retransmission of the frame F12 is necessary. The second predetermined condition includes, for example, the following (A), (B), or (C). Note that the following conditions are merely examples, and the second predetermined condition may include other conditions.

[0128] <<Example of the second specified condition>> (A) The type of data contained in frame F12 is of a specified type. (B) The amount of data in frame F12 exceeds a specified amount. (C) Frame F12 is one of multiple split frames.

[0129] As described in the above embodiment, by performing proxy forwarding of frame F12 from relay device 30 to second ECU 22 (step S16, steps S215 to S218), frame F12 can be delivered to second ECU 22 in a short time while reducing the communication load compared to retransmitting frame F12 from first ECU 21.

[0130] On the other hand, in order to perform proxy forwarding, it is necessary to temporarily store frame F12 in frame storage unit 73, and therefore proxy forwarding cannot be performed if the amount of data of frame F12 exceeds the free space of frame storage unit 73. Also, in cases where multiple frames to be proxy forwarded are input to relay device 30, it is preferable to send low-priority frame F12 for retransmission in order to proxy forward high-priority frames in a shorter time. For this reason, a condition under which retransmission is more preferable than proxy forwarding for frame F12 is set as the second predetermined condition.

[0131] Specifically, when the above (A) is satisfied, there is little need to perform proxy transfer of frame F12, so the control unit 70 requests the first ECU 21 to retransmit frame F12. When the above (B) is satisfied, the frame storage unit 73 cannot store the entire frame F12, and proxy transfer cannot be performed. Therefore, in this case as well, the control unit 70 requests the first ECU 21 to retransmit frame F12.

[0132] If frame F12 is one of multiple divided frames, the amount of data before division is large, and it is highly likely that all of the multiple divided frames cannot be stored in the frame storage unit 73. Since multiple divided frames need to be combined at the destination, it is preferable to transmit them together. Therefore, even when the above (C) is satisfied, the control unit 70 requests the first ECU 21 to retransmit the frame. Frame F12 is, for example, the leading frame of the multiple divided frames that arrives at the relay device 30 first.

[0133] When the second predetermined condition is satisfied for the frame F12 (the “YES” route of step S21, step S301), the control unit 71 performs a retransmission request control to request the first ECU 21 to retransmit the frame F12 (step S22). Specifically, the control unit 71 generates a frame R1 including a retransmission request signal, and outputs the frame R1 to the first ECU 21.

[0134] Frame R1 is output from control unit 70 to switch section 60 (step S302), and is input from switch section 60 via first PHY section 41 and PHY section 21b (steps S303, S304) to MCU 21a (step S305).

[0135] Based on the frame R1, the MCU 21a outputs the frame F12 again to the second ECU 22. The frame F12 is input from the MCU 21a to the MCU 22a via the PHY unit 21b, the first PHY unit 41, the switch unit 60, the second PHY unit 42, and the PHY unit 22b (steps S306 to S311).

[0136] According to this modification, it is possible to switch between performing transfer control and performing retransmission request control depending on whether the second predetermined condition is met, so that frames can be relayed in a more suitable manner according to the situation.

[0137] In this modification, the determination of whether the second predetermined condition is satisfied (step S21) and the forwarding control (step S16) may not be performed, and the retransmission request control (step S22) may be performed immediately after the rule change control (step S20). For example, in the relay system 10, when the need for proxy forwarding is low, it is preferable to perform only the retransmission request control without selecting between the forwarding control and the retransmission request control, since this reduces the processing load on the relay device 30.

[0138] [3. 2nd Variation: No rule changes] A second modification of the embodiment will be described below. In the second modification, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In the second modification, the hardware configuration of the relay system 10 is the same as that in the above embodiment.

[0139] FIG. 6 is a sequence diagram showing a relay method according to the second modified example. Fig. 7 is a flowchart showing a relay method according to Modification 2. The flowchart in Fig. 7 describes the operation procedure of the control unit 70.

