CN116938494A

CN116938494A - Communication method and communication device

Info

Publication number: CN116938494A
Application number: CN202210361525.2A
Authority: CN
Inventors: 张静铖; 查敏
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-04-07
Filing date: 2022-04-07
Publication date: 2023-10-24

Abstract

The embodiment of the application provides a communication method and a communication device, which are used for improving the bearing efficiency of effective data in a message to improve the communication efficiency while saving the cost by avoiding the mode of sending a preamble of the message and a source MAC address of the message in the transmission process of an Ethernet message. In the method, a first node determines a first message, wherein the first message comprises synchronous signaling, and the synchronous signaling is used for determining a preamble of the first message; the first node sends the first message, and a current identifier (current ID) of a physical layer collision avoidance mechanism (physical layer collision avoidance, PLCA) corresponding to the first message is used to determine a source MAC address of the first message.

Description

Communication method and communication device

Technical Field

The present application relates to the field of ethernet communications, and in particular, to a communication method and a communication device.

Background

Ethernet (Ethernet) is a currently commonly used computer local area network technology. Among them, related standards of the 802.1 and IEEE 802.3 standard ethernet (standard ethernet, stdE) defined by the institute of electrical and electronics engineers (institute of electrical and electronics engineers, IEEE) are widely cited in the industry.

Currently, in a data communication process based on an ethernet technology, effective data sent by a communication node is carried in a packet to be transmitted, and the effective data may also be referred to as application data or effective application data. The payload data includes at least a payload, and the packet needs to carry other data in addition to the payload data, so that a receiver of the packet may parse the packet, where the other data may include a source medium access control (media access control, MAC) address field of a source address, a preamble field, and so on.

However, in the implementation process, due to the existence of the other data, the carrying efficiency of the effective data in the transmission process of the ethernet message is low, which affects the communication efficiency.

Therefore, how to improve the bearing efficiency of the effective data to improve the communication efficiency in the transmission process of the ethernet message is a technical problem to be solved.

Disclosure of Invention

The first aspect of the present application provides a communication method, which is performed by a first node, or by a part of components (such as a processor, a chip or a system-on-chip, etc.) in the first node, or by a logic module or software capable of implementing all or part of the functions of the first node. In the first aspect and its possible implementation manner, the communication method is described by using the first node as an example, where the first node may be a router, a switch, a virtual machine, or a device such as an on-board communication node (e.g. a camera, a sensor, a controller, etc.). In the method, a first node determines a first message, wherein the first message comprises synchronous signaling, and the synchronous signaling is used for determining a preamble of the first message; the first node sends the first message, and a current identifier (current ID) of a physical layer collision avoidance mechanism (physical layer collision avoidance, PLCA) corresponding to the first message is used to determine a source MAC address of the first message.

Based on the above technical solution, in the ethernet communication process, the first node is used as a message sender, the synchronization signaling included in the first message sent by the first node is used to determine the preamble of the first message, and the curID of the PLCA corresponding to the first message sent by the first node is used to determine the source MAC address of the first message. That is, after the receiving side of the first message receives the first message, the preamble of the first message may be determined based on the synchronization signaling included in the first message, and the source MAC address of the first message may be determined based on the curID of the PLCA corresponding to the first message. In other words, in the method, when the first message sent by the first node does not carry the preamble of the first message and the source MAC address of the first message, the receiver of the first message may determine the preamble of the first message and the source MAC address of the first message. Therefore, in the transmission process of the Ethernet message, the method is used for saving the cost by avoiding sending the preamble of the message and the source MAC address of the message, and improving the bearing efficiency of effective data in the message so as to improve the communication efficiency.

Optionally, because the receiver of the first message can receive (or parse) the first message, the MAC address of the receiver of the first message is the destination MAC address of the first message. Therefore, in the transmission process of the ethernet message, the overhead can be saved by avoiding sending the destination MAC address of the message, and meanwhile, the bearing efficiency of the effective data in the message is further improved, so as to improve the communication efficiency.

In a possible implementation manner of the first aspect, the first packet further includes a payload (payload) and first cyclic redundancy check (cyclic redundancy check, CRC) information, where the first CRC information is generated based on the payload.

Based on the above technical solution, the first packet sent by the first node further includes payload and first CRC information, and the first CRC is generated at least based on the payload, so that the receiver of the first packet checks the payload included in the first packet based on the first CRC information, so as to improve the security of ethernet packet transmission.

In a possible implementation manner of the first aspect, the first packet further includes a virtual local area network tag (virtual local area network tag, VLAN tag) and an ethernet type (ethernet type), and the first CRC information is generated based on the VLAN tag, the ethernet type and the payload.

Based on the above technical solution, the first packet sent by the first node further includes a VLAN tag and an ethernet type, and the first CRC information is generated at least based on the VLAN tag, the ethernet type, and the payload, so that the receiver of the first packet performs verification on the VLAN tag, the ethernet type, and the payload included in the first packet based on the first CRC information, so as to further improve security of ethernet packet transmission.

Optionally, the first CRC information is generated based on only the VLAN tag, the ethernet type and the payload, and since the first packet does not need to carry a source MAC address of the first packet and a destination MAC address of the first packet, the first CRC information does not need to be generated based on the source MAC address of the first packet and the destination MAC address of the first packet, so that a receiver of the first packet can quickly implement verification.

Optionally, the first CRC information is generated based on the VLAN tag, the ethernet type, the payload, a source MAC address of the first packet, and a destination MAC address of the first packet. After determining the source MAC address and the destination MAC address of the first packet, the receiver of the first packet performs a check on the first CRC information in the first packet based on the source MAC address and the destination MAC address, so as to further improve the security of ethernet packet transmission, and meanwhile, be compatible with the existing CRC check mode in the ethernet.

In a possible implementation manner of the first aspect, the first packet further includes first indication information, where the first indication information is used to indicate a packet type of the first packet, and the packet type includes a high priority packet (output packet), a preempted packet (a complete preemptable packet), or an initial fragment of a packet (an intial fragment of a packet).

Based on the above technical solution, the existing ethernet standard supporting messages implement a priority preemption mechanism by combining the preamble and the SMD, and in order to be compatible with the preemption mechanism, if the first message sent by the first node does not include the preamble, the first message may further include first indication information for indicating a message type of the first message. Therefore, under the condition that the first message does not carry the preamble, the indication of the message type of the first message is realized through the first indication information carried by the first message, and the existing Ethernet standard is compatible.

In a possible implementation manner of the first aspect, the first packet further includes second indication information, where the second indication information is used to indicate a transmission type of the first packet, and the transmission type includes broadcast, multicast or unicast.

Based on the above technical solution, the first message sent by the first node may indicate, by displaying, that the transmission type of the first message is broadcast, multicast or unicast, that is, the indication is implemented by the second indication information carried by the first message. The receiving side of the first message confirms the transmission type of the first message based on the second indication information, and determines the destination MAC address of the first message as a broadcast address, a multicast address or a unicast address based on the transmission type, so as to realize the Ethernet message transmission mode of the destination MAC address of the message.

In a possible implementation manner of the first aspect, the transmission period of the first packet is used to indicate a transmission type of the first packet and/or a destination MAC address of the first packet, where the transmission type includes broadcast, multicast or unicast.

Based on the above technical solution, the first message sent by the first node may indicate, in an implicit manner, that the transmission type of the first message is broadcast, multicast or unicast, that is, the indication is implemented by the sending period in which the first message is located. The receiving side of the first message confirms the transmission type of the first message based on the second indication information, and determines the destination MAC address of the first message as a broadcast address, a multicast address or a unicast address based on the transmission type, so as to realize the Ethernet message transmission mode of the destination MAC address of the message.

Illustratively, during communication based on the PLCA mechanism, a master node on the PLCA bus may send announcement information at the beginning of a transmission period (transmission cycle) indicating the type of transmission of a message allowed for the current transmission period, including broadcast, multicast or unicast.

Alternatively, the nodes communicating on the PLCA bus may be a plurality of nodes (including the first node and the second node), where the plurality of nodes may respectively correspond to different addresses under different transmission types. For example, the plurality of nodes may correspond to the same broadcast address under a broadcast transmission type, the plurality of nodes may correspond to a plurality of different multicast group addresses under a multicast transmission type, and the plurality of nodes may respectively correspond to respective different unicast addresses under a unicast transmission type. For this purpose, the notification information may further include a destination MAC address of the first message, so that the receiver of the first message specifies the destination MAC address of the first message.

In a possible implementation manner of the first aspect, the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the curID of the PLCA corresponding to the first message is used for indicating the PLCA node ID; the mapping relation between the PLCA node ID and the preset mapping relation is used for determining the source MAC address of the first message; or, the PLCA node ID is a value of a part of fields of the source MAC address of the first packet, and other fields of the source MAC address of the first packet are preconfigured.

Based on the above technical solution, in the process that the first node sends the first message based on the PLCA mechanism, the curID of the PLCA corresponding to the first message may indicate the PLCA node ID corresponding to the first node. Correspondingly, after determining the PLCA node ID corresponding to the first node, the receiver of the first message determines the source MAC address of the first message based on the mapping relation between the PLCA node ID and the preset map, or determines the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID and the other fields of the source MAC address of the first message are preconfigured. Therefore, a specific implementation manner of determining the source MAC address of the first message based on the curID of the PLCA corresponding to the first message is provided, so as to realize an Ethernet message transmission manner of the source MAC address of the message without sending.

Optionally, the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the curID of the PLCA corresponding to the first message and a preset mapping relation are used for determining the source MAC address of the first message. Further alternatively, the "preset mapping relationship" may be information obtained in advance by the receiver of the first node, for example, obtained in advance by information written in advance by a user operation instruction, obtained in advance by information preconfigured in an upper node, or obtained in advance by other modes, which is not limited herein.

In a possible implementation manner of the first aspect, the length of the first packet is less than 64 bytes (byte).

