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

Abstract

To provide a relay device, a relay system, a relay method, and a computer program that securely transmit voice data of a plurality of channels in an on-vehicle network.SOLUTION: A relay system comprising a first input device (voice data reproducer), a second input device (any on-vehicle equipment other than the voice data reproducer), a plurality of first output devices (speakers), a second output device (display, speaker), a plurality of relay devices (computer device), and an Ethernet communication line includes a relay device 41 for relaying a packet including voice data from the high-order side to the low-order side of an on-vehicle network, the relay device comprising: a port unit including high-order ports P1, P2 to which high-order packets including voice data of a plurality of channels are input and low-order ports P3 to P6, each of which outputs low-order packets including voice data of one channel or a plurality of channels; and a generation unit 83 that reconstructs the upper packets to generate the low-order packets.SELECTED DRAWING: Figure 3

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] Conventionally, surround audio systems have been known in which multiple speakers are arranged to surround the user. For example, in the case of a 5.1ch surround system, five speakers and one dedicated bass speaker are installed. Surround audio data is transmitted to these speakers from an input device such as a CD player.

[0003] At this time, a technology is known in which an input device and an output device such as a speaker are connected by a cable conforming to the Ethernet (registered trademark) standard, and data is transmitted in accordance with the Ethernet AVB (Audio Video Bridging) standard. Ethernet AVB is a group of standards for transmitting video data and audio data using Ethernet.

[0004] For example, Patent Document 1 discloses a vehicle network configuration in which a plurality of end nodes (e.g., ECU: electronic control unit) included in a vehicle are connected using Ethernet AVB via a switch. When transmitting data from a first end node (talker) to a second end node (listener), communication is performed in advance to reserve a band required for transmitting the data. Specifically, an advertisement frame including information such as the maximum size of data to be transmitted is transmitted from the first end node to the second end node. When the second end node receives the advertisement frame, the second end node generates a ready frame and transmits it to the first end node. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-204857 A Summary of the Invention [Problem to be solved by the invention]

[0006] When transmitting multi-channel audio data from an input device to multiple output devices using Ethernet, such as in the surround format, it is necessary to synchronize the playback of the audio data on the multiple output devices. IEEE1722 ("IEEE" is a registered trademark) is a standard aimed at synchronizing data output on multiple output devices in this way. IEEE1722 is one of the standards included in Ethernet AVB.

[0007] For this reason, when transmitting multiple channels of audio data from an input device to multiple output devices according to IEEE 1722, it is necessary to ensure a bandwidth sufficient to transmit the audio data in all links from the input device to the multiple output devices. If a bandwidth sufficient to transmit multiple channels of audio data is not ensured, there is a risk of loss of audio data or other packets due to insufficient bandwidth.

[0008] However, since high-priority data (e.g., data for controlling the running of the vehicle) is also transmitted in the in-vehicle network along with the voice data, there is a risk that the bandwidth required to transmit the voice data of multiple channels may not be secured in the in-vehicle network. Also, the more branches an output device located at the end of the in-vehicle network, the smaller the available bandwidth tends to be, and there is a risk that the bandwidth required by IEEE1722 may not be secured.

[0009] 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 can more reliably transmit multiple-channel audio data in an in-vehicle network. [Means for solving the problem]

[0010] The relay device disclosed herein is a relay device that relays packets including voice data from the upper side to the lower side of an in-vehicle network, and includes an upper port to which an upper packet including voice data of multiple channels is input, a plurality of lower ports each outputting a lower packet including voice data of one channel or multiple channels, and a generation unit that reconstructs the upper packet to generate the lower packet, wherein the plurality of lower ports include a first lower port and a second lower port, the first lower port being the origin of a first network located below the relay device, and the second lower port being the origin of a second network located below the relay device and not sharing a node with the first network, and the generation unit constructs the voice data to be included in the lower packet output from the first lower port by deleting the voice data of a channel played in the second network from the voice data included in the upper packet.

[0011] The relay method disclosed herein is a relay method in which a relay device relays a packet including voice data from an upper side to a lower side of an in-vehicle network, the relay device having an upper port to which an upper packet including voice data of multiple channels is input, and a plurality of lower ports each outputting a lower packet including voice data of one channel or multiple channels, the plurality of lower ports including a first lower port and a second lower port, the first lower port being the origin of a first network located below the relay device, and the second lower port being the origin of a second network located below the relay device and not sharing a node with the first network, the relay method comprising a step of reconstructing the upper packet to generate the lower packet, the generating step including a step of constructing voice data to be included in the lower packet to be output from the first lower port by deleting voice data of a channel to be played in the second network from the voice data included in the upper packet.

[0012] A computer program of the present disclosure is a computer program for a relay device to relay a packet including voice data from an upper side to a lower side of an in-vehicle network, the relay device having an upper port to which an upper packet including voice data of multiple channels is input, and a plurality of lower ports each outputting a lower packet including voice data of one channel or multiple channels, the plurality of lower ports including a first lower port and a second lower port, the first lower port being the origin of a first network located below the relay device, and the second lower port being the origin of a second network located below the relay device and not sharing a node with the first network, the computer program causing a computer to execute a step of reconstructing the upper packet to generate the lower packet, the generating step including a step of constructing voice data to be included in the lower packet to be output from the first lower port by deleting voice data of a channel to be played in the second network from the voice data included in the upper packet. Effect of the Invention

[0013] According to the present disclosure, it is possible to more reliably transmit multi-channel audio data in an in-vehicle network. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing an overall configuration of a relay system according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of an arrangement of a plurality of first output devices according to the embodiment. [Diagram 3] FIG. 3 is a block diagram illustrating a schematic functional configuration of the relay device according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a packet configuration according to the embodiment. [Diagram 5] FIG. 5 is a diagram showing an example of the contents of data according to the embodiment. [Figure 6] FIG. 6 is a diagram showing data for each port constructed by the construction unit according to the embodiment. [Figure 7] FIG. 7 is a sequence diagram illustrating an example of a relay method according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating the problem to be solved by the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [Description of the embodiments of the present disclosure] The gist of the present disclosure includes the following configurations.

[0016] (1) A relay device disclosed herein is a relay device that relays packets including voice data from an upper side to a lower side of an in-vehicle network, and includes an upper port to which an upper packet including voice data of multiple channels is input, a plurality of lower ports each outputting a lower packet including voice data of one channel or multiple channels, and a generation unit that reconstructs the upper packet to generate the lower packet, wherein the plurality of lower ports include a first lower port and a second lower port, the first lower port being the origin of a first network located below the relay device, and the second lower port being the origin of a second network located below the relay device and not sharing a node with the first network, and the generation unit constructs the voice data to be included in the lower packet to be output from the first lower port by deleting the voice data of a channel played in the second network from the voice data included in the upper packet.

[0017] The lower-level packets generated by the generation unit have a smaller amount of data than the upper-level packets because they do not include audio data of channels played by nodes that are not in the first network and are located below the first lower port. Therefore, the bandwidth required to transmit the lower-level packets from the relay device to the lower side is smaller than the bandwidth required to transmit the upper-level packets directly to the lower side. As a result, it becomes easier to secure the bandwidth for transmitting packets, and audio data including multiple channels can be transmitted more reliably.

