Patent Application
20240137332
The methods and devices described herein relate to methods and devices for transmitting a signal from a first electronic component of a vehicle to at least one second electronic component of the vehicle. In particular, switching between a low-level protocol and a packet-switching protocol is described.
Many applications, in particular in the automotive field, increasingly need bandwidth in the communication networks to transmit, for example, images, audio streams or video streams.
In the automotive field, electronic components onboard vehicles, such as, for example, ECUs (Electronic Control Units), or on an onboard computer, communicate with one another by frames of low-level network protocols such as the Controller Area Network (CAN). This protocol made it possible to reduce the number of wires used for the transmissions within the vehicle by multiplexing the data. There are different versions of the protocol, aimed at increasing its bandwidth. However, the various evolutions of the CAN protocol do not lead to sufficient bandwidths. Furthermore, the protocol steps for transmission/reception of CAN protocol frames in particular involve error detection and error signaling mechanisms which consume computing resources, in particular for the components in charge of low layers.
Also, other protocols such as in particular a packet-switching protocol like Ethernet have been used in vehicles. However, these packet-switching protocols and more particularly the Ethernet protocol, having been designed for exchanges between computers, involve high-level processing (application layers) that is difficult to implement on all the low-level computers of a vehicle.
There is therefore a need for a protocol capable of managing large bandwidths while being compatible with a wide variety of electronic components of the vehicle.
One object is to transmit a frame of a low-level network between several electronic components of a vehicle via transceivers of a packet-switching protocol.
According to a first aspect, a method for transmitting a signal from a first electronic component of a vehicle to at least one second electronic component of the vehicle, said signal being formed from a frame of a low-level network protocol and being transmitted via transceivers of a packet-switching protocol, comprises the following steps:
According to one embodiment, the frame is redirected to an output port whose number is stored in an addressing table in association with a destination address identical to the destination address extracted from the frame.
According to one variant, the destination address extracted from the frame is stored in the addressing table in association with the number of the input port if this association is not already stored in the addressing table.
According to one embodiment, the frame is redirected to an output port whose number is stored in the addressing table in association with a destination address of the packet-switching protocol obtained from a destination address identical to a destination address extracted from the frame.
According to one variant, the destination address of the packet-switching protocol is stored in the addressing table in association with the number of the input port if this association is not already stored in the addressing table.
According to one embodiment, the method further comprises a step of extracting a source address of the frame and storing said source address in an addressing table in association with the number of the input port of the network switch on which the frame is received.
According to one embodiment, the method further comprises a step of extracting a source address of the frame and storing a source address of the packet-switching protocol obtained from said extracted source address, in an addressing table in association with the number of the input port of the network switch on which the frame is received.
According to one embodiment, the frame being a frame of the low-level protocol or a frame of the packet-switching protocol, information is stored to identify whether an input port of the network switch accepts frames of low-level protocol or frames of the packet-switching protocol.
A second aspect relates to a network switch comprising a memory unit associated with at least one processor configured to implement the steps of the method according to the first aspect.
A third aspect relates to a vehicle, for example a motor vehicle, comprising a device as described above according to the second aspect.
A fourth aspect also relates to a computer program that comprises instructions suitable for executing the steps of the method, according to the first aspect, particularly when said computer program is executed by at least one processor.
Such a computer program can use any programming language, and be in the form of a source code, an object code, or an intermediate code between a source code and an object code, such as in a partially compiled form, or in any other desirable form.
A fifth aspect relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for the execution of the steps of the method according to the first aspect.
On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a ROM memory of the microelectronic circuit type, or a magnetic recording means or a hard drive.
On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal able to be conveyed via an electrical or optical cable, by conventional or microwave radio, or by self-directional laser beam or by other means. The computer program can in particular be downloaded over a network of the Internet type.
Alternatively, the recording medium can be an integrated circuit wherein the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the method in question.
Other features and advantages will become apparent from the description of the non-limiting embodiments below, with reference to the appended
A method and a device for transmitting a signal by a first electronic component of a vehicle intended for at least one second electronic component of the vehicle will now be described in reference to
The transmission, by an electronic component of a vehicle, of a frame T of a low-level network intended for several other electronic components of this vehicle configured to exchange signals through the transceivers according to a packet-switching protocol, uses a network switch supporting the routing of frames between input ports and output ports of that switch on the basis of an addressing table.
The system 1 comprises a first electronic component 110, at least one second electronic component 111 to 11M and a network switch 12.