Based on the above technical solution, in the process of using half duplex communication in ethernet, in order to ensure that the physical coding sub-layer (physical coding sublayer, PCS) of the transmitting end can detect the conflict before the message transmission is completed, the length of the ethernet message needs to be limited to be greater than or equal to 64 bytes. In this implementation manner, in the process that the first node sends the first message based on the PLCA mechanism, the collision detection is implemented above the PCS layer and is embodied through a media independent interface (media independent interface, MII) interface, so that the bus collision can be detected in one coding block, and the implementation manner does not need to limit the length of the ethernet message to be greater than or equal to 64 bytes. In other words, the length of the first message sent by the first node may be less than 64 bytes.

Optionally, the length of the first packet is not less than 64 bytes, i.e. the length of the first packet is greater than or equal to 64 bytes.

In a possible implementation manner of the first aspect, the first packet further includes third indication information, where the third indication information is used to indicate a packet sending state of the first packet, and the third indication information is used to separate the first packet from an adjacent packet of the first packet.

Optionally, the third indication information includes a send message success identifier (good_esd) or a send message error identifier (bad_esd).

Based on the above technical solution, in the process of sending the first message by the first node based on the PLCA mechanism, the first message may further include third indication information for indicating a message sending state of the first message, where the third indication information is located after the payload in the first message. Therefore, after the receiving side of the first message receives the first message and the adjacent messages of the first message, synchronization can be realized based on the third indication information, so that synchronization between the first message and the adjacent messages of the first message is not required through an Inter Packet Gap (IPG), the Ethernet message transmission mode without placing the IPG is realized, and meanwhile, the bearing efficiency of effective data in the message can be further improved, and the communication efficiency is improved.

The second aspect of the present application provides a communication method, which is performed by the second node, or which is performed by part of the components (e.g. a processor, a chip or a system-on-chip, etc.) in the second node, or which is implemented by a logic module or software which is capable of implementing all or part of the functionality of the second node. In the second aspect and its possible implementation manner, the communication method is described by using the second node as an example, where the second node may be a router, a switch, a virtual machine, or a device such as an on-board communication node (e.g. a camera, a sensor, a controller, etc.). In the method, a second node receives a first message, wherein the first message comprises synchronous signaling; the second node determines a preamble of the first message based on the synchronization signaling, and determines a source MAC address of the first message based on a current identifier curID of a physical layer collision free mechanism PLCA corresponding to the first message.

Based on the technical scheme, in the ethernet communication process, the second node is used as a message receiving party, the synchronous signaling contained in the first message received by the second node is used for determining the preamble of the first message, and the curID of the PLCA corresponding to the first message sent by the first node is used for determining the source MAC address of the first message. That is, after the second node receives the first message, the second node may determine the preamble of the first message based on the synchronization signaling included in the first message and determine the source MAC address of the first message based on the curID of the PLCA corresponding to the first message. In other words, in the method, when the first message sent by the first node does not carry the preamble of the first message and the source MAC address of the first message, the receiver of the first message may determine the preamble of the first message and the source MAC address of the first message. Therefore, in the transmission process of the Ethernet message, the method is used for saving the cost by avoiding sending the preamble of the message and the source MAC address of the message, and improving the bearing efficiency of effective data in the message so as to improve the communication efficiency.

In a possible implementation manner of the second aspect, the first packet further includes a payload and first cyclic redundancy check CRC information, and the first CRC information is generated based on the payload.

Based on the above technical solution, the first packet received by the second node further includes payload and first CRC information, and the first CRC is generated at least based on the payload, so that the second node checks the payload included in the first packet based on the first CRC information, so as to improve the security of ethernet packet transmission.

In a possible implementation manner of the second aspect, the first packet further includes a VLAN tag and an ethernet type ethernet, and the first CRC information is generated based on the VLAN tag, the ethernet type and the payload; the method further comprises the steps of: when the second node determines that the first CRC information is successfully checked, the second node updates the first CRC information into second CRC information, wherein the second CRC information is generated based on a source MAC address of the first message, a destination MAC address of the first message, the VLAN tag, the ETHERTYPE and the payload.

Based on the above technical solution, the first packet received by the second node further includes a VLAN tag and an ethernet type, and the first CRC information is generated at least based on the VLAN tag, the ethernet type, and the payload, so that the second node checks the VLAN tag, the ethernet type, and the payload included in the first packet based on the first CRC information, so as to further improve security of ethernet packet transmission. In addition, the second node may update the first CRC information to second CRC information when it is determined that the first CRC information check is successful, where the second CRC information is generated based on a source MAC address of the first packet, a destination MAC address of the first packet, the VLAN tag, the ethernet type, and the payload, so as to be compatible with a CRC check manner in an existing ethernet network.

Optionally, the first CRC information is generated based on only the VLAN tag, the ethernet type, and the payload, and since the first packet does not need to carry a source MAC address of the first packet and a destination MAC address of the first packet, the first CRC information does not need to be generated based on the source MAC address of the first packet and the destination MAC address of the first packet, so that the second node can quickly implement verification.

Optionally, the first CRC information is generated based on the VLAN tag, the ethernet type, the payload, a source MAC address of the first packet, and a destination MAC address of the first packet. After determining the source MAC address and the destination MAC address of the first packet, the second node performs a check on the first CRC information in the first packet based on the source MAC address and the destination MAC address, so as to further improve the security of ethernet packet transmission, and meanwhile, is compatible with the existing CRC check mode in the ethernet.

In a possible implementation manner of the second aspect, the destination MAC address of the first packet is a broadcast address, a multicast address of a multicast group in which the second node is located, or a unicast address of the second node.

Based on the above technical solution, because the second node can receive (or parse) the first message, the MAC address of the second node is the destination MAC address of the first message. Therefore, in the transmission process of the ethernet message, the overhead can be saved by avoiding sending the destination MAC address of the message, and meanwhile, the bearing efficiency of the effective data in the message is further improved, so as to improve the communication efficiency.

In a possible implementation manner of the second aspect, the determining, by the second node, the preamble of the first packet based on the synchronization signaling, and determining, by the second node, the source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet includes: when the second node determines that the first message is legal based on the curID of the PLCA corresponding to the first message, the second node determines the preamble of the first message based on the synchronous signaling, and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message.

Optionally, the determining, by the second node, that the first message is a legal message based on the curID of the PLCA corresponding to the first message may also be expressed as: the second node determines that the sender of the first message is a legal node based on the curID of the PLCA corresponding to the first message.

Based on the above technical solution, in the process that the second node determines the preamble of the first message based on the synchronization signaling and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message, the second node may first determine that the first message is a legal message based on the curID of the PLCA corresponding to the first message, and then parse the first message, that is, the second node determines the preamble of the first message based on the synchronization signaling and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message. Therefore, in the process of receiving the first message based on the PLCA mechanism, the second node receives (or analyzes) the interested message by filtering the curID of the PLCA corresponding to the received message, and does not need to receive (or analyze) all the messages, so that unnecessary expenditure is avoided.

In a possible implementation manner of the second aspect, the first packet further includes first indication information, where the first indication information is used to indicate a packet type of the first packet, where the packet type includes a high priority packet, a preempted packet, or an initial fragment of a packet.

In a possible implementation manner of the second aspect, the first packet further includes second indication information, where the second indication information is used to indicate a transmission type of the first packet, and the transmission type includes broadcast, multicast or unicast.

In a possible implementation manner of the second aspect, the transmission period of the first packet is used to indicate a transmission type of the first packet and/or a destination MAC address of the first packet, where the transmission type includes broadcast, multicast or unicast.

Alternatively, the nodes communicating on the PLCA bus may be a plurality of nodes (including the first node and the second node), where the plurality of nodes may respectively correspond to different addresses under different transmission types. For example, the plurality of nodes may correspond to the same broadcast address under a broadcast transmission type, the plurality of nodes may correspond to a plurality of different multicast group addresses under a multicast transmission type, and the plurality of nodes may respectively correspond to respective different unicast addresses under a unicast transmission type. For this purpose, the notification information may also include the destination MAC address of the first message, so that the receiver of the first message specifies the destination MAC address of the first message

In a possible implementation manner of the second aspect, the determining, based on the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the method comprises the steps that a source MAC address of a first message is determined based on a mapping relation between a PLCA node ID indicated by a curID of the PLCA corresponding to the first message and a preset; or determining the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID indicated by the curID of the PLCA corresponding to the first message, wherein other fields of the source MAC address of the first message are preconfigured.

Based on the above technical solution, in the process that the second node receives the first message based on the PLCA mechanism, the curID of the PLCA corresponding to the first message may indicate the PLCA node ID corresponding to the first node. Correspondingly, after determining the PLCA node ID corresponding to the first node, the second node determines the source MAC address of the first message based on the mapping relation between the PLCA node ID and the preset map, or determines the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID and the other fields of the source MAC address of the first message are preconfigured. Therefore, a specific implementation manner of determining the source MAC address of the first message based on the curID of the PLCA corresponding to the first message is provided, so as to realize an Ethernet message transmission manner of the source MAC address of the message without sending.

Optionally, the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the curID of the PLCA corresponding to the first message and a preset mapping relation are used for determining the source MAC address of the first message. Further alternatively, the "preset mapping relationship" may be information obtained in advance for the second node, for example, obtained in advance by information written in advance by a user operation instruction, obtained in advance by information preconfigured in advance by an upper node, or obtained in advance by other modes, which is not limited herein.

In a possible implementation manner of the second aspect, the length of the first packet is less than 64 bytes.

Optionally, the length of the first packet is greater than or equal to 64 bytes.

In a possible implementation manner of the second aspect, the first packet further includes third indication information, where the third indication information is used to indicate a packet sending state of the first packet, and the third indication information is used to separate the first packet from an adjacent packet of the first packet.

A third aspect of the present application provides a communication device capable of implementing the method of the first aspect or any one of the possible implementation manners of the first aspect. The apparatus comprises corresponding units or modules for performing the above-described methods. The units or modules included in the apparatus may be implemented in a software and/or hardware manner. For example, the device may be a communication device, or the device may be a component in a communication device (e.g., a processor, a chip, or a system-on-a-chip, etc.), or the device may also be a logic module or software that is capable of implementing all or part of the functionality of the communication device.