[0018] (2) Preferably, the generation unit constructs audio data to be included in the lower packet to be output from the second lower port by deleting audio data of a channel output in the first network from the audio data included in the upper packet.

[0019] The generation unit generates the lower-order packets to be output from the first lower-order port, and also generates the lower-order packets to be output from the second lower-order port. This makes it possible to reduce the bandwidth required for transmitting packets in each of the first network and the second network located below the relay device, and to more reliably transmit audio data including multiple channels.

[0020] (3) Preferably, the network further includes a relay unit that relays a connection packet transmitted from a lower node to an upper node before the upper packet is input to the upper port, and an acquisition unit that acquires channel information regarding a channel being played in at least one of the first network and the second network based on the connection packet, wherein the connection packet is a packet by which the upper node collects information regarding the lower node, and the generation unit generates the lower packet based on the channel information.

[0021] A connection packet is a packet that is transmitted to establish a connection between a higher-level node and a lower-level node. The relay device knows the channel (channel to be left or channel to be deleted) to be reproduced in the first network or the second network based on such existing packets, so there is no need to increase unnecessary packets. In other words, audio data including multiple channels can be transmitted more reliably while suppressing the increase in the burden of transmitting and receiving packets.

[0022] (4) Preferably, the connection packets include a packet conforming to a device connection state management protocol in IEEE 1722.1 and a packet conforming to a device capability discovery control protocol in IEEE 1722.1.

[0023] These packets enable the relay device to easily grasp the connection state between the lower nodes and the relay device, and the channel numbers corresponding to the respective lower nodes.

[0024] (5) Preferably, the network device further includes a filter unit that outputs the connection packet input from the lower port to the relay unit and the acquisition unit, and outputs the upper packet input from the upper port to the generation unit.

[0025] (6) Preferably, the filter unit outputs packets other than the upper layer packets and the connection packets to the relay unit.

[0026] With this configuration, the relay device has the function of reconstructing upper packets including audio data of multiple channels into lower packets, while relaying other packets as they are. Therefore, the relay device can be suitably used in an in-vehicle network in which audio data and other data are mixed.

[0027] (7) Preferably, the packets other than the upper packet and the connection packet include data detected by an on-board sensor device.

[0028] With this configuration, the relay device has the function of reconstructing upper packets including audio data of multiple channels into lower packets, while relaying data detected by the on-board sensor device as is. Therefore, the relay device can be used more effectively in an on-board network in which audio data and vehicle-related data are mixed.

[0029] (8) The relay system of the present disclosure is a relay system including any one of relay devices (1) to (7) described above, an upper node that outputs the upper packet, and a lower node that plays back audio data contained in the lower packet.

[0030] (9) A relay method disclosed herein is a relay method in which a relay device relays a packet including voice data from an upper side to a lower side of an in-vehicle network, the relay device having an upper port to which an upper packet including voice data of multiple channels is input, and a plurality of lower ports each outputting a lower packet including voice data of one channel or multiple channels, the plurality of lower ports including a first lower port and a second lower port, the first lower port being the origin of a first network located below the relay device, and the second lower port being the origin of a second network located below the relay device and having no common node with the first network, the relay method comprising a step of reconstructing the upper packet to generate the lower packet, the generating step including a step of constructing voice data to be included in the lower packet to be output from the first lower port by deleting voice data of a channel to be played in the second network from the voice data included in the upper packet.

[0031] The lower-level packet generated by the generating step does not include audio data of a channel reproduced by a node that is not in the first network and is located below the first lower port, and therefore has a smaller amount of data than the upper-level packet. Therefore, the bandwidth required to transmit the lower-level packet from the relay device to the lower side is smaller than the bandwidth required to transmit the upper-level packet directly to the lower side. As a result, it becomes easier to secure the bandwidth for transmitting packets, and audio data including multiple channels can be transmitted more reliably.

[0032] (10) A computer program of the present disclosure is a computer program for a relay device to relay a packet including voice data from an upper side to a lower side of an in-vehicle network, the relay device having an upper port to which an upper packet including voice data of multiple channels is input, and a plurality of lower ports each outputting a lower packet including voice data of one channel or multiple channels, the plurality of lower ports including a first lower port and a second lower port, the first lower port being the origin of a first network located below the relay device, and the second lower port being the origin of a second network located below the relay device and not sharing a node with the first network, the computer program causing a computer to execute a step of reconstructing the upper packet to generate the lower packet, the generating step including a step of constructing voice data to be included in the lower packet to be output from the first lower port by deleting voice data of a channel to be played in the second network from the voice data included in the upper packet.

[0033] The lower-level packet generated by the generating step does not include audio data of a channel reproduced by a node that is not in the first network and is located below the first lower port, and therefore has a smaller amount of data than the upper-level packet. Therefore, the bandwidth required to transmit the lower-level packet from the relay device to the lower side is smaller than the bandwidth required to transmit the upper-level packet directly to the lower side. As a result, it becomes easier to secure the bandwidth for transmitting packets, and audio data including multiple channels can be transmitted more reliably.

[0034] [Details of the embodiment of the present disclosure] Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the drawings.

[0035] [About the subject of this disclosure] 8 is a diagram illustrating the problem to be solved by the present disclosure. The relay system 9 includes an input device 910, a plurality of output devices 921-926, and a plurality of relay devices 931-934 connected between the input device 910 and the output devices 921-926. The relay system 9 is a system that transmits surround-sound audio data from the input device 910 to the plurality of output devices 921-926 via the relay devices 931-934. The input device 910, the output devices 921-926, and the relay devices 931-934 are each connected to each other by an Ethernet-compatible communication line 94.

[0036] The surround audio data transmitted from the input device 910 to the relay device 931 via the communication line 94 includes audio data of multiple channels (six channels in the example of FIG. 8) corresponding to all of the multiple output devices 921-926 in one packet. In the case of a conventional communication method, the packet is transmitted to the multiple output devices 921-926 with the same number of channels as before.

[0037] That is, when 6-channel audio data is transmitted from input device 910 to relay device 931, 6-channel audio data is also transmitted from relay device 931 to relay devices 932 and 934, and 6-channel audio data is also transmitted from relay device 932 to relay device 933. Then, the multiple output devices 921-926 select one channel to be played back from the received 6-channel audio data and play it back.

[0038] Therefore, for example, if a bandwidth of 11.2 Mbps is required between input device 910 and relay device 931 to transmit six channels of audio data, a bandwidth of 11.2 Mbps is also required between relay device 931 and relay device 932, between relay device 932 and relay device 933, and between relay device 933 and output device 921.

[0039] However, even if six channels of audio data are transmitted from relay device 933 to output device 921 as described above, only one of the channels is actually used by output device 921, resulting in waste of the transmitted audio data.

[0040] Therefore, the relay device of the present disclosure deletes audio data corresponding to an output device that does not exist at the destination from the surround audio data including a plurality of audio data, and then transmits the surround audio data to the lower node, thereby reducing the bandwidth required for transmitting the surround audio data and enabling the surround audio data to be transmitted more reliably.