[0140] In the above embodiment, an example is given of a case where the frame F12 is transmitted from the first ECU 21 to the second ECU 22. In the second modified example, a case where the frame F13 is transmitted from the first ECU 21 to the third ECU 23 will be described.

[0141] Since the first ECU 21 and the second ECU 22 belong to group G1 of the same VLAN, frame F12 can be relayed by the switch section 60 as an L2 switch, and frame F12 is not output to the control unit 70 until snooping is started in step S203. In contrast, since the first ECU 21 and the third ECU 23 belong to groups G1 and G2 of different VLANs, respectively, frame F13 needs to be relayed by the frame relay section 72 as an L3 switch, and frame F13 is output to the control unit 70 even if snooping is not started in step S203.

[0142] For this reason, in the relay method of the second modification, steps corresponding to steps S11 and S19 for changing the rule in the above embodiment are omitted, thereby reducing the processing load on the relay device 30 while suppressing loss of the frame F13.

[0143] [3.1 When each component of the relay system is in operation] A state in which the frame F13 is transmitted when each unit of the relay system 10 is in an operating state will be described. Like the frame F12, the frame F13 is output from the MCU 21a, passes through the PHY unit 21b and the first PHY unit 41, and is input to the switch unit 60 (steps S121, S122, S123).

[0144] In the ACL of the rule storage section 62, the frame F13 transmitted from the first ECU 21 to the third ECU 23 is "permitted to be output" to the control unit 70, so the switch section 60 outputs the frame F13 to the control unit 70 (step S124).

[0145] Then, the frame relay unit 72 of the control unit 70 performs routing, and the frame F13 is output from the control unit 70 to the switch unit 60 (step S125), and then output from the switch unit 60 to the third PHY unit 43 (step S126). The frame F13 is input from the third PHY unit 43 through the PHY unit 23b (step S127) to the MCU 23a (step S128).

[0146] In this manner, when each part of the relay system 10 is in operation, the frame F13 is transmitted from the first ECU 21 to the third ECU 23 via the relay device 30 (the switch part 60 and the control unit 70) without any particular failure, as shown in steps S121 to S128.

[0147] [3.2 When some relay systems are in sleep mode] The third ECU 23 and the third PHY unit 43 perform preparation for sleep transition (step S201) in the same manner as the second ECU 22 and the second PHY unit 42. That is, in response to the establishment of a predetermined sleep condition, the third ECU 23 enters a sleep state, and the output of a wake-up signal from the PHY unit 23b to the third PHY unit 43 is stopped. Then, since the third PHY unit 43 does not continuously receive a wake-up signal for a predetermined period of time, the third PHY unit 43 also switches to a sleep state. This starts a sleep period P1 of the third ECU 23 and the third PHY unit 43.

[0148] As in the above embodiment, the control unit 71 constantly monitors whether the PHY unit 40 is in a sleep state (step S10). In this modification, the control unit 71 detects that the third PHY unit 43 is in a sleep state (step S202, route of "YES" in step S10).

[0149] Thereafter, the control unit 71 executes monitoring of a normal frame in step S12 without performing the rule change control (steps S11 and S203) in the above embodiment. That is, the control unit 71 monitors whether or not an Ethernet frame (e.g., frame F13) destined for the third ECU 23 connected to the third PHY unit 43 has been input to the control unit 70.

[0150] The frame F13 is input from the MCU 21a via the PHY section 21b and the first PHY section 41 to the switch section 60 (steps S404, S405, S406), and is then output from the switch section 60 to the control unit 70 (step S407).

[0151] Next, the control unit 71 executes steps S13 to S18 in the same manner as in the above embodiment. That is, when the control unit 71 detects that a frame F13 addressed to the third ECU 23 has been input (the "YES" route of step S12), the control unit 71 determines whether or not it is necessary to transfer the frame F13 to the third ECU 23, which is currently in a sleep state (step S13). If the transfer is not necessary (the "NO" route of step S13), the control unit 71 discards the frame F13 (step S17) and returns to step S12.