The communication device comprises a processing unit and a receiving and transmitting unit;

the processing unit is used for determining a first message, wherein the first message comprises synchronous signaling, and the synchronous signaling is used for determining a preamble of the first message;

the receiving and transmitting unit is configured to send the first packet, where a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first packet is used to determine a source MAC address of the first packet.

In a possible implementation manner of the third aspect, the first packet further includes a payload and first cyclic redundancy check CRC information, and the first CRC information is generated based on the payload.

In a possible implementation manner of the third aspect, the first packet further includes a VLAN tag and an ethernet type ethernet, and the first CRC information is generated based on the VLAN tag, the ethernet type and the payload.

In a possible implementation manner of the third aspect, the first packet further includes first indication information, where the first indication information is used to indicate a packet type of the first packet, where the packet type includes a high priority packet, a preempted packet, or an initial fragment of a packet.

In a possible implementation manner of the third aspect, the first packet further includes second indication information, where the second indication information is used to indicate a transmission type of the first packet, and the transmission type includes broadcast, multicast or unicast.

In a possible implementation manner of the third aspect, the transmission period of the first packet is used to indicate a transmission type of the first packet and/or a destination MAC address of the first packet, where the transmission type includes broadcast, multicast or unicast.

In a possible implementation manner of the third aspect, the determining, by using the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the curID of the PLCA corresponding to the first message is used for indicating the PLCA node ID; the mapping relation between the PLCA node ID and the preset mapping relation is used for determining the source MAC address of the first message; or, the PLCA node ID is a value of a part of fields of the source MAC address of the first packet, and other fields of the source MAC address of the first packet are preconfigured.

In a possible implementation manner of the third aspect, the length of the first packet is less than 64 bytes.

In a possible implementation manner of the third aspect, the first packet further includes third indication information, where the third indication information is used to indicate a packet sending state of the first packet, and the third indication information is used to separate the first packet from an adjacent packet of the first packet.

In the third aspect of the embodiment of the present application, the constituent modules of the communication device may also be used to execute the steps executed in each possible implementation manner of the first aspect, and reference may be specifically made to the first aspect, which is not repeated herein.

A fourth aspect of the present application provides a communications device capable of implementing the method of the second aspect or any one of the possible implementations of the second aspect. The apparatus comprises corresponding units or modules for performing the above-described methods. The units or modules included in the apparatus may be implemented in a software and/or hardware manner. For example, the device may be a communication device, or the device may be a component in a communication device (e.g., a processor, a chip, or a system-on-a-chip, etc.), or the device may also be a logic module or software that is capable of implementing all or part of the functionality of the communication device.

The communication device comprises a transceiver unit and a processing unit.

The receiving and transmitting unit is used for receiving a first message, and the first message comprises synchronous signaling;

the processing unit is configured to determine a preamble of the first message based on the synchronization signaling, and determine a source MAC address of the first message based on a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first message.

In a possible implementation manner of the fourth aspect, the first packet further includes a payload and first cyclic redundancy check CRC information, and the first CRC information is generated based on the payload.

In a possible implementation manner of the fourth aspect, the first packet further includes a VLAN tag and an ethernet type ethernet, and the first CRC information is generated based on the VLAN tag, the ethernet type and the payload; the processing unit is further configured to update the first CRC information to second CRC information when it is determined that the first CRC information check is successful, where the second CRC information is generated based on a source MAC address of the first packet, a destination MAC address of the first packet, the VLAN tag, the ethernet type, and the payload.

In a possible implementation manner of the fourth aspect, the destination MAC address of the first packet is a broadcast address, a multicast address of a multicast group where the second node is located, or a unicast address of the second node.

In a possible implementation manner of the fourth aspect, when determining that the first packet is a legal packet based on the curID of the PLCA corresponding to the first packet, the processing unit determines a preamble of the first packet based on the synchronization signaling, and determines a source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet.

In a possible implementation manner of the fourth aspect, the first packet further includes first indication information, where the first indication information is used to indicate a packet type of the first packet, where the packet type includes a high priority packet, a preempted packet, or an initial fragment of a packet.

In a possible implementation manner of the fourth aspect, the first packet further includes second indication information, where the second indication information is used to indicate a transmission type of the first packet, and the transmission type includes broadcast, multicast or unicast.

In a possible implementation manner of the fourth aspect, the transmission period of the first packet is used to indicate a transmission type of the first packet and/or a destination MAC address of the first packet, where the transmission type includes broadcast, multicast or unicast.

In a possible implementation manner of the fourth aspect, the processing unit is specifically configured to: the method comprises the steps that a source MAC address of a first message is determined based on a mapping relation between a PLCA node ID indicated by a curID of the PLCA corresponding to the first message and a preset; or determining the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID indicated by the curID of the PLCA corresponding to the first message, wherein other fields of the source MAC address of the first message are preconfigured.

In a possible implementation manner of the fourth aspect, the length of the first packet is less than 64 bytes.

In a possible implementation manner of the fourth aspect, the first packet further includes third indication information, where the third indication information is used to indicate a packet sending state of the first packet, and the third indication information is used to separate the first packet from an adjacent packet of the first packet.

In the fourth aspect of the embodiment of the present application, the constituent modules of the communication device may also be used to perform the steps performed in each possible implementation manner of the second aspect, and in particular, reference may be made to the second aspect, which is not repeated here.

A fifth aspect of embodiments of the present application provides a communication device comprising at least one processor coupled to a memory;

the memory is used for storing programs or instructions;

the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method according to the first aspect or any one of the possible implementation manners of the first aspect.

A sixth aspect of the embodiments of the present application provides a communication device comprising at least one processor coupled to a memory;

the memory is used for storing programs or instructions;

the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method according to the second aspect or any one of the possible implementation manners of the second aspect.

A seventh aspect of the embodiments of the present application provides a computer readable storage medium for storing one or more computer executable instructions which, when executed by a processor, perform a method as described above in the first aspect or any one of the possible implementations of the first aspect.

An eighth aspect of the embodiments of the present application provides a computer-readable storage medium storing one or more computer-executable instructions which, when executed by a processor, perform a method as described in the second aspect or any one of the possible implementations of the second aspect.

A ninth aspect of the embodiments of the present application provides a computer program product (or computer program) which, when executed by a processor, performs the method of any one of the above-mentioned first aspect or any one of the possible implementations of the first aspect.

A tenth aspect of the embodiments of the present application provides a computer program product (or computer program) which, when executed by a processor, performs the method of the second aspect or any one of the possible implementations of the second aspect.

An eleventh aspect of the embodiments of the present application provides a chip system comprising at least one processor for supporting a first network device to implement the functionality referred to in the first aspect or any one of the possible implementations of the first aspect. In one possible design, the system-on-chip may further include a memory to hold the necessary program instructions and data for the communication device. The chip system can be composed of chips, and can also comprise chips and other discrete devices. Optionally, the system on a chip further comprises interface circuitry providing program instructions and/or data to the at least one processor.

A twelfth aspect of the embodiments of the present application provides a chip system comprising at least one processor for supporting a first network device to implement the functionality involved in the second aspect or any one of the possible implementations of the second aspect. In one possible design, the system-on-chip may further include a memory to hold the necessary program instructions and data for the communication device. The chip system can be composed of chips, and can also comprise chips and other discrete devices. Optionally, the system on a chip further comprises interface circuitry providing program instructions and/or data to the at least one processor.

A thirteenth aspect of the embodiments of the present application provides a communication system comprising the communication device of the third aspect and any of the possible implementations thereof and the communication device of the fourth aspect and any of the possible implementations thereof, and/or the communication system comprises the communication device of the fifth aspect and any of the possible implementations thereof and the communication device of the sixth aspect and any of the possible implementations thereof.

The technical effects of any one of the design manners of the third aspect to the thirteenth aspect may be referred to the technical effects of the different implementation manners of the first aspect or the second aspect, and are not described herein.

Drawings

FIG. 1 is a diagram of a message format;

FIG. 2 is a schematic illustration of an in-vehicle network;

FIG. 3a is a schematic diagram of a PLCA mechanism implementation;

FIG. 3b is another schematic diagram of a PLCA mechanism implementation;

FIG. 4 is a schematic diagram of an implementation of an arbitration mechanism;

FIG. 5 is another diagram of a message format;

FIG. 6 is a schematic diagram of a communication method provided by the present application;

FIG. 7 is another schematic diagram of a communication method provided by the present application;

FIG. 8 is another schematic diagram of a communication method provided by the present application;

FIG. 9 is another schematic diagram of a communication method provided by the present application;

FIG. 10 is a diagram illustrating a message format according to the present application;

FIG. 11 is a diagram illustrating another message format according to the present application;

FIG. 12 is another diagram illustrating a message format according to the present application;

FIG. 13 is another schematic diagram of a communication method provided by the present application;

FIG. 14 is another schematic diagram of a communication method provided by the present application;

FIG. 15 is another diagram illustrating a message format according to the present application;

FIG. 16 is another diagram illustrating a message format according to the present application;

FIG. 17 is another schematic diagram of a communication method provided by the present application;

FIG. 18 is a schematic diagram of a communication device according to the present application;

fig. 19 is another schematic diagram of a communication device provided by the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be understood that the terms "system" and "network" in embodiments of the application may be used interchangeably. "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: cases where A alone, both A and B together, and B alone, where A and B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one of A, B, and C" includes A, B, C, AB, AC, BC, or ABC. And, unless otherwise specified, references to "first," "second," etc. ordinal words of embodiments of the present application are used for distinguishing between multiple objects and not for defining a sequence, timing, priority, or importance of the multiple objects.