[0041] [Overall configuration of relay system] FIG. 1 is a block diagram showing an overall configuration of a relay system 10 according to an embodiment. The relay system 10 is an in-vehicle system mounted on a vehicle V1 such as an automobile. The relay system 10 includes a first input device 21, a second input device 22, a plurality of first output devices 31, 32, 33, 34, 35, 36, a second output device 37, a plurality of relay devices 41, 42, 43, 44, and an Ethernet-compatible communication line 50. The devices 21, 22, 31-37, 41-44 are connected by the communication line 50 as shown in FIG. 1 to configure an in-vehicle network. The devices 21, 22, 31-37, 41-44 are nodes included in the in-vehicle network.

[0042] The first input device 21 and the second input device 22 are also called talkers, and are devices capable of transmitting packets (also called streams) based on Ethernet AVB. Each of the first input device 21 and the second input device 22 includes a computer device (or a microcomputer device) having an arithmetic processing unit and a storage unit.

[0043] The first input device 21 is an audio data reproducing device, such as a CD player or a DVD player. The first input device 21 reads surround audio data including audio data of multiple channels from a recording medium such as a CD, and transmits the surround audio data to the relay device 41.

[0044] The second input device 22 is any in-vehicle device other than an audio data reproducing device. The second input device 22 is, for example, an in-vehicle sensor device that detects data related to the traveling of the vehicle V1, such as a LiDAR (light detection and ranging) or a camera. In this embodiment, there is one second input device 22, but the number of second input devices 22 provided in the relay system 10 is not limited. For example, two or more second input devices 22 may be provided in the relay system 10. Also, the relay system 10 may not be provided with a second input device 22.

[0045] The first output devices 31, 32, 33, 34, 35, 36 and the second output device 37 are also called listeners and are devices that can receive a predetermined stream based on Ethernet AVB. Each of the first output devices 31, 32, 33, 34, 35, 36 and the second output device 37 includes a computer device (or a microcomputer device) having a calculation processing unit and a storage unit.

[0046] 2 is a schematic diagram illustrating an example of an arrangement of the multiple first output devices 31, 32, 33, 34, 35, 36. The multiple first output devices 31, 32, 33, 34, 35, 36 are speaker sets compatible with a 5.1ch surround system, and convert audio data transmitted from the first input device 21 into audio. The multiple first output devices 31, 32, 33, 34, 35, 36 are arranged to surround the driver's seat S1, the passenger seat S2, and the rear seat S3 of the vehicle V1.

[0047] More specifically, the first output device 31 is a center speaker installed in the front center of the driver's seat S1 and the passenger seat S2 of the vehicle V1. The first output device 32 is a left front speaker installed on the front left side of the passenger seat S2. The first output device 33 is a right front speaker installed on the front right side of the driver's seat S1. The first output devices 34 and 35 are a left rear speaker and a right rear speaker installed on the rear left side and rear right side, respectively, of the rear seat S3 of the vehicle V1. The first output device 36 is a low-frequency speaker (subwoofer) installed in the front center of the driver's seat S1 and the passenger seat S2.

[0048] In this embodiment, six first output devices 31, 32, 33, 34, 35, and 36 corresponding to the 5.1ch surround system are described as an example, but the number of first output devices is not limited as long as it is two or more. The number of first output devices may be seven (for example, compatible with the 6.1ch surround system). In addition, in this embodiment, a vehicle V1 with two rows of seats is described as an example, but the vehicle V1 may be a vehicle with one row of seats without a rear seat S3, or a vehicle with three rows of seats having two rows of rear seats S3.

[0049] Please refer to Figure 1. The second output device 37 is any in-vehicle device other than a device that converts voice data transmitted from the first input device 21 into voice. The second output device 37 is, for example, a display device (e.g., a display, a speaker) that displays data detected by the second input device 22 to the driver. The second output device 37 may be a control device (e.g., a brake control device) that controls the vehicle V1 based on the data detected by the second input device 22. In this embodiment, there is one second output device 37, but the number of second output devices 37 provided in the relay system 10 is not limited. For example, two or more second output devices 37 may be provided in the relay system 10. Also, the relay system 10 may not be provided with a second output device 37.

[0050] The multiple relay devices 41, 42, 43, and 44 are devices that relay communications between the first input device 21 and the second input device 22 and the multiple first output devices 31, 32, 33, 34, 35, and 36 and the second output device 37, respectively. The relay devices 41, 42, 43, and 44 are also called bridges or switches. Each of the multiple relay devices 41, 42, 43, and 44 includes a computer device (or a microcomputer device) having an arithmetic processing unit and a storage unit.

[0051] The relay device 41 is connected to the first input device 21, the second input device 22, the relay devices 42 and 44, the first output device 36, and the second output device 37, respectively, via communication lines 50. The relay device 42 is connected to the relay devices 41 and 43, and the first output device 33, respectively, via communication lines 50. The relay device 43 is connected to the relay device 42 and the first output devices 31 and 32, respectively, via communication lines 50. The relay device 44 is connected to the relay device 41 and the first output devices 34 and 35, respectively, via communication lines 50.

[0052] In this embodiment, the four relay devices 41, 42, 43, and 44 are connected as shown in Fig. 1, but this is an example of the present disclosure and other connection configurations may be used. For example, the relay device 43 may be omitted, and the first output devices 31 and 32 may be connected to the relay device 42.

[0053] Hereinafter, the upper side and lower side of the in-vehicle network are defined according to the direction in which a packet including a data body (for example, surround sound data, data related to the running of the vehicle V1) is transmitted. The packet is transmitted from the first input device 21, relayed by the relay devices 41-44, and received by the first output devices 31-36, respectively. The packet is also transmitted from the second input device 22, relayed by the relay device 41, and received by the second output device 37.

[0054] Focusing on the relay device 41, the first input device 21 side is the "upper side", and the relay devices 42, 44 side, the first output device 36 side, and the second output device 37 side are the "lower side". Focusing on the relay device 42, the relay device 41 side is the "upper side", and the relay device 43 side and the first output device 33 side are the "lower side".

[0055] [Repeater configuration] FIG. 3 is a block diagram showing a schematic functional configuration of relay device 41. As shown in FIG. The functional configuration of the relay devices 42, 43, and 44 is similar to that of the relay device 41, so the relay device 41 will be described representatively, and descriptions of the relay devices 42, 43, and 44 will be omitted.

[0056] The relay device 41 includes a port unit 60, an integrated circuit 70, an arithmetic processing unit 80, and a storage unit (not shown). The port unit 60 has a plurality of ports P1, P2, P3, P4, P5, P6, ... Pn for input / output. A first input device 21 is connected to the port P1, a second input device 22 is connected to the port P2, a relay device 42 is connected to the port P3, a relay device 44 is connected to the port P4, a first output device 36 is connected to the port P5, and a second output device 37 is connected to the port P6. The ports P7 to Pn are, for example, free ports.

[0057] Here, a port connected to a higher-level node is appropriately referred to as an "upper-level port." In this embodiment, ports P1 and P2 are upper-level ports. Also, a port connected to a lower-level node is appropriately referred to as a "lower-level port." In this embodiment, ports P3 to P6 are lower-level ports. That is, relay device 41 has multiple lower-level ports.