[0152] If transfer of frame F13 is necessary (route "YES" of step S13, step S408), the control unit 71 stores frame F13 in the frame storage unit 73 (step S14, step S409). Next, the control unit 71 executes switching control to switch the PHY unit 40 (third PHY unit 43) that detected the sleep state in step S10 from the sleep state to the operating state (step S15).

[0153] Specifically, the control unit 71 generates a frame WU1 (an example of a "sleep control frame") including a wake-up signal. The frame WU1 is output from the control unit 70 and input to the third PHY unit 43 via the switch unit 60, whereby the third PHY unit 43 is switched to an operating state (steps S410 and S411).

[0154] Then, the third PHY unit 43 outputs a wake-up signal to the PHY unit 23b (step S412), and the PHY unit 23b switches to an operating state. Next, a frame WU1 including a wake-up signal is output from the PHY unit 23b to the MCU 32a (step S413), and the MCU 23a switches to an operating state. With the above, the sleep period P1 of the third PHY unit 43 and the third ECU 23 ends.

[0155] After outputting the frame WU1 in step S410, the control unit 71 monitors whether the third PHY unit 43 is in an operating state (i.e., whether the third PHY unit 43 has woken up) (step S414). If the third PHY unit 43 is not in an operating state even after a predetermined time has elapsed, the control unit 71 retransmits the frame WU1 to the switch unit 60.

[0156] When the control unit 71 detects that the third PHY unit 43 is in an operating state, it ends the switching control (step S15) and executes transfer control to output the frame F13 stored in the frame storage unit 73 to the third PHY unit 43 (step S16). The frame F13 is input from the control unit 70 to the MCU 23a via the switch unit 60, the third PHY unit 43, and the PHY unit 23b (steps S415 to S418).

[0157] In this way, the control unit 70 temporarily stores the frame F13, and after the third PHY section 43 wakes up and becomes able to transfer the frame F13, transfers the frame F13 to the third ECU 23 instead of the first ECU 21 (transfers it as a proxy). Therefore, there is no need to retransmit the frame F13 from the first ECU 21 to the relay device 30, and it is possible to reduce the communication load imposed by the retransmission of the frame F13 and suppress frame loss.

[0158] After the transfer control (step S16), the control unit 71 monitors whether the PHY unit 40 (the third PHY unit 43) that was detected to be in the sleep state in step S10 continues to be in the sleep state (step S18).

[0159] If it is detected that the PHY unit 40 (the third PHY unit 43) is not in a sleep state (i.e., is in an operating state) (the "NO" route in step S18), the rule change control in the above embodiment (steps S19, S219) is not performed, and the specified relay method is terminated.

[0160] As described above, the relay method of the second variant omits the steps corresponding to the rule change steps S11 and S19 in the above embodiment, thereby making it possible to reduce the processing load on the relay device 30 while suppressing the loss of frame F13.

[0161] [4. Other Modifications] [4.1 About the order of each step] The relay method described in the above embodiment and various modified examples is merely an example, and each step in the above relay method may be arbitrarily changed. For example, in the above embodiment, the proxy forwarding of the frame F12 by the control unit 70 (steps S215 to S218) is performed prior to the rule change by the control unit 70 (step S219).

[0162] However, the proxy forwarding by the control unit 70 (steps S215 to S218) may be executed after the rule change (step S219) by the control unit 70. For example, the rule change by the control unit 70 (step S219) may be executed in parallel with the output of the frame WU1 to the second PHY section 42.

[0163] [4.2 Variation of the sleep control frame] In the above embodiment, the PHY unit 40 switches from the operating state to the sleep state when the PHY unit 40 does not receive a wake-up signal for a predetermined period of time. That is, the sleep control frame includes a wake-up signal, and the PHY unit 40 goes into the sleep state because it "does not receive" the sleep control frame.