The application is mainly applied to the field of Ethernet (Ethernet) communication, wherein the Ethernet is a computer local area network technology commonly used at present. The IEEE 802.1 and IEEE 802.3 standards set technical standards for ethernet. The IEEE established the 802.3 standard in 1980, which represents the advent of ethernet. Since ethernet has been generated, a packet forwarding method, i.e., a forwarding method of destination forwarding (destination forwarding), has been used. This approach naturally supports statistical multiplexing of link bandwidths. In addition, the Ethernet equipment supports the characteristics of plug and play and the like because of low price, and has high deployment rate. Operators, equipment manufacturers, instrument-manufacturers, device manufacturers, chip manufacturers, etc. support the development of ethernet technology, which has been developed for decades, with almost the largest ecological circle and mature industry chains.

The ethernet message format is illustrated in fig. 1, for example.

As shown in fig. 1, in Layer 1 ethernet messages and message intervals (Layer 1 Ethernet packer&IPG), a Layer 1 ethernet message portion occupying 72 to 1530 bytes (octets) is included, and an IPG portion occupying 12 bytes.

Further, the layer 1 ethernet message portion includes the following fields:

A preamble (preamble), a frame start interval (start frame delimiter), a destination MAC (MAC destination) address, a source MAC (MAC source) address, an 802.1Q tag (802.1Q tag, or VLAN tag), an ethertype or length (ethertype or length), a payload (payload), and a frame check sequence (frame check sequence).

As shown in fig. 1, the following fields are included in the layer 2 ethernet frame:

destination MAC (MAC destination) address, source MAC (MAC source) address, 802.1Q tag (802.1Q tag, or VLAN tag), ethertype or length (ethertype or length), payload (payload), frame check sequence (frame check sequence).

Optionally, the frame check sequence field shown in fig. 1 is generated based on the destination MAC address, the source MAC address, the VLAN tag, the ethertype or length, and the payload portion.

Alternatively, in fig. 1, the ethernet frame start portion is started by one frame with a preamble (preamble) of 7 bytes and a frame start interval (start frame delimiter) of 1 byte; an ethernet header follows to describe the destination address and the source address in terms of MAC addresses. The middle of a frame is the packet (e.g., IP protocol) that the frame carries that contains the other protocol headers. The header contains the MAC addresses of the source and destination addresses, an ethertype field and optionally an IEEE 802.1Q VLAN tag to account for VLAN membership and transmission priority. The frame check sequence (frame check sequence) is a 32-bit cyclic redundancy check code to verify whether the frame data is corrupted. After a Frame is sent out, the sender needs to wait for a Frame interval (IPG: inter Frame Gap) of 12 more octets before sending the Frame next time.

The application of ethernet technology in an in-vehicle network is described below.

The vehicle network (in-vehicle network) is fully mechanized from the beginning, and is subjected to gradual evolution towards the vehicle ring network through a bus network, a direct connection network, a regional network domain architecture and the like. As shown in fig. 2, the vehicle ring network is an in-vehicle backbone network, and is connected to a plurality of gateway communication devices. Currently, the on-board ring backbone network (e.g. the cabin domain controller (cockpit domain controller, CDC), the mobile data center (mobile data center, MDC) in fig. 2, the network connected between devices such as the whole vehicle controller (vehicle domain controller, VDC), gateway device (GW) and the like) is mainly an ethernet network, for example, 5 gigabit seconds (Gbps), 10Gbps and the like, and may evolve in future like a larger bandwidth. The access network of the ring network is mainly a network (connection is not shown in the figure) for connecting devices such as cameras, sensors, radars and the like shown in fig. 2 with devices in the backbone network. With the continuous increase of pixel and frame rates, the bandwidth of the vehicle ring network access link is gradually increased, from the first K level to the M level rate and the G level rate. Current vehicle access technologies are relatively many, such as the oldest serial technologies based on low voltage differential signaling (Low Voltage Differential Signaling, LVDS) and serial-parallel converters (SerDes), but none of these technologies are ethernet technologies, which are not compatible with current ring network ethernet technologies.

To make up for the technical blank of the ethernet on the low-speed access side, the IEEE 802 working group defines a 10Mbps bandwidth network through the 802.3cg protocol, while supporting end-to-end transmission (10 Base-T1S,10 Base-T1L) and bus type shared network (10 Base-T1S). Wherein 10Base-T1S simultaneously supports a collision free bus access mechanism (i.e., PLCA) to improve bus bandwidth utilization.

As shown in fig. 3a, in the communication process based on the PLCA mechanism, the bus communication mode is half duplex, and multi-point communication (multi-drop), i.e. bus sharing medium, is supported. As shown in fig. 3a, a master (master) node and a slave (slave) node are defined inside the PLCA bus. The Master node controls the data transmission of the individual nodes of the bus by defining different transmission periods (transmission cycle). Each transmission period is started by Master transmit Beacon (Beacon) signaling. Each slave node determines whether data can be currently transmitted by calculating the ID of the current transmitting node. Each slave node has an opportunity to transmit data during the transmit period. Each slave node is assigned a bus unique ID (i.e., PLCA node ID) and confirms whether the current transmission window belongs to the node through local calculation.

Optionally, before the slave node speaks, the channel occupancy is identified by sending a guaranteed (commit) signaling. The same slave node also transmits commit signaling for synchronization between the multiple messages. Taking the node "1" in fig. 3a as an example, the node "1" sends the commit signaling to identify the channel occupation at the speaking position corresponding to the transmission period, and the Data sent by the node "1" is located at the position of the "physical side Data (Data PHY) 1". Similarly, in fig. 3a, node "3" sends a commit signaling to identify channel occupancy at the floor location corresponding to the transmission period, and the Data sent by node "3" is located at the location of "Data PHY 3".

Optionally, before the slave node speaks, it identifies that the channel is unoccupied by sending a yield (yield) signaling, or that the node does not send data at the corresponding location. Taking node "2" in fig. 3a as an example, node "2" sends a yield signaling to identify that the channel is unoccupied at the floor position corresponding to the transmission period, and node "2" does not send other data in the transmission period, followed by signaling and data of the next node (i.e., node "3").

In addition, the PLCA mechanism is a mechanism that advertises the current bus state of each node through physical layer signaling. And the synchronization of each node of the bus is realized by adding signaling in an Ethernet RS layer. As shown in fig. 3b, the PLCA layer is located below the logical link layer (logical link layer) and the medium access control (media access control, MAC) layers, and the PLCA layer is located above the physical coding sublayer (physical coding sublayer, PCS) and the physical medium adaptation (physical medium attachment, PMA) layers. Newly added signaling BEACON and COMMIT are implemented below the RS layer, and the MAC layer is unaware (does not modify the upper MII, RMII interfaces).

The controller area network (controller area network, CAN) in the current in-vehicle network will be described below.

As a dominant technology in the current vehicle-mounted communication system, CAN is a technology which has been about 40 years old. Even in modern new energy vehicles, CAN is believed to be the primary technology for in-vehicle communication. The CAN communication mode is bus type multi-host communication. The communication nodes are equal in position and are not differentiated from master nodes and slave nodes. And the bus type broadcasting mechanism is used for realizing single-shot and multi-receipt of data on a bus, and a CAN identification filtering (CAN ID filter) mode is realized on each node, and whether a currently received message belongs to the user or not is judged by filtering the ID of the received CAN data.

The CAN network comprises a plurality of versions, and the transmission rates of the different versions are different and are downward compatible. Wherein CAN 1.0 and CAN 2.0 are CAN early versions supporting 11-bit CAN ID and 29-bit CAN ID, respectively. At the communication rate, 50 kilobits per second (Kbits), 125 Kbits/s, 500 Kbits/s, up to 1 megabit per second (Mbit/s) are supported, respectively, according to the characteristics of the physical layer. The flexible data rate CAN (CAN flexible data rate, CAN FD) improves bus communication rate (up to 5 Mbps) over the original CAN version and improves maximum frame length to 64 bytes. However, as the demand for bandwidth for in-vehicle communications increases, the CAN automation (CAN in automation, ciA) organization has been working on the new generation of CAN standards, CAN XL. This standard is expected to boost the CAN bus bandwidth to 10Mbit/s and to increase the packet level to 2048 bytes. And simultaneously, CAN data transmission is supported, and an Ethernet message CAN be carried.

Because the CAN bus adopts a Multi-Master Multi-host communication mechanism, in order to avoid bus collision during data transmission, the CAN network realizes a bit and arbitration mechanism, and the principle of the CAN network is shown in figure 4. The CAN bus node receives data simultaneously when transmitting the data, and confirms whether the current data transmission generates conflict or not by comparing the data transmitted by the CAN bus node with the received data. Each CAN node will first monitor whether it is idle on the bus before sending data. If the bus is not idle, the node will wait for the current data transmission to be completed and then try to transmit again. If the current bus is idle, the transmitting node will first transmit the start of frame (start of the frame, SOF), pull the bus while informing other nodes that there is currently data to transmit. To avoid multiple nodes transmitting data simultaneously, the current transmitting node may transmit data ID. first at the beginning of data transmission, with each data having a different ID and a higher priority as the ID is smaller. When different data simultaneously send IDs, the data with high priority can pull down the bus earlier, so that arbitration of other messages with low priority fails. The node that failed arbitration will brake out of the current data transmission, so that higher priority data gets priority to transmit if multiple nodes transmit data at the same time.

Illustratively, in FIG. 4, the communication nodes on the bus (bus) include node A (node A), node B (node B), node C (node C), and node D (node D).

As shown in fig. 4, in the arbitration phase (arbitration phase), when node a, node B and node C are detected on the bus and each send a SOF to notify other nodes that there is currently data to send, then node a, node B and node C need to undergo further arbitration thereafter; and node D does not send SOF default node D no data to send, node D exits the current arbitration phase and enters a receiving mode (reception mode), corresponding to arrow "1".