The network switch 12 comprises input ports 1211 to 121N, output ports 1231 to 123M, an addressing table 122, low-level protocol frame controllers 1221 to 122N and 1241 to 124N, one (or several) processors or microprocessors 125 and a memory 126.
The input ports 1211 to 121N and output ports 1231 to 123M of the network switch 12 are associated with transceivers (not shown) of a packet-switching protocol to be able to receive/transmit signals compliant with the physical layer of this packet-switching protocol. In addition, each input port 1211 to 121N is associated with a controller 1221 to 122N and each output port 1231 to 123M is associated with a controller 1241 to 124M which generates a signal from a frame of a low-level protocol so that this frame can be sent via the transceiver of one of the output ports 1231 to 123M.
Each electronic component 11m (m=1 to M) comprises a port 112m associated with a transceiver (not shown) of the packet-switching protocol, and a controller 111m of the low-level protocol frame. Each electronic component 11m (m=1 to M) is connected to an output port 1231 to 123M of the network switch 12.
Controllers 111m (m=1 to M) are provided to retrieve frames T from signals received via the transceivers of ports 112m (m=1 to M).
The electronic component 110 comprises a port 1120 and a controller 1110 provided to generate a signal from a frame T of the low-level protocol so that this frame T can be sent via the transceiver of the port 1120.
A frame routing mechanism is implemented by the processor 125, the memory 126 and the addressing table 122. This mechanism is similar to that implemented by packet-switching protocol network switches.
In this type of packet-switching network switch, this mechanism uses an addressing table that stores source addresses of the packet-switching protocol, conventionally called the MAC source address, and destination addresses of the packet-switching protocol, conventionally called MAC destination addresses, associated with input and output port numbers of the network switch. Thus, following the receipt of a frame of the packet-switching protocol on an input port, a MAC destination address is extracted from the header of the received frame. This MAC destination address is compared to a MAC destination address of the addressing table that can then associate this MAC destination address with one or more of the output ports. The received frame is then redirected to this or these output port(s). If no MAC destination address is extracted from the header of the received frame then the received frame is redirected to all of the output ports. If the extracted MAC destination address is not stored in the addressing table, then it is stored in the addressing table in association with the number of the output port on which a recipient electronic component identified by this MAC destination address is connected. A MAC source address is also extracted from the header of the received frame and stored in the addressing table in association with the number of the input port on which the frame was received (if this MAC source address associated with this input port is not already stored in the addressing table). Thus, the addressing table can store a MAC source address of an electronic component transmitting a frame of the packet-switching protocol and connected to an input port, and a MAC destination address of an electronic component receiving a frame of the packet-switching protocol and connected to an output port, so that the frame received by the network switch is redirected to the destination electronic component.
However, the low-level protocol frame T is not a frame of a packet-switching protocol and the operation of the network switch must be adapted so that the low-level protocol frames T are redirected to output ports of that network switch.
In a first operation, a signal is generated from a low-level protocol frame T by the controller 1110 of the electronic component 110. The signal is then sent via the transceiver of the port 1120 and received via the transceiver of an input port, for example the port 1211 of the network switch 12.
In a second operation, the frame T is then retrieved from the signal received by the controller 1221 and this frame T is redirected to at least one controller 124m and an associated output port 123m on the basis of at least one destination address extracted from this frame T.
In a third operation, a signal is generated from the frame T by the controller 124m associated with the output port 123m. The signal is then sent to the recipient electronic component identified by the destination address extracted via the output port of the network switch 12 to which this electronic component is connected, and received on an input port, for example the port 1121 of the recipient electronic component, in this case the electronic component 111 via the transceivers associated with those ports.
According to one embodiment of this first operation, the frame is redirected to an output port whose number is stored in the addressing table 122 in association with a destination address identical to the destination address extracted from the frame T.
According to one variant, the destination address extracted from the frame T is stored in the addressing table 122 in association with the number of the input port if this association is not already stored in the addressing table 122.
According to this embodiment, the addressing table stores addresses of the low-level protocol thus making it possible to implement the frame routing mechanism on the basis of the address of the low-level protocol.
According to one embodiment of this first operation, the frame T is redirected to an output port whose number is stored in the addressing table 122 in association with a MAC destination address of the packet-switching protocol obtained from a destination address identical to the destination address extracted from the frame T.
According to one variant, the MAC destination address is stored in the addressing table 12 in association with the number of the input port if this association is not already stored in the addressing table 122.
According to this embodiment, the addressing table stores addresses of the packet-switching protocol thus making it possible to implement the frame routing mechanism on the basis of the address of the packet-switching protocol.