[0164] However, the PHY unit 40 may switch from the operating state to the sleep state when it receives a sleep signal. That is, the sleep control frame includes a sleep signal, and the PHY unit 40 goes into the sleep state because it has "received" the sleep control frame. In this case, the PHY unit 40 may switch from the sleep state to the operating state when it has not received a sleep signal for a predetermined continuous period of time, or may switch from the sleep state to the operating state when it has received a wake-up signal.

[0165] 《Addendum》 In addition, at least a part of the above-mentioned embodiment and various modified examples may be arbitrarily combined with each other. In addition, the embodiment and modified examples disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0166] 10 Relay System 20 Onboard equipment 21 1st ECU 21a MCU 21b PHY section Port 21c 22 2nd ECU 22a MCU 22b PHY section Port 22c 23 3rd ECU 23a MCU 23b PHY section Port 23c 30 Relay Device 40 PHY section 41 1st PHY part 42 Second PHY section (an example of a predetermined PHY section) 43 Third PHY unit (an example of a predetermined PHY unit) 50 Port 51 Port 52 Port 53 Port 60 Switch section 61 Frame relay unit 62 Rule Memory Section 70 Control Unit 71 Control Unit 72 Frame relay section 73 Frame Memory Unit 80 Power circuit G1 Group G2 Group F12 frame (an example of an Ethernet frame) F13 frame (an example of an Ethernet frame) WU1 frame (an example of a sleep control frame) R1 Frame P1 Sleep Period P2 snoop period

Claims

1. An in-vehicle relay device that relays Ethernet frames, a plurality of PHY units respectively corresponding to a plurality of in-vehicle devices; a switch unit to which the plurality of PHY units are connected; A control unit for monitoring the operation states of the plurality of PHY units; Equipped with the plurality of PHY units include a predetermined PHY unit whose operating state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; The control unit a frame storage unit that stores the Ethernet frame to be transmitted from the predetermined PHY unit; When detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state, executing a switching control to switch the specific PHY unit to an operating state; After executing the switching control, a transfer control is executed to output the Ethernet frame stored in the frame storage unit to the predetermined PHY unit; the switching control and the forwarding control are executed on the condition that the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a first predetermined condition; The relay device, wherein the first specified condition includes that the priority of the data contained in the Ethernet frame to be transmitted from the specified PHY unit with respect to the vehicle's driving safety is at a specified level or higher.

2. An in-vehicle relay device that relays Ethernet frames, a plurality of PHY units respectively corresponding to a plurality of in-vehicle devices; a switch unit to which the plurality of PHY units are connected; A control unit for monitoring the operation states of the plurality of PHY units; Equipped with the plurality of PHY units include a predetermined PHY unit whose operating state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; The control unit When detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state, executing a switching control to switch the specific PHY unit to an operating state; After executing the switching control, the relay device executes a retransmission request control for requesting a retransmission of an Ethernet frame to be transmitted from the specified PHY unit to a transmission source of the Ethernet frame.

3. An in-vehicle relay device that relays Ethernet frames, a plurality of PHY units respectively corresponding to a plurality of in-vehicle devices; a switch unit to which the plurality of PHY units are connected; A control unit for monitoring the operation states of the plurality of PHY units; Equipped with the plurality of PHY units include a predetermined PHY unit whose operating state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; The control unit a frame storage unit that stores the Ethernet frame to be transmitted from the predetermined PHY unit; When detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state, executing a switching control to switch the specific PHY unit to an operating state; After executing the switching control, a transfer control is executed to output the Ethernet frame stored in the frame storage unit to the predetermined PHY unit; A relay device that, when the Ethernet frame to be transmitted from the specified PHY unit satisfies a second specified condition, performs retransmission request control to request a source of the Ethernet frame to retransmit the Ethernet frame without performing the forwarding control.