[0058] The in-vehicle network of this embodiment is a tree-type network as shown in Fig. 1. For example, the nodes (e.g., relay devices 42 and 43, and first output devices 31, 32, and 33) included in the first network located below the relay device 41, starting from a predetermined first lower port (e.g., port P3) among the multiple lower ports of the relay device 41, are not in common with the nodes (e.g., relay device 44, and first output devices 34 and 35) included in the second network located below the relay device 41, starting from a second lower port (e.g., port P4) different from the first lower port.

[0059] The integrated circuit 70 has a receiving unit 71, a filter unit 72, a relay unit 73, and a transmitting unit 74. The integrated circuit 70 is configured, for example, by a switching integrated circuit, and realizes the functions of the units 71 to 74 based on a program written in advance. The integrated circuit 70 may be configured, for example, by an FPGA (Field Programmable Gate Array).

[0060] The receiver 71 receives a packet from the port 60 and outputs the packet to the filter 72. The filter 72 outputs the packet to a different destination depending on the type of the packet. The filter 72 includes a first filter 721, a second filter 722, and a third filter 723.

[0061] 4 is a diagram showing an example of a packet configuration. In this embodiment, packets flowing within the network include a connection packet PC1, a higher-level packet PC2, a lower-level packet PC3, and other packets PC4.

[0062] The connection packet PC1 is a packet for the talker (devices 21, 22) to collect information on the listener (devices 31 to 37). The connection packet PC1 includes an Ethernet header Fe and a first packet F1. The Ethernet header Fe is a header in which various information related to Ethernet communication is described. The first packet F1 includes a packet F11 and a packet F12. The packet F11 is a packet that complies with, for example, the AVB communication protocol (AVTP: AVB Transport Protocol) in IEEE1722. The packet F12 is a packet that complies with the first protocol or the second protocol, and is stored in the payload of the packet F11. The first packet F1 includes various commands.

[0063] The first protocol is a protocol for managing the connection states of the various devices 21-22, 31-37, and 41-44 (nodes) included in the relay system 10, and is, for example, the AVDECC Connection Management Protocol (ACMP) in IEEE1722.1.

[0064] The second protocol is a protocol for detecting the functions of each of the various devices 21-22, 31-37, and 41-44 (nodes) included in the relay system 10, and is, for example, the AVDECC Enumeration and Control Protocol (AECP) in IEEE1722.1.

[0065] The upper packet PC2 is a packet including surround audio data input to an upper port of a relay device (e.g., relay device 41), and is also called a stream. The upper packet PC2 includes an Ethernet header Fe and a second packet F2. The second packet F2 includes a packet F21 describing the format of the surround audio data, and a packet F22 including the surround audio data.

[0066] Packet F21 is, for example, a packet conforming to AVTP, and stores information such as the data length (payload length) of each sample included in the surround audio data and the number of channels of the surround audio data (format information of the surround audio data).

[0067] Fig. 5 is a diagram showing an example of the contents of packet F22. Packet F22 is the main body (audio payload) of surround audio data. Packet F22 is encapsulated using the AVTP format. In the example of Fig. 5, packet F22 has three samples for each of six channels, and a total of 18 samples are stored in packet F22. In this embodiment, first output device 31 corresponds to channel number 1. Similarly, first output devices 32 to 36 correspond to channel numbers 2 to 6, respectively.

[0068] The lower packet PC3 is a packet including one channel or multiple channels of audio data output from a lower port of a relay device (for example, relay device 41). The lower packet PC3 will be described later.

[0069] Refer to FIG. 4. The other packet PC4 is a packet having a role other than that of the connection packet PC1, the upper packet PC2, and the lower packet PC3. The packet PC4 includes an Ethernet header Fe and a third packet F3. The third packet F3 is a packet in which data (other data) other than that of the first packet F1 and the second packet F2 is stored. For example, the third packet F3 stores a command for the talker (devices 21, 22) to disconnect from the listener (devices 31 to 37). The third packet F3 may also store data related to the vehicle V1 acquired by the second input device 22.

[0070] Please refer to Figure 3. The first filter 721 is a filter that extracts a connection packet PC1 from packets output from the receiving unit 71 to the filter unit 72. The first filter 721 outputs the extracted connection packet PC1 to the relay unit 73, and also copies the extracted connection packet PC1 and outputs it to the acquisition unit 81 described later.

[0071] The second filter 722 is a filter that extracts a superior packet PC2 from among packets output from the receiving unit 71 to the filter unit 72. The second filter 722 outputs the extracted superior packet PC2 to a generating unit 83, which will be described later.

[0072] The third filter 723 is a filter that extracts other packets PC4 from the packets output from the receiving unit 71 to the filter unit 72. The third filter 723 outputs the extracted other packets PC4 to the relay unit 73.

[0073] The relay unit 73 outputs the packet received from the filter unit 72 to the transmission unit 74. The relay unit 73 may perform various processes on the received packet before outputting the packet to the transmission unit 74, or may output the received packet to the transmission unit 74 as is.

[0074] The transmitter 74 transmits a packet received from the relay unit 73 or the arithmetic processing unit 80 to the port unit 60 .

[0075] The arithmetic processing unit 80 includes an acquisition unit 81, a management unit 82, and a generation unit 83. The arithmetic processing unit 80 is configured by, for example, a CPU, and realizes the functions of each unit 81 to 83 by reading computer programs stored in a storage unit (not shown) and executing various arithmetic processing.

[0076] The acquiring unit 81 acquires, for each of a plurality of lower ports, channel information related to channels reproduced in a network located below each of the lower ports based on the connection packet PC1. For example, the acquiring unit 81 extracts information related to talkers (devices 21-22) and listeners (devices 31-37) from the first packet F1 of the connection packet PC1. For example, the acquiring unit 81 extracts information related to which ports P1-Pn the first output devices 31-36, which are destinations of the surround sound data among the listeners, are connected to the relay device 41 and how. The acquiring unit 81 outputs the extracted information to the management unit 82.

[0077] The management unit 82 stores the information extracted by the acquisition unit 81. The management unit 82 has a talker information storage unit 821, a listener information storage unit 822, and a channel information storage unit 823. The talker information storage unit 821 stores information indicating a talker. When the connection packet PC1 is a packet for the first input device 21 to collect information of the first output devices 31 to 36, the talker information storage unit 821 stores information indicating the first input device 21. The information indicating the first input device 21 includes, for example, an identification number of the first input device 21 and a port number (port P1 in this embodiment) through which the first input device 21 connects to the relay device 41.

[0078] The listener information storage unit 822 stores information indicating a listener. When the connection packet PC1 is a packet for the first input device 21 to collect information on the first output devices 31-36, information indicating the first output devices 31-36 is stored in the listener information storage unit 822. The information indicating the first output devices 31-36 includes, for example, the identification numbers of the first output devices 31-36 and port numbers through which the first output devices 31-36 are directly or indirectly connected to the relay device 41. The identification numbers and port numbers are stored in a state associated with each other.

[0079] 1, the first output device 31 is connected to the relay device 41 via the relay devices 42 and 43. Therefore, the identification number of the first output device 31 is stored in the listener information storage unit 822 in a state associated with the port number of port P3 through which the relay device 42 connects to the relay device 41. Similarly, the identification numbers of the first output devices 32 and 33 are associated with the port number of port P3, the identification numbers of the first output devices 34 and 35 are associated with the port number of port P4, and the identification number of the first output device 36 is associated with the port number of port P5, all of which are stored in the listener information storage unit 822.