Further, as shown in fig. 4, the arbitration phase is exited when node a, node B and node C each transmit their own data identity (message identifier, otherwise referred to as a data ID) until some bit of their own data ID is found to be lower than the corresponding bit of the data ID of the other nodes. For example, after the node B sends a high level signal at bit "5", if it finds that there are other low level signals, the node B exits the current arbitration phase to enter a receiving mode, corresponding to arrow "2"; for another example, after the node a sends a high level signal at bit "3", if it finds that there are other low level signals, the node a exits the current arbitration phase to enter the receiving mode, corresponding to arrow "3". As can be seen from the example shown in fig. 4, for the node C, after the bit transmission of the data ID corresponding to the bit "2", it is found that no other node participates in arbitration, it is determined that the node C obtains the priority transmission right, and the data transmission process is performed after the bits of the data IDs corresponding to the bits "1" and "0" are transmitted.

Optionally, the data transmission process includes the following fields:

remote transmission applications (remote transmission request, RTR), control field (control field), data field (data field), CRC field (CRC field), response field (ACK field), frame termination identity (EOF), frame gap (inter frame space) IFS.

In general, an on-board bus network primarily carries vehicle control signals and sensor signals. The method has the characteristics of small data volume and high real-time performance. The small data volume is mainly reflected in the short length of a single message. Control signaling in the current vehicle-mounted system is often communicated through a CAN bus, and the data length of the CAN bus is generally about 8 Byte. High real-time performance is manifested in that the transmitted data often requires that the transmission be completed before a specified Deadline (Deadline). For example, the maximum delay of the steering control signal is often less than 10 milliseconds (ms). Ethernet often has bandwidth utilization problems when transmitting small-throughput, high-real-time data. The IEEE802.3 protocol specifies that the ethernet minimum message length be 64 bytes. Wherein the payload portion has a minimum length of 46 bytes. If the data is less than 46 bytes, the MAC layer automatically fills in 0 for padding, an operation called padding. It is apparent that the interleaved ethernet packet uses a 64 byte length packet to transfer 8 bytes of application data. In the physical layer transmission of the message, a preamble and a frame interval need to be additionally added. The bandwidth utilization is only 8/(72+12) =9%. In order to improve bandwidth utilization, the concept of a protocol data unit Container (Container protocol data unit, container PDU) is currently defined, and a plurality of small messages are encapsulated in a fixed format and sent together in one ethernet message. Although this mechanism solves the problem of bandwidth utilization, it is necessary to wait for the application layer to combine multiple protocol data unit containers (protocol data unit, PDU) into one large message, and the real-time performance of data transmission cannot be guaranteed.

However, as a peer-to-peer technology, CAN networks have no limitation of minimum message length when transmitting data, and the data includes only an ID of one information to identify the type of information. The advantages over ethernet are significant in terms of bandwidth utilization.

Illustratively, as shown in fig. 5, CAN supports standard frame and extended frame message formats.

The standard frame includes the following parts:

bus idle (bus idle);

frame initiation: SOF;

arbitration field: identification (ID), RTR;

and (3) a control field: extension identity (identification extended, IDE), r, data length identity (data length count, DLC);

data field: data field;

CRC field: CRC, separator (DEL);

ACK field: acknowledgement (ACK), DEL;

end of frame: EOF;

frame transmission Interval (ITM);

bus idle (bus idle);

the extended frame includes the following parts:

bus idle (bus idle);

frame initiation: SOF;

arbitration field: ID, substituted remote application (substitute remote request, SRR), IDE, extended message identification (extended ID), RTR;

and (3) a control field: reserved usage (Reserved for Future use, r 1) field, resynchronisation bit (resynchronization bit, r 0), DLC;

Data field: data field;

CRC field: CRC, DEL;

ACK field: ACK, DEL;

end of frame: EOF;

ITM；

bus idle (bus idle);

it can be seen that under the standard frame format, the ID is 11 bits, and the bearing efficiency of the effective data is 79 bits/(79+32) bits=71%. In the extended frame format, the ID length is 29bit ID, and the bearing efficiency of the effective data is 79 bit/(79+52) bit=60%.

In terms of bandwidth, the physical bandwidth of the PLCA network based on the Ethernet technology is 10Mbps, but the bearing efficiency is 9%, so that the transmission bandwidth of effective data is 900Kbps, while the bandwidth of CAN/CAN FD is 1Mbps to 5Mbps, and the transmission bandwidth of effective data is 700Kbps to 3.5Mbps at 70% bearing efficiency.

It should be understood that the foregoing description is given by taking the example that "valid data" includes data in a data field and data in a CRC field, and that "valid data" may also include only data in a data field, which is only exemplary.

From the above, it can be seen that the current effective data carrying efficiency is low in the ethernet message transmission process, which affects the communication efficiency. Therefore, how to improve the bearing efficiency of the effective data to improve the communication efficiency in the transmission process of the ethernet message is a technical problem to be solved.

In order to solve the above problems, the present application provides a communication method and a communication device, which are used for improving the bearing efficiency of effective data in a message to improve the communication efficiency in the transmission process of an ethernet message. The communication method and the communication device provided by the application will be described in detail below with reference to the accompanying drawings.

Referring to fig. 6, a schematic diagram of a communication method according to the present application is provided, and the method includes the following steps.

S101, a first node determines a first message.

In this embodiment, the first node determines in step S101 a first packet including synchronization signaling for determining a preamble of the first packet.

In one possible implementation, the first message is less than 64 bytes (bytes) in length.

Specifically, in the process of using half duplex communication in ethernet, in order to ensure that the physical coding sub-layer (physical coding sublayer, PCS) of the transmitting end can detect the collision before the message transmission is completed, the length of the ethernet message needs to be limited to be greater than or equal to 64 bytes. In the present implementation, because the first node implements above the PCS layer and implements through the media independent interface (media independent interface, MII) interface in the process of determining the first packet in step S101 based on the PLCA mechanism, the bus collision can be detected in one coding block, so that the present implementation does not need to limit the length of the ethernet packet to be greater than or equal to 64 bytes. In other words, the length of the first message sent by the first node may be less than 64 bytes.

By way of example, ethernet technology is initially a 10Mbps bus access, half duplex access and carrier sense collision avoidance via CSMA/CD technology, and specifies a minimum frame length of 64 bytes for the message. The definition is calculated according to the standard maximum length of 2.5km of the Ethernet, and the 802.3 standard takes the double round trip delay of the Ethernet with the length reaching the maximum value as follows:

51.2μs＝(2500*4)/((1.9～2.4)*10 ⁸ )s；

wherein the propagation rate of the electromagnetic signal on the copper medium is 1.9x10 ⁸ Up to 2.4X10 ⁸ m/s. To ensure that the sender detects a collision before the message transmission is completed. In order for the "collision detection" mechanism to succeed, the ethernet frame must last at least 2t in time (2 t in time after which the next data frame has not yet been transmitted). the size of t is defined by the network protocol standard, and when t is determined, the shortest data frame is also determined, and conversely, a collision domain maximum range is also determined, 2t is defined as 51.2us and the shortest frame length is 64byte in the ethernet. It should be appreciated that in the case of full duplex communication for current ethernet networks, there is no need to support a minimum message length since the ethernet networks do not need collision detection.

In the process of determining the first message based on the PLCA mechanism in step S101, the first node also communicates through a half-duplex bus, but the bus length is only 25 meters (m). In the case of a 10Mbps bus rate, a single bit time= 1*e ^-7 s. The time for transmitting light in the copper wire for 25m is 25 x 2/3*e ⁸ ＝1.6*e ^-7 s. PLCA uses 4B/5B coding, and collision detection is implemented above PCS layer and embodied by MII interface, so that bus collision can be detected in one coding block. Thus, there is no need to support the provision of a minimum message length of 64 bytes within a 10BaseT1S bus type network.

Optionally, the length of the first packet may be greater than or equal to 64 bytes.

S102, the first node sends a first message.

In this embodiment, the first node sends a first message in step S102, and correspondingly, the second node receives the first message in step S102.

In one possible implementation, the first message further includes a payload (payload) and first cyclic redundancy check (cyclic redundancy check, CRC) information, the first CRC information being generated based on the payload. Specifically, the first message sent by the first node in step S102 further includes payload and first CRC information, and the first CRC is generated at least based on the payload, so that the receiver of the first message checks the payload included in the first message based on the first CRC information, so as to improve the security of ethernet message transmission.

Optionally, the first packet further includes a VLAN tag and an ethernet type, and the first CRC information is generated based on the VLAN tag, the ethernet type, and the payload. Specifically, the first message sent by the first node in step S102 further includes a VLAN tag and an ethernet type, and the first CRC information is generated based on at least the VLAN tag, the ethernet type, and the payload, so that the receiver of the first message checks the VLAN tag, the ethernet type, and the payload included in the first message based on the first CRC information, so as to further improve the security of ethernet message transmission.

It should be understood that the "ethernet" included in the first packet may also be an "ethernet type or length (ETHERTYPE or length)" field shown in fig. 1, and its implementation may be described with reference to fig. 1.

In one possible implementation, the first message further includes first indication information, where the first indication information is used to indicate a message type of the first message, where the message type includes a high priority message (express packet), a preempted message (a complete preemptable packet), or an initial fragment of a message (an intial fragment of a packet). Specifically, the existing ethernet standard supporting messages implement a priority preemption mechanism by combining the preamble and the SMD, and in order to be compatible with the preemption mechanism, if the first message sent in step S102 does not include the preamble, the first message may further include first indication information for indicating a message type of the first message. Therefore, under the condition that the first message does not carry the preamble, the indication of the message type of the first message is realized through the first indication information carried by the first message, and the existing Ethernet standard is compatible.

In one possible implementation, the first packet further includes second indication information, where the second indication information is used to indicate a transmission type of the first packet, and the transmission type includes broadcast, multicast, or unicast. Specifically, the first message sent by the first node in step S102 may indicate, by displaying, that the transmission type of the first message is broadcast, multicast or unicast, that is, the indication is implemented by the second indication information carried by the first message. The receiving side of the first message confirms the transmission type of the first message based on the second indication information, and determines the destination MAC address of the first message as a broadcast address, a multicast address or a unicast address based on the transmission type, so as to realize the Ethernet message transmission mode of the destination MAC address of the message.