4. when the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a second predetermined condition, the control unit does not execute the forwarding control, but executes a retransmission request control for requesting a source of the Ethernet frame to retransmit the Ethernet frame. The relay device according to claim 1 .

5. The second predetermined condition is: The type of data included in the Ethernet frame to be transmitted from the specified PHY unit is a specified type; The amount of data of the Ethernet frame to be transmitted from the specified PHY unit exceeds a predetermined amount, or The Ethernet frame to be transmitted from the specified PHY unit is one of a plurality of divided frames; Including, The relay device according to claim 3 or 4.

6. the switch unit has a rule storage unit in which a rule is stored for determining whether or not the Ethernet frame to be transmitted from the predetermined PHY unit is to be output from the switch unit to the control unit; the control unit changes the rule so that, when the specific PHY unit is in a sleep state, the Ethernet frame to be transmitted from the specific PHY unit is output to the control unit. The relay device according to any one of claims 1 to 5.

7. An in-vehicle relay device that relays Ethernet frames, a plurality of PHY units respectively corresponding to a plurality of in-vehicle devices; a switch unit to which the plurality of PHY units are connected; A control unit for monitoring the operation states of the plurality of PHY units; Equipped with the plurality of PHY units include a predetermined PHY unit whose operating state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; The switch unit is A part that functions as an L2 switch in relaying the Ethernet frame, a rule storage unit that stores a rule for determining whether or not the Ethernet frame to be transmitted from the predetermined PHY unit is to be output from the switch unit to the control unit; The control unit A part that functions as an L3 switch in relaying the Ethernet frame, changing the rule from a state in which the Ethernet frame to be transmitted from the specified PHY unit is not output from the switch unit to the control unit to a state in which the Ethernet frame is output when the specified PHY unit is in a sleep state; a relay device that executes switching control to switch the specified PHY unit to an operating state when the Ethernet frame to be transmitted from the specified PHY unit is detected during a period in which the specified PHY unit is in a sleep state;

8. The rule is stored in the rule storage unit as an ACL (Access Control List). The relay device according to claim 6 or 7.

9. the Ethernet frame to be transmitted from the predetermined PHY unit is a frame whose source is an in-vehicle device that belongs to the same Virtual Local Area Network (VLAN) as the in-vehicle device corresponding to the predetermined PHY unit, among the plurality of in-vehicle devices; The relay device according to any one of claims 6 to 8.

10. the Ethernet frame to be transmitted from the predetermined PHY unit is a frame whose source is an in-vehicle device that belongs to a different VLAN (Virtual Local Area Network) from the in-vehicle device corresponding to the predetermined PHY unit, among the plurality of in-vehicle devices; The relay device according to any one of claims 1 to 8.

11. The predetermined PHY unit complies with TC10 (Technical Committees 10) of OPEN ALLIANCE. The relay device according to any one of claims 1 to 10.

12. A relay device according to any one of claims 1 to 11, The plurality of in-vehicle devices; A relay system comprising:

13. A relay method for relaying an Ethernet frame by an in-vehicle relay device, comprising: The relay device is a plurality of PHY units including a predetermined PHY unit corresponding to each of a plurality of in-vehicle devices and switching an operation state between a sleep state and an active state in response to receiving a predetermined control signal different from the Ethernet frame; a switch unit to which the plurality of PHY units are connected; a frame storage unit that stores the Ethernet frame to be transmitted from the predetermined PHY unit; Equipped with The relay method includes: detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state; switching the predetermined PHY unit to an operating state when the Ethernet frame is detected; a transfer step of outputting the Ethernet frame stored in the frame storage unit to the predetermined PHY unit after the switching step is executed; Equipped with the switching step and the forwarding step are executed on the condition that the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a first predetermined condition, The relay method, wherein the first specified condition includes that the priority of the data contained in the Ethernet frame to be transmitted from the specified PHY unit with respect to the vehicle's driving safety is at a specified level or higher.