[0080] As a result, the following information is stored, for example, in a table format, in the listener information storage unit 822. Note that this information is just an example, and the content and format of the information are not particularly limited as long as the information associates the listeners with the ports P1 to Pn.

[0081] (An example of information stored in the listener information storage unit 822) Identification number of the first output device 31: Port number of port P3 Identification number of the first output device 32: Port number of port P3 Identification number of the first output device 33: Port number of port P3 Identification number of the first output device 34: Port number of port P4 Identification number of the first output device 35: Port number of port P4 Identification number of the first output device 36: Port number of port P5

[0082] The information stored in the listener information storage unit 822 is output to a channel information storage unit 823 .

[0083] The channel information storage unit 823 stores channel information on the channels corresponding to each port based on the information indicating the listener output from the listener information storage unit 822. For example, since the first output devices 31, 32, and 33 exist in the network located below the port P3, the port number of the port P3 is associated with the channel numbers 1, 2, and 3 reproduced by the first output devices 31, 32, and 33, and is stored in the channel information storage unit 823. Similarly, the port numbers of the ports P4 and P5 are also associated with the channel numbers reproduced by each listener and are stored.

[0084] As a result, channel information storage unit 823 stores channel information related to channels played in a downstream network starting from a specific downstream port (e.g., port P3). The channel information is stored in a table format of port numbers and channel numbers, for example, as shown below. Note that the channel information is an example, and the content and format of the channel information are not particularly limited as long as the information includes a channel corresponding to each of ports P1 to Pn.

[0085] (An example of channel information stored in the channel information storage unit 823) Port number of port P3: Channel number 1, 2, 3 Port number of port P4: Channel number 4,5 Port number of port P5: Channel number 6

[0086] The channel information stored in the channel information storage unit 823 is output to a later-described construction unit 832 included in the generation unit 83. Note that the channel information storage unit 823 may be omitted, and the information stored in the listener information storage unit 822 may be output directly to the construction unit 832.

[0087] The generating unit 83 reconstructs the upper packet PC2 to generate a lower packet PC3 described later. The generating unit 83 includes an analyzing unit 831 and a constructing unit 832. The analyzing unit 831 analyzes information included in the upper packet PC2 and extracts various information from the upper packet PC2. For example, the analyzing unit 831 decomposes the surround audio data stored in the packet F22 for each channel based on the format information of the surround audio data stored in the packet F21. The analyzing unit 831 outputs the packet F21 and the decomposed surround audio data to the constructing unit 832.

[0088] The construction unit 832 reconstructs the surround audio data for each of the ports P1 to Pn by deleting unnecessary samples from the surround audio data (decomposed packet F22) output from the analysis unit 831 based on the channel information for each of the ports P1 to Pn output from the channel information storage unit 823.

[0089] 6 is a diagram showing packets F23 to F25 for the ports P3 to P5 constructed by the constructing unit 832. The packets F23 to F25 are the main body (audio payload) of the surround audio data. The packet F23 corresponds to the port P3, the packet F24 corresponds to the port P4, and the packet F25 corresponds to the port P5.

[0090] For example, the first output devices 31, 32, and 33 are present downstream of the port P3, and other listeners (devices 34-36) that are destinations of the connection packet PC1 are not present downstream of the port P3. Therefore, the constructing unit 832 extracts only samples of channel numbers 1-3 that are played back in the first output devices 31, 32, and 33 connected to the port P3 from the packet F22 (audio payload) shown in Fig. 5, and constructs the packet F23 shown in Fig. 6.

[0091] Similarly, the first output devices 34 and 35 are present downstream of port P4, but the other listeners (devices 31-33, 36) that are destinations of connection packet PC1 are not present downstream of port P4. Therefore, the construction unit 832 extracts only samples of channel numbers 4 and 5 that are played back in the first output devices 34 and 35 from packet F22, and constructs packet F24. Moreover, since only the first output device 36 is present downstream of port P5, the construction unit 832 extracts only samples of channel number 6 from packet F22, and constructs packet F25.

[0092] As a result, from packet F22 including a total of 18 samples, packet F23 including 9 samples, packet F24 including 6 samples, and packet F25 including 3 samples are constructed. In this manner, based on one packet F22, construction unit 832 constructs a plurality of packets F23 to F25, each of which has fewer samples than packet F22.

[0093] The constructing unit 832 generates a lower-level packet PC3 by combining the constructed packets F23, F24, or F25 with packets Fe and F21. Hereinafter, the lower-level packet PC3 generated by combining packet F23 with packets Fe and F21 will be referred to as a "lower-level packet PC3a." In addition, the lower-level packet PC3 generated by combining packet F24 with packets Fe and F21 will be referred to as a "lower-level packet PC3b," and the lower-level packet PC3 generated by combining packet F25 with packets Fe and F21 will be referred to as a "lower-level packet PC3c." The constructing unit 832 outputs the generated multiple lower-level packets PC3a to PC3c to the transmitting unit 74.

[0094] In this embodiment, at least a part of the functional parts described as the integrated circuit 70 may be realized by the arithmetic processing unit 80. In addition, at least a part of the functional parts described as the arithmetic processing unit 80 may be realized by the integrated circuit 70.

[0095] [Relay method] The relay method according to this embodiment will be described below with reference to FIGS. 1 to 7 as appropriate. Fig. 7 is a sequence diagram showing an example of a relay method according to this embodiment. Fig. 7 representatively shows how data is transmitted from the first input device 21 to the first output devices 34, 36 via the relay devices 41, 44. Data is transmitted from the first input device 21 to the other first output devices 31-33, 35 in the same manner, so a description of data transmission to the first output devices 31-33, 35 will be omitted as appropriate.

[0096] The relay system 10 of this embodiment transmits data in accordance with Ethernet AVB including IEEE1722. The data transmission process is roughly divided into a connection process S100, a stream transmission process S200, and a disconnection process S300. The relay method of this embodiment is started based on, for example, a user's input instruction (for example, pressing a play button).

[0097] Each of the devices 21, 22, 31-37, 41-44 included in the relay system 10 of this embodiment is equipped with a computer including a memory, and an arithmetic processing unit such as a CPU in the computer reads out from the memory and executes a computer program including some or all of the steps of the following flowcharts and sequences. Each of the computer programs of the multiple devices 21, 22, 31-37, 41-44 can be installed from the outside. Each of the computer programs of the multiple devices 21, 22, 31-37, 41-44 is distributed in a state of being stored in a recording medium.

[0098] First, a connection step S100 is executed. The connection step S100 is a step of collecting information on all listeners (devices 31 to 37) and establishing connections between the first input device 21 and the listeners before the first input device 21 transmits a higher-level packet PC2 (stream). The connection step S100 is executed based on the ACMP and AECP of IEEE1722.1.

[0099] In the connection step S100, the first input device 21 first generates a connection packet PC1 for requesting information about the listener (step S101), and transmits the connection packet PC1 to the relay device 41 (step S102). The connection packet PC1 transmitted to the listener is also called an advertisement. The relay device 41 transfers the transmitted connection packet PC1 to the relay device 44 and the first output device 36 (steps S103 and S104).