In another possible implementation manner, the transmission period of the first message is used to indicate a transmission type of the first message and/or a destination MAC address of the first message, where the transmission type includes broadcast, multicast or unicast. Specifically, the first message sent by the first node in step S102 may indicate that the transmission type of the first message is broadcast, multicast or unicast in an implicit manner, that is, the indication is implemented through a sending period in which the first message is located. The receiving side of the first message confirms the transmission type of the first message based on the second indication information, and determines the destination MAC address of the first message as a broadcast address, a multicast address or a unicast address based on the transmission type, so as to realize the Ethernet message transmission mode of the destination MAC address of the message.

In one possible implementation manner, the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the curID of the PLCA corresponding to the first message is used for indicating the PLCA node ID; the mapping relation between the PLCA node ID and the preset mapping relation is used for determining the source MAC address of the first message; or, the PLCA node ID is a value of a part of fields of the source MAC address of the first packet, and other fields of the source MAC address of the first packet are preconfigured. Specifically, in the process of the first message sent by the first node in step S102, the curID of the PLCA corresponding to the first message may indicate the PLCA node ID corresponding to the first node. Correspondingly, after determining the PLCA node ID corresponding to the first node, the receiver of the first message determines the source MAC address of the first message based on the mapping relation between the PLCA node ID and the preset map, or determines the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID and the other fields of the source MAC address of the first message are preconfigured. Therefore, a specific implementation manner of determining the source MAC address of the first message based on the curID of the PLCA corresponding to the first message is provided, so as to realize an Ethernet message transmission manner of the source MAC address of the message without sending.

In one possible implementation manner, the first message further includes third indication information, where the third indication information is used to indicate a message sending state of the first message, and the third indication information is used to separate the first message from an adjacent message of the first message.

Specifically, in the process of the first packet sent in step S102, the first packet may further include third indication information for indicating a packet sending state of the first packet, where the third indication information is located after the payload in the first packet. Therefore, after the receiving side of the first message receives the first message and the adjacent messages of the first message, synchronization can be realized based on the third indication information, so that synchronization between the first message and the adjacent messages of the first message is not required through an Inter Packet Gap (IPG), the Ethernet message transmission mode without placing the IPG is realized, and meanwhile, the bearing efficiency of effective data in the message can be further improved, and the communication efficiency is improved.

S103, the second node determines a preamble of the first message based on the synchronous signaling, and determines a source MAC address of the first message based on the curID of the PLCA corresponding to the first message.

In this embodiment, after the second node receives the first message in step S102, the second node determines the preamble of the first message based on the synchronization signaling in step S103, and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message.

In one possible implementation manner, the process of determining, by the second node, the preamble of the first packet based on the synchronization signaling and determining, by the second node, the source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet in step S103 includes: when the second node determines that the first message is legal based on the curID of the PLCA corresponding to the first message, the second node determines the preamble of the first message based on the synchronous signaling, and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message.

Specifically, in the process that the second node determines the preamble of the first message based on the synchronization signaling and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message, the second node may first determine that the first message is a legal message based on the curID of the PLCA corresponding to the first message, and then parse the first message, that is, the second node determines the preamble of the first message based on the synchronization signaling and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message. Therefore, in the process of receiving the first message based on the PLCA mechanism, the second node receives (or analyzes) the interested message by filtering the curID of the PLCA corresponding to the received message, and does not need to receive (or analyze) all the messages, so that unnecessary expenditure is avoided.

In addition, the destination MAC address of the first packet is a broadcast address, a multicast address of a multicast group where the second node is located, or a unicast address of the second node. Specifically, the second node can receive (or parse) the first message, and the MAC address of the second node is the destination MAC address of the first message. Therefore, in the transmission process of the ethernet message, the overhead can be saved by avoiding sending the destination MAC address of the message, and meanwhile, the bearing efficiency of the effective data in the message is further improved, so as to improve the communication efficiency.

Illustratively, the implementation of PLCA node data message source-free MAC address transmission may be described as an example shown in fig. 7. In fig. 7, the PLCA bus nodes are all sent in the order of the set ID sizes within the transmission period (Transmission Cycle, TC) specified by the Master node. The ID of each node is unique within the bus (e.g., in fig. 7, the "curid=0" when CurID is 0, and the "curid=1" when CurID is 1). In the transmission period, a local variable CurID is maintained in each node and used for identifying the ID of the current transmitting node, and the CurID is updated in real time through bus signaling, so that the CurID of all nodes is identical under the condition that the bus works normally. The innovation point of this embodiment is that the source MAC address of the current transmitting node is identified by the CurID of the bus synchronization, so that the source node need not contain the source MAC address when transmitting the ethernet frame. If the receiving end is a bus node, the receiving node can identify the source MAC address of the currently transmitted data through the CurID. The correspondence between MAC addresses and IDs may be implemented by a correspondence table. As shown in table 1, the mapping table may be preconfigured, or may be learned, and the specific configuration mode of the mapping table is not limited in the present application.

TABLE 1

PLCA Node ID	MAC Address
		0	AA:BB:CC:DD:EE:FF
1	AA:BB:CC:DD:EE:FE
		2	AA:BB:CC:DD:EE:FD

Based on the above implementation procedure, the data packet (e.g., the first packet) does not include source MAC address information when sent by the physical layer, and the receiving Node (e.g., the second Node) recovers the source MAC of the received packet through the table of local PLCA Node IDs and MAC addresses.

Illustratively, the implementation of the PLCA node data message destination MAC address free transmission can be described as illustrated in the example of fig. 8. In fig. 8, when a bus node transmits data, other nodes on the bus can receive the data, and the physical communication mechanism is a broadcast communication mechanism. To save bandwidth very much, data unicast can be implemented by setting a reception Filter at the receiving end. As shown in fig. 8, node a sends a data message to node B, the message not containing the destination MAC. The message is received by all nodes on the bus, but the received node discards the message since the local Filter is not configured to receive the message from node a. Node B is configured to receive filters and to accept data from node a so that node B can successfully receive unicast messages sent by a. In addition, the multicast message sending mechanism can be controlled by a Master node. For example, at the beginning of a transmission cycle, the Master node notifies all bus nodes to transmit data of a certain destination address by broadcasting transmission signaling. The Master node obtains all multicast addresses to be sent of the current bus node through configuration, and the data sending destination address is precisely controlled by polling different multicast addresses at different Transmission cycle.

In one possible implementation, the first message further includes a payload and first cyclic redundancy check, CRC, information, the first CRC information being generated based on the payload. Specifically, the first packet received by the second node in step S102 further includes payload and first CRC information, and the first CRC is generated at least based on the payload, so that the second node checks the payload included in the first packet based on the first CRC information, so as to improve the security of ethernet packet transmission.

Optionally, the first packet further includes a VLAN tag and an ethernet type ethernet, and the first CRC information is generated based on the VLAN tag, the ethernet type and the payload; the method further comprises the steps of: when the second node determines that the first CRC information is successfully checked, the second node updates the first CRC information into second CRC information, wherein the second CRC information is generated based on a source MAC address of the first message, a destination MAC address of the first message, the VLAN tag, the ETHERTYPE and the payload.

Specifically, the first packet received by the second node in step S102 further includes a VLAN tag and an ethernet, and the first CRC information is generated based on at least the VLAN tag, the ethernet and the payload, so that the second node checks the VLAN tag, the ethernet and the payload included in the first packet based on the first CRC information, so as to further improve the security of ethernet packet transmission. In addition, the second node may update the first CRC information to second CRC information when it is determined that the first CRC information check is successful, where the second CRC information is generated based on a source MAC address of the first packet, a destination MAC address of the first packet, the VLAN tag, the ethernet type, and the payload, so as to be compatible with a CRC check manner in an existing ethernet network.

As shown in fig. 9, a transmission flow chart of the first node transmitting the first message in step S102 may include the following steps:

A1. is the first node determining whether it is a data communication within the PLCA bus? If yes, step A2 is executed, if no, step A1 is repeatedly executed, for example, determining whether the next communication is a data communication in the PLCA bus?

A2. The first node encapsulates a first message, and the first message includes a VLAN tag, an ethertype and a payload. The step is used for realizing address free (address free) message transmission in the PLCA bus communication process.

A3. The first node generates a CRC.

A4. Is the first node determining whether it currently belongs to its own transmission window? If yes, step A5 is executed, if no, step A4 is repeatedly executed, for example, it is determined whether the next time belongs to the own transmission window? In other words, the first node needs to transmit data in the term own transmission window when transmitting PLCA data.

A5. The first node transmits a compressed ethernet message.

It should be understood that, in step A5, "compressed ethernet packet" refers to a first packet, and "compressed" refers to a first packet sent by a first node that is free from sending a preamble, a source MAC address, a destination MAC address, and the like, compared to other ethernet packets.

As can be seen from the implementation example shown in fig. 9, in the process of sending a message, if the message is intra-bus communication, the sending end implements a message compression scheme, and sends a omitting preamble, a source MAC address, a destination MAC address and an IPG. Generating a CRC over VLAN TAG, ETHERTYPE, PAYLOAD (whereas ethernet packets also typically require generating a CRC based on the source MAC address as well as the destination MAC address). And the transmitting node waits for its own transmitting window in the current transmitting period and transmits the compressed message. If the receiving node is an off-bus node, the message needs to contain a destination MAC address to identify. The preamble, source MAC and IPG may be omitted. And is restored by a Master node and transmitted in a wide area network.

In one possible implementation, the first message further includes first indication information, where the first indication information is used to indicate a message type of the first message, where the message type includes a high priority message, a preempted message, or an initial fragment of a message. Specifically, the existing ethernet standard support messages implement a priority preemption mechanism by combining a preamble and an SMD, and in order to be compatible with the preemption mechanism, if a first message sent by a first node does not include the preamble, the first message may further include first indication information for indicating a message type of the first message. Therefore, under the condition that the first message does not carry the preamble, the indication of the message type of the first message is realized through the first indication information carried by the first message, and the existing Ethernet standard is compatible.