In a fourth operation (optional), a source address of the low-level protocol is extracted from the frame T.
According to one variant, the extracted source address is stored in the addressing table 122 in association with the number of the input port if this association is not already stored in the addressing table 122.
According to one variant, a MAC source address is obtained from this extracted source address.
According to one variant, the MAC source address is stored in the addressing table 122 in association with the number of the input port if this association is not already stored in the addressing table 122.
Thus, the addressing table 122 can associate a source and/or destination address of either the low-level protocol or the packet-switching protocol with each of the input and output ports of the network switch so that electronic components connected to these ports can exchange low-level protocol frames T.
According to one embodiment, the low-level protocol is of the CAN XL type in accordance with the CiA 610-1 and CiA 610-3 specifications and the packet-switching protocol is of the Ethernet type (standard 802), that is a protocol operating with 100Base-T1 Ethernet transceivers.
The frame T of a CAN XL network protocol comprises seven fields as shown in
Among these fields, the source and destination addresses are expressed in 6 bytes.
According to this embodiment, the MAC addresses of the Ethernet type are expressed in 6 bytes and the source or destination addresses of the frame T of the CAN XL protocol are expressed in 2 bytes.
In the case where the addressing table 122 stores MAC addresses, each stored MAC address is then entered from the 2 bytes of an address extracted from the frame T which are completed by 2 padding bytes.
The network switch 12 can then operate as an Ethernet network switch implementing the mechanism for redirecting the frames T of the low-level protocol on the basis of an Ethernet type MAC address.
The network switch 12, operating on the basis of the MAC address or low-level protocol addresses, can also implement other features conventionally used on incoming Ethernet frames. For example, one of these features is the management of the VLANs (Virtual Local Area Network) based on a VID field of the Ethernet protocol expressed in 12 bits.
In a fifth operation (optional), for the network switch 12 to be able to implement this management of the VLANs, the first eight bits of the VID field are populated by a VCID field extracted from the frame T of the low-level protocol and completed by four padding bits.
In a sixth operation (optional), certain frames or VLANs may be blocked by implementing a firewall feature.
According to one variant, the frame T being a frame of the low-level protocol or a frame of the packet-switching protocol, information INF is stored to identify whether an input port 121n or output port 123m of the network switch accepts frames of the low-level protocol or frames of the packet-switching protocol.
The choice of using addressing tables storing either low-level protocol addresses or MAC addresses can depend on the type of frames received on the input and/or output ports.
The elements of the network switch 12, individually or in combination, can be integrated into a single integrated circuit, in several integrated circuits, and/or in discrete components.
The network switch 12 can be made in the form of electronic circuits or software (or computer) modules or a combination of electronic circuits and software modules.
The controllers 122n (n=1 to N) and/or the processor(s) 125 is (are) configured to execute instructions for performing the operations of
The computer code comprising the instructions of the method of
In a first step 41, a signal is generated from a low-level protocol frame T and received on a physical input port of the network switch 12.
In a second step 42, the frame T, extracted from the received signal, is redirected to an output port of the network switch 12 on the basis of at least one destination address extracted from this frame T.
In a third step 43, a signal is generated from the frame T and transmitted to the electronic component identified by the destination address extracted via said output port of the network switch 12 to which this electronic component is connected.
In a fourth step 44 (optional), a source address is extracted from the frame T and stored in the addressing table 122 in association with the number of the input port of the network switch on which the frame T is received, if this association is not already stored in the addressing table 122.
In a fifth step 45 (optional), the frame T is adapted to populate the VID field of the Ethernet protocol with the 8 bits of the VCID field of the frame of the CAN XL protocol completed by 4 padding bits.
In a sixth operation 46 (optional), certain frames or VLANs may be blocked by implementing a firewall feature.
According to a variant embodiment, the variants and examples of the operations described in relation to
Of course, the devices and methods described are not limited to the embodiments described above but extends to a method for transmission of a signal from a first electronic component of a vehicle to at least one second electronic component of the vehicle that includes secondary steps without departing from the scope of the description. The same applies to a device configured to implement such a method.
The described methods and devices also relate to a vehicle, for example a motor vehicle, comprising a system according to
| Number | Date | Country | Kind |
|---|---|---|---|
| FR2102855 | Mar 2021 | FR | national |
This application is the US National Stage under 35 USC § 371 of International Application No. PCT/FR2022/050261, filed Feb. 14, 2022, which claims the priority of French application 2102855 filed on Mar. 23, 2021, the content (text, drawings and claims) of both said applications being incorporated by reference herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2022/050261 | 2/14/2022 | WO |