[0100] 3, in the relay device 41, a connection packet PC1 input to port P1 is output from ports P4 and P5 via the receiving unit 71, the first filter 721, the relay unit 73, and the transmitting unit 74. The connection packet PC1 output from port P4 is transmitted to the relay device 44 (step S103), and the connection packet PC1 output from port P5 is transmitted to the first output device 36 (step S104).

[0101] The relay device 44 transfers the transmitted connection packet PC1 to the first output device 34 (step S105). In the relay device 44, similarly to the relay device 41, the input connection packet PC1 is output to the port unit 60 via the receiving unit 71, the first filter 721, the relay unit 73, and the transmitting unit 74.

[0102] Next, the relay device 41 acquires information about the talker based on the connection packet PC1, and stores the information in the talker information storage unit 821 (step S106). Specifically, the connection packet PC1 input to the first filter 721 in step S103 is copied and output to the acquisition unit 81. Then, the acquisition unit 81 extracts information about the talker from the connection packet PC1 (for example, the identification number of the first input device 21 and the port number of the port P1 through which the first input device 21 connects to the relay device 41), and stores the information in the talker information storage unit 821.

[0103] Similarly, the relay device 44 also acquires information about the talker based on the connection packet PC1 input to the first filter 721 in step S105, and stores the information in the talker information storage unit 821 of the relay device 44 (step S107).

[0104] When the first output device 34 receives the connection packet PC1 from the relay device 44, it generates a connection packet PC1 for transmitting its own information to the first input device 21 (step S108) and transmits the connection packet PC1 to the relay device 44 (step S109). The connection packet PC1 transmitted to the talker is also called ready. The transmitted connection packet PC1 is transferred from the relay device 44 to the relay device 41 (step S110), and is then transferred from the relay device 41 to the first input device 21 (step S111).

[0105] For example, in step S111, in the relay device 41, a connection packet PC1 input to the port P4 passes through the receiver 71, the first filter 721, the relay unit 73, and the transmitter 74, and is output to the port P1.

[0106] When the first output device 36 receives the connection packet PC1 from the relay device 41, it generates a connection packet PC1 for transmitting its own information to the first input device 21 (step S112) and transmits the connection packet PC1 to the relay device 41 (step S113). The transmitted connection packet PC1 is transferred from the relay device 41 to the first input device 21 (step S114).

[0107] Next, the relay device 41 acquires information about the listener based on the connection packet PC1, and stores the information in the listener information storage unit 822 (step S115). Specifically, the connection packet PC1 input to the first filter 721 in steps S111 and S114 is copied and output to the acquisition unit 81. Then, the acquisition unit 81 extracts information about the listener from the connection packet PC1 (for example, the identification numbers of the first output devices 34 and 36, and the port numbers of the ports P4 and P5 through which the first output devices 34 and 36 are indirectly or directly connected to the relay device 41), and stores the information in the listener information storage unit 822.

[0108] Similarly, the relay device 44 also acquires information about the listener based on the connection packet PC1 input in step S110, and stores the information in the listener information storage unit 822 of the relay device 44 (step S116).

[0109] Although a detailed description will be omitted, since the relay device 41 is indirectly connected to the first output devices 31-33, and 35, the relay device 41 also collects information on the first output devices 31-33, and 35 in step S115, and this information is stored in the listener information storage unit 822. Similarly, the relay device 44 also collects information on the first output device 35 in step S116, and this information is stored in the listener information storage unit 822.

[0110] In this manner, the connection packet PC1 is transmitted and received between the first input device 21 and the first output devices 31-36, thereby establishing a connection between the first input device 21 and the first output devices 31-36. This ends the connection step S100. The connection step S100 is thereafter repeated periodically. This maintains the connection state between the first input device 21 and the first output devices 31-36.

[0111] Then, a stream transmission step S200 is executed. The stream transmission step S200 is a step in which the first input device 21 transmits the upper layer packet PC2. The stream transmission step S200 is executed based on the AVTP of IEEE1722.

[0112] In the stream transmission step S200, the first input device 21 first generates a superior packet PC2 including surround audio data (step S201) and transmits it to the relay device 41 (step S202). The superior packet PC2 transmitted to the listener is also called a stream.

[0113] The relay device 41 disassembles and reassembles the upper layer packet PC2 received in step S202 to generate different lower layer packets PC3a to PC3c for each output port (step S203). Specifically, as shown in Fig. 3, in the relay device 41, the upper layer packet PC2 input to the port P1 is input to the analyzer 831 included in the generator 83 via the receiver 71 and the second filter 722.

[0114] The analyzer 831 disassembles the surround audio data stored in the packet F22 of the superior packet PC2 for each channel based on the format information of the surround audio data stored in the packet F21 of the superior packet PC2. The analyzer 831 outputs the packet F21 and the disassembled surround audio data to the constructor 832.

[0115] Next, the constructing unit 832 constructs a packet F24 (FIG. 6) to be output from port P4 by deleting samples of channel numbers 1 to 3, and 6 that are not included in the channel information from the surround audio data (decomposed packet F22) output from the analyzing unit 831 based on the channel information for port P4 (information on channels reproduced in a network located downstream of port P4) output from the channel information storage unit 823. Then, the constructing unit 832 combines the constructed packet F24 with packet F21 to generate a lower-level packet PC3b.

[0116] Similarly, the constructing unit 832 constructs a packet F25 (FIG. 6) to be output from port P5 by deleting samples of channel numbers 1 to 5 from packet F22 based on the channel information for port P5 output from the channel information storage unit 823. Then, the constructing unit 832 combines the constructed packet F25 with packet F21 to generate lower-level packet PC3c.

[0117] Next, the relay device 41 transmits the constructed lower-level packet PC3b to the relay device 44 (step S204). Specifically, the lower-level packet PC3b passes through the constructing unit 832 and the transmitting unit 74 of the relay device 41 and is transmitted from the port P4 to the relay device 44. The relay device 41 also transmits the constructed lower-level packet PC3c to the first output device 36 (step S205). Specifically, the lower-level packet PC3c passes through the constructing unit 832 and the transmitting unit 74 of the relay device 41 and is transmitted from the port P5 to the first output device 36.

[0118] The relay device 44 further decomposes and reconstructs the lower-level packet PC3b received in step S204 to generate a different lower-level packet PC3d for each output port (step S206). Specifically, the lower-level packet PC3b input to the relay device 44 is input to the analysis unit 831 via the receiving unit 71 and the second filter 722 of the relay device 44. The analysis unit 831 decomposes the surround sound data stored in the packet F22 of the lower-level packet PC3b for each channel, and outputs the data to the construction unit 832. Although the names have not been changed for convenience in the above explanation, when focusing on the relay device 44, the lower-level packet PC3b is the "upper-level packet" input from the upper port.

[0119] Here, packet F24 of lower-level packet PC3b contains only samples of channel numbers 4 and 5. The construction unit 832 of the relay device 44 deletes the sample of channel number 5 from packet F24 based on the channel information for each port output from the channel information storage unit 823. As a result, the construction unit 832 constructs a packet (a packet including only a sample of channel number 4) to be output to the first output device 34. The construction unit 832 then combines the constructed packet with packet F21 to generate lower-level packet PC3d.