Illustratively, the Ethernet standard IEEE 802.3BR supports a priority preemption mechanism between messages. The high priority message and the preempted low priority message are identified by the preamble. As shown in fig. 10, a high priority packet (express packet), a preempted packet (a complete preemptable packet), or an initial fragment (an intial fragment of a packet) of a packet is identified by an "SMD"; as shown in fig. 11, the subsequent fragmentation message format of a message is identified by "SMD" and "fragment number (frag_count)".

In order to be compatible with the existing 802.3BR data format, the first indication information is defined as a new message format identifier, for example, the first indication information can be expressed as a MAC header indication (MAC header indicator, MHI), and the hamming distance is maintained, so as to ensure the current balance of the transmission line and avoid electromagnetic interference caused by excessive continuous transmission of "0" or "1".

Alternatively, as shown in fig. 12, the first indication information indicates a high priority packet (express packet) with a value of "0xE6", and the value may indicate a frame type broadcast mode (frame type broadcast mode, FT-BM).

Alternatively, as shown in fig. 12, the first indication information indicates an initial slice (an intial fragment of a packet) of one message, and the value "0x4c" may indicate a frame type broadcast mode initial slice (frame type broadcast mode initial fragment, FT-BM-IF).

Alternatively, as shown in fig. 12, the first indication information indicates a subsequent slice (continuation fragment) of one message, and the value "0x7F" may indicate a frame type broadcast mode subsequent slice (frame type broadcast mode continuation fragment, FT-BM-CF).

Alternatively, for Express Packet/Complete Packet, the SFD/SMD value is replaced with the FT-BM value.

Optionally, the FT-BM-IF identification is added before the SMD for the initial message of the preempted message.

Optionally, for the subsequent messages of the preempted message, the FT-BM-CF identification is added before the SMD and the fragment count.

Therefore, in the process of receiving the message, IF the first indication information (namely FT-BM, FT-MB-IF or FT-BM-CF) exists in the message, the receiving end considers the received data as a compressed message and resumes the process when in subsequent processing, otherwise, the process is performed according to the standard message format.

For example, the receiving process of the first message by the second node in step S102 and the processing process of the first message by the second node in step S103 may be as shown in fig. 13, and include the following steps:

B1. the second node determines whether the identifier of the received packet carries the first indication information, that is, determines "sfd= =ft-BM", if yes, step B2 is executed, and if not, a standard frame processing procedure is executed (standard frame process).

B2. The second node determines the ID of the transmitting node according to the CurID when the message is received. That is, the second node determines the Source MAC Address (SMAC) of the message through the PLCA network's current transmission window correspondence ID.

B3. And the second node judges whether the CRC check is passed, if so, the step B4 is executed, and if not, the message (drop packet) is discarded.

B4. The second node determines whether the ID passes through the filtering table, if yes, step B5 is executed, and if no, the packet (drop packet) is discarded. I.e. the second node acknowledges whether the message was received.

B5. The SMAC and DMAC of the message are restored and the CRC is recalculated. I.e. the second node implements MAC layer message reduction.

B6. And the second node sends the message to the MAC layer for processing.

In one possible implementation manner, the determining the source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet includes: the method comprises the steps that a source MAC address of a first message is determined based on a mapping relation between a PLCA node ID indicated by a curID of the PLCA corresponding to the first message and a preset; or determining the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID indicated by the curID of the PLCA corresponding to the first message, wherein other fields of the source MAC address of the first message are preconfigured.

In an implementation example, taking an implementation process that the second node determines the source MAC address of the first packet based on the PLCA node ID and a preset mapping relationship after determining the PLCA node ID corresponding to the first node as an example. In order to be able to recover the source MAC address of the received compressed message, a node ID-MAC address mapping table is configured at each node. The entries are shown in fig. 14. And associating the CurID with the MAC address of the corresponding transmitting Ethernet node, and when receiving the compressed message, checking the corresponding MAC address through the current CurID. In other words, each node configures an ID filter table (ACL) for filtering received irrelevant messages by CurID.

In another implementation example, after determining the PLCA node ID corresponding to the first node, the second node determines the value of a part of fields of the source MAC address of the first packet based on the value of the PLCA node ID, and the other fields of the source MAC address of the first packet are preconfigured implementation processes. As shown in fig. 15, the MAC address of the source node may include six bytes (denoted as "6-octets") as in 15, including a first byte (denoted as "1 st-octet"), a second byte (denoted as "2 nd-octet"), a third byte (denoted as "3 rd-octet"), a fourth byte (denoted as "4 th-octet"), a fifth byte (denoted as "5 th-octet"), and a sixth byte (denoted as "6 th-octet"). Wherein, the value of the first three bytes can be an organization unique identifier (organization unique identity, OUI), or referred to as an organization specific ID, and each node is preconfigured; the value of any two bytes in the last three bytes is the related information of the network card, and can be recorded as the details (network interface controller specific, NIC specific) of the network interface controller; the value of the other byte in the last three bytes is the PLCA node ID corresponding to the first message (or CurID corresponding to the first message).

For example, as shown in fig. 16, the "NIC specific" is uniformly allocated to ensure that the in-vehicle network is unique, and the last byte in the last three bytes is assigned by the PLCA node ID corresponding to the first message (or the CurID corresponding to the first message).

Alternatively, the second indication information for indicating the transmission type of the first message may be implemented at a different value of the last two bits in "1st otte" in fig. 15. For example, in fig. 15, a value of 0 for the last bit "b0" indicates unicast (unicast), and a value of 1 indicates multicast (multicast), wherein multicast includes multicast or broadcast. The value of the next to last bit "b1" is 0, which indicates a globally unique identifier (OUI establishment), and the value of 1, which indicates local management (locally administered).

It should be understood that six bytes in fig. 15 may also be denoted as "B5 to B0", respectively, wherein the first byte (denoted as "1st octet", corresponding to "B5"), the second byte (denoted as "2nd octet", corresponding to "B4"), the third byte (denoted as "3rd octet", corresponding to "B3"), the fourth byte (denoted as "4th octet", corresponding to "B2"), the fifth byte (denoted as "5th octet", corresponding to "B1"), and the sixth byte (denoted as "6th octet", corresponding to "B0").

Alternatively, for the "NIC specific" field, it may be configured as 10BaseT1S channel ID, ensuring that the whole network is unique within the range of the IVN.

Taking the implementation of fig. 15 as an example, for the SMAC restore process:

1. the second node determines that B5.b1 in the standard MAC address structure is assigned 1, and marks the address as a local management address;

2. the second node assigns B5.b0 in the standard MAC address structure to 0, and confirms that the address is a unicast address;

3. the second node assigns B0 within the standard MAC address structure as the PLCA node ID (aPLCALocalNodeID) of the first node.

For the DMAC reduction process:

1. if the data is received by the broadcast mechanism, the second node reverts the DMAC to the broadcast MAC address ff: ff: ff: ff;

2. if the data is received through the multicast mechanism, the second node restores the DMAC to the current corresponding multicast address;

3. otherwise, the second node restores the DMAC to unicast and takes the local MAC address of the second node as the address of the message DMAC.

Specifically, in the process of sending the first message by the first node based on the PLCA mechanism, the first message may further include third indication information for indicating a message sending state of the first message, where the third indication information is located after the payload in the first message. Therefore, after the receiving side of the first message receives the first message and the adjacent messages of the first message, synchronization can be realized based on the third indication information, so that synchronization between the first message and the adjacent messages of the first message is not required through an Inter Packet Gap (IPG), the Ethernet message transmission mode without placing the IPG is realized, and meanwhile, the bearing efficiency of effective data in the message can be further improved, and the communication efficiency is improved.

An implementation process shown in fig. 17 is exemplified. Before the PLCA bus node sends data, four symbols (symbols) of SYNC1, SYNC2, SSD1, SSD2 are sent to the bus to synchronize other nodes on the bus, that is, the synchronization signaling in the first message may include "four symbols of SYNC1, SYNC2, SSD1, SSD 2". And after receiving the four symbols, other nodes on the bus consider that new message data starts to be sent. The transmit state machine enters the DATA state to transmit DATA, and these four symbols can replace the first two bytes in the ethernet seven-byte preamble, as specified by the IEEE standard. The five byte preamble and the last 12 byte IPG of the message are then sent in the DATA state. After the data frame is sent, the sending node informs other nodes on the bus of the data sending state. If the transmission is successful, esd+good_ ESD (End of Stream Delimiter) is transmitted, otherwise esd+bad_esd is transmitted, as shown in fig. 16, the transmitting node already displays transmission synchronization information before and after transmitting the data frame, without synchronizing the preamble defined by the ethernet message with the IGP. In summary, the transmission of the preamble (last five bytes) and IPG (12 bytes) may be omitted within the PLCA network.

Optionally, each byte of the last five bytes of the preamble has a value of "0x55", the IPG is a 12-byte transmission time, typically a null (IDLE), and for a PLCA bus node (e.g., the first node or the second node) it is silent and no data is sent.

Based on the above technical solution, in the ethernet communication process, the first node is used as a message sender, and the synchronization signaling included in the first message sent by the first node in step S102 is used to determine the preamble of the first message, and the curID of the PLCA corresponding to the first message sent by the first node is used to determine the source MAC address of the first message. That is, after the receiving side (i.e., the second node) of the first packet receives the first packet, the second node may determine the preamble of the first packet based on the synchronization signaling included in the first packet and determine the source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet in step S103. In other words, in the method, when the first message sent by the first node does not carry the preamble of the first message and the source MAC address of the first message, the receiver of the first message may determine the preamble of the first message and the source MAC address of the first message. Therefore, in the transmission process of the Ethernet message, the method is used for saving the cost by avoiding sending the preamble of the message and the source MAC address of the message, and improving the bearing efficiency of effective data in the message so as to improve the communication efficiency.