14. A relay method for relaying an Ethernet frame by an in-vehicle relay device, comprising: The relay device is a plurality of PHY units including a predetermined PHY unit corresponding to each of a plurality of in-vehicle devices and switching an operation state between a sleep state and an active state in response to receiving a predetermined control signal different from the Ethernet frame; a switch unit to which the plurality of PHY units are connected; Equipped with The relay method includes: detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state; switching the predetermined PHY unit to an operating state when the Ethernet frame is detected; a step of requesting a source of an Ethernet frame to be transmitted from the predetermined PHY unit to retransmit the Ethernet frame after the switching step is executed; The relay method includes:

15. A relay method for relaying an Ethernet frame by an in-vehicle relay device, comprising: The relay device is a plurality of PHY units, each of which corresponds to a plurality of in-vehicle devices and includes a predetermined PHY unit whose operation state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; a switch unit to which the plurality of PHY units are connected; a frame storage unit that stores the Ethernet frame to be transmitted from the predetermined PHY unit; Equipped with The relay method includes: detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state; switching the predetermined PHY unit to an operating state when the Ethernet frame is detected; a transfer step of outputting the Ethernet frame stored in the frame storage unit to the predetermined PHY unit after the switching step is executed; a retransmission request step of requesting a source of the Ethernet frame to retransmit the Ethernet frame without executing the forwarding step if the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a second predetermined condition; The relay method includes:

16. A computer program for causing an in-vehicle relay device to relay an Ethernet frame, comprising: The relay device is a plurality of PHY units, each of which corresponds to a plurality of in-vehicle devices and includes a predetermined PHY unit whose operation state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; a switch unit to which the plurality of PHY units are connected; a frame storage unit that stores the Ethernet frame to be transmitted from the predetermined PHY unit; Equipped with The computer program includes: detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state; switching the predetermined PHY unit to an operating state when the Ethernet frame is detected; a transfer step of outputting the Ethernet frame stored in the frame storage unit to the predetermined PHY unit after the switching step is executed; Run the command, the switching step and the forwarding step are executed on the condition that the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a first predetermined condition, A computer program, wherein the first specified condition includes that the priority of data contained in the Ethernet frame to be transmitted from the specified PHY unit with respect to vehicle driving safety is at a specified level or higher.

17. A computer program for causing an in-vehicle relay device to relay an Ethernet frame, comprising: The relay device is a plurality of PHY units, each of which corresponds to a plurality of in-vehicle devices and includes a predetermined PHY unit whose operation state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; a switch unit to which the plurality of PHY units are connected; Equipped with The computer program includes: detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state; switching the predetermined PHY unit to an operating state when the Ethernet frame is detected; a step of requesting a source of an Ethernet frame to be transmitted from the predetermined PHY unit to retransmit the Ethernet frame after the switching step is executed; A computer program that executes the following:

18. A computer program for causing an in-vehicle relay device to relay an Ethernet frame, comprising: The relay device is a plurality of PHY units, each of which corresponds to a plurality of in-vehicle devices and includes a predetermined PHY unit whose operation state is switched between a sleep state and an active state in response to reception of a predetermined control signal different from the Ethernet frame; a switch unit to which the plurality of PHY units are connected; a frame storage unit that stores the Ethernet frame to be transmitted from the predetermined PHY unit; Equipped with The computer program includes: detecting the Ethernet frame to be transmitted from the specific PHY unit during a period in which the specific PHY unit is in a sleep state; switching the predetermined PHY unit to an operating state when the Ethernet frame is detected; a transfer step of outputting the Ethernet frame stored in the frame storage unit to the predetermined PHY unit after the switching step is executed; a retransmission request step of requesting a source of the Ethernet frame to retransmit the Ethernet frame without executing the forwarding step if the Ethernet frame to be transmitted from the predetermined PHY unit satisfies a second predetermined condition; A computer program that executes the following:

Images