[0120] Next, the relay device 44 transmits the constructed lower-level packet PC3d to the first output device 34 (step S207).

[0121] The first output device 34 reproduces the audio data of channel number 4 based on the lower-level packet PC3d received in step S207 (step S208). The first output device 36 reproduces the audio data of channel number 6 based on the lower-level packet PC3c received in step S205 (step S209).

[0122] This completes the stream transmission step S200. The stream transmission step S200 is periodically repeated thereafter. As a result, the first input device 21 sequentially transmits the superior packets PC2 including the surround audio data, and the first output devices 31-36 continue to play back the audio data.

[0123] Finally, a disconnection step S300 is executed. The disconnection step S300 is a step of disconnecting the first input device 21 from the first output devices 31 to 36. The disconnection step S300 is executed based on the ACMP of IEEE172.1.

[0124] In the disconnection step S300, first, the first input device 21 generates a packet PC4 (FIG. 4) including a disconnection command in a third packet F3 (step S301), and transmits the packet PC4 to the relay device 41 (step S302). The relay device 41 transfers the transmitted packet PC4 to the relay device 44 and the first output device 36 (steps S303, S304).

[0125] Specifically, in the relay device 41, a packet PC4 input to port P1 is output from ports P4 and P5 via the receiving unit 71, the third filter 723, the relay unit 73, and the transmitting unit 74. The packet PC4 output from port P4 is transmitted to the relay device 44 (step S303), and the packet PC4 output from port P5 is transmitted to the first output device 36 (step S304). The relay device 44 transfers the transmitted packet PC4 to the first output device 34 (step S305).

[0126] The first output device 34 disconnects the connection with the first input device 21 based on the disconnect command included in the packet PC4, and generates a packet PC4 including in a third packet F3 a command for notifying that the disconnection has been completed (step S306). Then, the first output device 34 transmits the generated packet PC4 to the relay device 44 (step S307). Thereafter, the relay device 44 transfers the packet PC4 to the relay device 41 (step S308), and the relay device 41 transfers the packet PC4 to the first input device 21 (step S309).

[0127] Similarly, the first output device 36 disconnects the connection with the first input device 21 based on the packet PC4, and generates a packet PC4 including a command for notifying that the disconnection has been completed (step S310). Then, the first output device 36 transmits the generated packet PC4 to the relay device 41 (step S311). Thereafter, the relay device 41 transfers the packet PC4 to the first input device 21 (step S312). With the above, the disconnection step S300 is completed.

[0128] Effects of this embodiment The relay device 41 according to this embodiment is a relay device that relays a packet including voice data from the upper side to the lower side of an in-vehicle network, and includes an upper port P1 to which an upper packet PC2 including voice data of multiple channels is input, a plurality of lower ports P3 to P5 that output lower packets PC3a to PC3c including voice data of one channel or multiple channels, and a generation unit 83 that reconstructs the upper packet PC2 to generate the lower packets PC3a to PC3c, and the plurality of lower ports P3 to P5 are connected to a first lower port (e.g., P4), , and a second lower port (e.g., P3, P5), where the first lower port is the origin of a first network located below the relay device 41, and the second lower port is the origin of a second network located below the relay device and which does not share a node with the first network, and the generation unit 83 constructs audio data to be included in the lower packet PC3b output from the first lower port by deleting audio data of channels (e.g., channel numbers 1 to 3, 6) played in the second network from the audio data included in the upper packet PC2.

[0129] The lower packet PC3b generated by the generation unit 83 does not include audio data of channel numbers 1 to 3, and 6 reproduced by the first output devices 31 to 33, and 36 that are not present in the network located below the port P4, and therefore has a smaller amount of data than the upper packet PC2. Therefore, the bandwidth required to transmit the lower packet PC3b from the relay device 41 to the relay device 44 is smaller than the bandwidth required to transmit the upper packet PC2 as is.

[0130] For example, under certain conditions, when the bandwidth required by upper packet PC2 (channel 6) is 11.2 Mbps, the bandwidth required by lower packet PC3b (channel 2) is 6.6 Mbps, and the bandwidth required by lower packet PC3d (channel 1) is 5.7 Mbps.

[0131] As a result, the bandwidth required for transmitting packets is reduced, making it easier to secure the bandwidth for transmitting packets, and audio data including multiple channels can be transmitted more reliably.

[0132] Furthermore, the generation unit 83 of this embodiment constructs audio data to be included in the lower packet PC3c output from the second lower port (e.g., P5) by deleting audio data of a channel (e.g., channel numbers 4 and 5) output in the first network from the audio data included in the upper packet PC2.

[0133] The generation unit 83 generates lower packets PC3a, PC3b, and PC3c having a smaller amount of data than the upper packet PC2 for each of the multiple lower ports P3, P4, and P5. This makes it possible to reduce the bandwidth required to transmit packets in each of the multiple networks located below the relay device 41, and to more reliably transmit audio data including multiple channels.

[0134] Moreover, the relay device 41 according to this embodiment includes a relay unit 73 that relays a connection packet PC1 transmitted from the first output devices 31-36 to the first input device 21 before the upper packet PC2 is input to the upper port P1, and an acquisition unit 81 that acquires channel information related to a channel being played in a network located below a predetermined lower port (e.g., port P4) based on the connection packet PC1. The connection packet PC1 is a packet that allows the first input device 21 to collect information related to the first output devices 31-36, and the generation unit 83 generates a lower packet PC3b based on the channel information acquired by the acquisition unit 81.

[0135] The connection packet PC1 is a packet transmitted to establish a connection between the first input device 21 and the first output devices 31 to 36. The relay device 41 knows the channels to be played in the network located below the lower ports P3, P4, and P5 based on such existing packets, so there is no need to increase extra packets. In other words, it is possible to more reliably transmit audio data including multiple channels while suppressing an increase in the burden of transmitting and receiving packets.

[0136] The connection packet PC1 includes a packet F11 conforming to the device connection state management protocol in IEEE 1722.1 and a packet F12 conforming to the device function detection control protocol in IEEE 1722.1. These packets F11 and F12 make it easy to know the connection state between the first output devices 31-36 and the relay device 41 and the channel numbers corresponding to the first output devices 31-36, respectively.

[0137] The relay device 41 according to this embodiment further includes a filter unit 72 that outputs a connection packet PC1 input from the lower ports P3 to P5 to the relay unit 73 and the acquisition unit 81, and outputs an upper packet PC2 input from the upper port P1 to the generation unit 83. In addition, the filter unit 72 outputs the other packet PC4 to the relay unit 73.

[0138] With this configuration, the relay device 41 has the function of reconstructing the upper packet PC2 including the audio data of multiple channels into the lower packets PC3a to PC3c, while relaying the other packet, the packet PC4, as it is. Therefore, the relay device 41 can be suitably used for an in-vehicle network in which audio data and other data are mixed.

[0139] <<Variation>> Modifications of the embodiment will be described below. In the modifications, the same components as those in the embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

[0140] <<Modification 1 of lower packet>> The relay device 41 in the above embodiment generates lower level packets PC3a, PC3b, and PC3c for each of the lower level ports P3, P4, and P5 by deleting audio data of a predetermined channel from the upper level packet PC2. However, it is not essential to generate lower level packets corresponding to all lower levels, and the upper level packet PC2 may be output as a lower level packet as it is in at least one lower level port.

[0141] For example, the relay device 41 may generate a lower packet PC3a to be output from the lower port P3 by deleting the audio data of channel numbers 4, 5, and 6 from the upper packet PC2, while outputting the upper packet PC2 as is from the lower ports P4 and P5. Even in such a configuration, the lower packet PC3a, which has a smaller amount of data than the upper packet PC2, is transmitted in the network located below the lower port PC3, so that the required bandwidth can be reduced.

[0142] <<Modification 2 of lower packet>> The relay device 41 in the above embodiment generates a lower packet PC3a by deleting all audio data of channel numbers 4, 5, and 6, which are reproduced in a network that is not located below the lower port P3, from the upper packet PC2. That is, the relay device 41 generates a lower packet PC3a from the upper packet PC2, leaving only audio data of channel numbers 1, 2, and 3, which are reproduced in a network located below the lower port P3.

[0143] However, the relay device 41 need only delete at least a part of the audio data of channel numbers 4, 5, and 6 that is reproduced in a network that is not located below the lower port P3 from the upper packet PC2, and does not have to delete all of it. For example, the relay device 41 may delete only the audio data of channel number 6 from the upper packet PC2, and output a lower packet including the audio data of channel numbers 1 to 5 from the lower port P3.

[0144] Even in this configuration, the lower packet has a smaller amount of data than the higher packet PC2 by the amount of audio data of channel number 6 deleted, so that the bandwidth required for transmitting the packets can be reduced.

[0145] 《Addendum》 In addition, at least some of the above-mentioned embodiments may be arbitrarily combined with each other. In addition, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0146] 10 Relay System 21 First input device 22 Second input device 31 1st output device 32 1st output device 33 1st output device 34 1st output device 35 1st output device 36 1st output device 37 Secondary Output Device 41 Relay Device 42 Relay Device 43 Relay Device 44 Relay Device 50 Communication Line 60 Port section 70 Integrated Circuits 71 Receiving section 72 Filter section 721 First Filter 722 Second Filter 723 3rd Filter 73 Relay Section 74 Transmitter 80 Processing unit 81 Acquisition Department 82 Management Department 821 Talker information storage unit 822 Listener information storage section 823 Channel information storage section 83 Generation part 831 Analysis Department 832 Construction Department 9. Relay System 910 Input Device 921 Output Device 922 Output Device 923 Output Device 924 Output Device 925 Output Device 926 Output Device 931 Repeater 932 Repeater 933 Repeater 934 Repeater 94 Communication Line V1 Vehicle S1 Driver's seat S2 passenger seat S3 back seat P1 port (upper port) P2 port (upper port) P3 port (lower port) P4 port (lower port) P5 port (lower port) P6 port (lower port) P7 port (free port) Pn port (free port) PC1 connection packets PC2 Upper packet PC3 Lower Packet PC3a Lower Packet PC3b Lower Packet PC3c Lower Packet PC3d Lower Packet PC4 Packet F1 1st packet F11 Packet F12 Packet F2 2nd packet F21 Packet F22 Packet F23 Packet F24 Packet F25 Packet F3 3rd packet Fe Ethernet Header

Claims

1. A relay device that relays a packet including voice data from a higher-level side to a lower-level side of an in-vehicle network, an upper port to which an upper packet including audio data of multiple channels is input; a plurality of lower-level ports each outputting a lower-level packet including one or more channels of audio data; a generation unit that reconstructs the upper layer packet to generate the lower layer packet; an acquisition unit that acquires channel information related to a channel being played in at least one of the first network and the second network based on a connection packet transmitted from a lower node to a higher node; Equipped with the plurality of downstream ports include a first downstream port and a second downstream port; the first downstream port is a starting point of the first network located downstream of the relay device, the second downstream port is a starting point of the second network that is located below the relay device and does not share a node with the first network; the generation unit constructs audio data to be included in the lower packet to be output from the first lower port by deleting audio data of a channel reproduced in the second network from the audio data included in the upper packet based on the channel information; The connection packet is a packet for a higher-level node to collect information about a lower-level node. Relay device.

2. the generation unit constructs audio data to be included in the lower packet to be output from the second lower port by deleting audio data of a channel output in the first network from the audio data included in the upper packet. The relay device according to claim 1 .

3. a relay unit that relays a connection packet transmitted from a lower node to an upper node before the upper packet is input to the upper port; The relay device according to claim 1 or 2.

4. The connection packet includes: A packet conforming to a device connection state management protocol in IEEE 1722.1; A packet conforming to the Device Capability Discovery and Control Protocol in IEEE 1722.1; The relay device according to claim 3 .

5. a filter unit that outputs the connection packet input from the lower port to the relay unit and the acquisition unit, and outputs the upper packet input from the upper port to the generation unit, The relay device according to claim 3 or 4.

6. the filter unit outputs packets other than the upper layer packet and the connection packet to the relay unit. The relay device according to claim 5 .

7. The packets other than the upper packet and the connection packet include data detected by an in-vehicle sensor device. The relay device according to claim 6.

8. A relay device according to any one of claims 1 to 7, an upper node that outputs the upper packet; a lower node for reproducing the audio data included in the lower packet; A relay system comprising:

9. A relay method in which a relay device relays a packet including voice data from a higher-level side to a lower-level side of an in-vehicle network, comprising: The relay device is an upper port to which an upper packet including audio data of multiple channels is input; a plurality of lower-level ports each outputting a lower-level packet including one or more channels of audio data; Equipped with the plurality of downstream ports include a first downstream port and a second downstream port; the first downstream port is a starting point of a first network located downstream of the relay device; the second downstream port is a starting point of a second network that is located below the relay device and does not share a node with the first network; The relay method includes: reconstructing the upper layer packet to generate the lower layer packet; obtaining channel information related to a channel being played in at least one of the first network and the second network based on a connection packet transmitted from a lower node to a higher node; Equipped with the generating step includes a step of constructing audio data to be included in the lower packet to be output from the first lower port by deleting audio data of a channel reproduced in the second network from the audio data included in the upper packet based on the channel information; The connection packet is a packet for a higher-level node to collect information about a lower-level node. Relay method.

10. A computer program for causing a relay device to relay a packet including voice data from a higher-level side to a lower-level side of an in-vehicle network, The relay device is an upper port to which an upper packet including audio data of multiple channels is input; a plurality of lower-level ports each outputting a lower-level packet including one or more channels of audio data; Equipped with the plurality of downstream ports include a first downstream port and a second downstream port; the first downstream port is a starting point of a first network located downstream of the relay device; the second downstream port is a starting point of a second network that is located below the relay device and does not share a node with the first network; The computer program includes: reconstructing the upper layer packet to generate the lower layer packet; obtaining channel information related to a channel being played in at least one of the first network and the second network based on a connection packet transmitted from a lower node to a higher node; Run the command, the generating step includes a step of constructing audio data to be included in the lower packet to be output from the first lower port by deleting audio data of a channel reproduced in the second network from the audio data included in the upper packet based on the channel information; The connection packet is a packet for a higher-level node to collect information about a lower-level node. Computer program.

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