The embodiments of the present application are described above in terms of methods, and the communication device provided by the embodiments of the present application is described below in terms of devices.

Referring to fig. 18, an embodiment of the present application provides a communication device 1800 that can implement the functions of the communication device in the above method embodiment, and thus can also implement the advantages of the above method embodiment.

The communication device 1800 includes a processing unit 1801 and a transceiver unit 1802.

When the communication device 1800 implements the implementation procedure corresponding to the first node in any of the foregoing embodiments, the processing unit 1801 is configured to determine a first packet, where the first packet includes synchronization signaling, and the synchronization signaling is used to determine a preamble of the first packet; the transceiver 1802 is configured to send the first packet, where a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first packet is used to determine a source MAC address of the first packet.

In one possible implementation, the first message further includes a payload and first cyclic redundancy check, CRC, information, the first CRC information being generated based on the payload.

In one possible implementation, the first packet further includes a VLAN tag and an ethernet type ethernet, and the first CRC information is generated based on the VLAN tag, the ethernet and the payload.

In one possible implementation, the first message further includes first indication information, where the first indication information is used to indicate a message type of the first message, where the message type includes a high priority message, a preempted message, or an initial fragment of a message.

In one possible implementation, the first packet further includes second indication information, where the second indication information is used to indicate a transmission type of the first packet, and the transmission type includes broadcast, multicast, or unicast.

In one possible implementation, the transmission period of the first packet is used to indicate a transmission type of the first packet and/or a destination MAC address of the first packet, where the transmission type includes broadcast, multicast or unicast.

In one possible implementation manner, the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes: the curID of the PLCA corresponding to the first message is used for indicating the PLCA node ID; the mapping relation between the PLCA node ID and the preset mapping relation is used for determining the source MAC address of the first message; or, the PLCA node ID is a value of a part of fields of the source MAC address of the first packet, and other fields of the source MAC address of the first packet are preconfigured.

In one possible implementation, the length of the first message is less than 64 bytes.

When the communication device 1800 implements the implementation procedure corresponding to the second node in any of the foregoing embodiments, the transceiver 1802 is configured to receive a first packet, where the first packet includes synchronization signaling; the processing unit 1801 is configured to determine a preamble of the first packet based on the synchronization signaling, and determine a source MAC address of the first packet based on a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first packet.

In one possible implementation, the first packet further includes a VLAN tag and an ethernet type ethernet, and the first CRC information is generated based on the VLAN tag, the ethernet type and the payload; the processing unit 1801 is further configured to update the first CRC information to second CRC information when it is determined that the first CRC information check is successful, where the second CRC information is generated based on a source MAC address of the first packet, a destination MAC address of the first packet, the VLAN tag, the ethernet type, and the payload.

In one possible implementation, the destination MAC address of the first packet is a broadcast address, a multicast address of a multicast group in which the second node is located, or a unicast address of the second node.

In one possible implementation manner, when determining that the first packet is a legal packet based on the curID of the PLCA corresponding to the first packet, the processing unit 1801 determines a preamble of the first packet based on the synchronization signaling, and determines a source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet.

In one possible implementation, the processing unit 1801 is specifically configured to: the method comprises the steps that a source MAC address of a first message is determined based on a mapping relation between a PLCA node ID indicated by a curID of the PLCA corresponding to the first message and a preset; or determining the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID indicated by the curID of the PLCA corresponding to the first message, wherein other fields of the source MAC address of the first message are preconfigured.

It should be noted that, for the content of the information execution process of each unit of the communication device 1800, reference may be specifically made to the description in the foregoing method embodiment of the present application, and the details are not repeated here.

The embodiment of the application also provides a communication device 1900, referring to fig. 19, and fig. 19 is a schematic structural diagram of the communication device 1900 according to the embodiment of the application.

Optionally, the communications apparatus 1900 performs the functions of the communications apparatus of any of the previous embodiments (e.g., the first node, the second node, etc. in the implementation shown in fig. 6).

Alternatively, the communication device 2000 of fig. 19 may be used to perform the functions of other communication devices. For example, where the communications apparatus 1900 is a first node, the communications apparatus 2000 can be configured to perform the functions of a second node; as another example, where communications apparatus 1900 is a second node, communications apparatus 2000 can be configured to perform the functions of a first node.

The communications device 1900 of fig. 19 includes a memory 1902 and at least one processor 1901.

Alternatively, the processor 1901 may implement the method in the above embodiment by reading the instructions stored in the memory 1902, or the processor 1901 may implement the method in the above embodiment by means of the instructions stored internally. In the case where the processor 1901 implements the method in the above embodiment by reading the instructions held in the memory 1902, the instructions for implementing the method provided in the above embodiment of the present application are held in the memory 1902.

Optionally, at least one processor 1901 is one or more CPUs, or is a single-core CPU, or may be a multi-core CPU.

Memory 1902 includes, but is not limited to, RAM, ROM, EPROM, flash memory, or optical memory, among others. The memory 1902 stores instructions of an operating system.

After the program instructions stored in the memory 1902 are read by the at least one processor 1901, the communication device performs the corresponding operations in the foregoing embodiments.

Optionally, the communication device shown in fig. 19 further includes a network interface 1903. The network interface 1903 may be a wired interface, such as an FDDI, GE interface; the network interface 1903 may also be a wireless interface. The network interface 1903 is used to receive reception/transmission data in the foregoing embodiment.

After the processor 1901 reads the program instructions in the memory 1902, the other functions that the communication device 1900 can perform are described in the foregoing method embodiments.

Optionally, the communications device 1900 further includes a bus 1904, and the processor 1901 and the memory 1902 are typically coupled to each other via the bus 1904, but may be coupled to each other in other manners.

Optionally, the communications apparatus 1900 further includes an input/output interface 1905, where the input/output interface 1905 is configured to connect to an input device, and receive relevant configuration information (such as a value of m, a value of n, a time domain length corresponding to the third time domain position, a time domain length corresponding to the fourth time domain position, etc.) input by a user or other devices capable of linking with the communications apparatus 1900 through the input device. Input devices include, but are not limited to, a keyboard, touch screen, microphone, and the like.

The communication device 1900 provided by the embodiment of the application is used for executing the method executed by the communication device provided by each method embodiment and realizing the corresponding beneficial effects.

Illustratively, where the communications apparatus 1900 is a first node, the communications apparatus 2000 can be configured to perform the function of a second node, the communications apparatus 1900 determines a first message including synchronization signaling for determining a preamble of the first message; the communication device 1900 sends the first message, where the curID of the PLCA corresponding to the first message is used to determine the source MAC address of the first message.

Thus, in the ethernet communication process, the communication device 1900 is used as a message sender, and the synchronization signaling included in the first message sent by the communication device 1900 is used to determine the preamble of the first message, and the curID of the PLCA corresponding to the first message sent by the communication device 1900 is used to determine the source MAC address of the first message. That is, after receiving the first packet, the communication device 2000 may determine the preamble of the first packet based on the synchronization signaling included in the first packet and determine the source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet. In other words, in this method, when the first message sent by the communication apparatus 1900 does not carry the preamble of the first message and the source MAC address of the first message, the communication apparatus 2000 may be caused to determine the preamble of the first message and the source MAC address of the first message. Therefore, in the transmission process of the Ethernet message, the method is used for saving the cost by avoiding sending the preamble of the message and the source MAC address of the message, and improving the bearing efficiency of effective data in the message so as to improve the communication efficiency.

For example, where the communications apparatus 1900 is a second node, the communications apparatus 2000 can be configured to perform the functions of the first node. The communications device 1900 receives a first message comprising synchronization signaling; the communication device 1900 determines a preamble of the first message based on the synchronization signaling, and determines a source MAC address of the first message based on a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first message.

Thus, in the ethernet communication process, the communication device 1900 is used as a message receiving side, the synchronization signaling included in the first message received by the communication device 1900 is used to determine the preamble of the first message, and the curID of the PLCA corresponding to the first message sent by the communication device 2000 is used to determine the source MAC address of the first message. That is, after receiving the first packet, the communication device 1900 may determine the preamble of the first packet based on the synchronization signaling included in the first packet and determine the source MAC address of the first packet based on the curID of the PLCA corresponding to the first packet. In other words, in this method, when the first message sent by the communication device 2000 does not carry the preamble of the first message and the source MAC address of the first message, the receiver of the first message may determine the preamble of the first message and the source MAC address of the first message. Therefore, in the transmission process of the Ethernet message, the method is used for saving the cost by avoiding sending the preamble of the message and the source MAC address of the message, and improving the bearing efficiency of effective data in the message so as to improve the communication efficiency.

The specific implementation of the communication apparatus 1900 shown in fig. 19 may refer to the descriptions in the foregoing method embodiments, and achieve corresponding technical effects, which are not described herein in detail.

In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. A method of communication, comprising:

the method comprises the steps that a first node determines a first message, wherein the first message comprises synchronous signaling, and the synchronous signaling is used for determining a preamble of the first message;

the first node sends the first message, and the current identifier curID of the physical layer collision avoidance mechanism PLCA corresponding to the first message is used for determining the source media access control MAC address of the first message.

2. The method of claim 1, wherein the first message further comprises a payload and first cyclic redundancy check, CRC, information, the first CRC information generated based on the payload.

3. The method of claim 2, wherein the first message further comprises a virtual local area network tag VLAN tag and an ethernet type ethernet, and wherein the first CRC information is generated based on the VLAN tag, the ethernet type and the payload.

4. A method according to any one of claims 1 to 3, wherein the first message further comprises first indication information, the first indication information being used to indicate a message type of the first message, the message type comprising a high priority message, a preempted message or an initial fragment of a message.

5. The method according to any one of claims 1 to 4, wherein the first message further comprises second indication information, the second indication information being used to indicate a transmission type of the first message, the transmission type comprising broadcast, multicast or unicast.

6. The method according to any one of claims 1 to 4, wherein a transmission period of the first message is used to indicate a transmission type of the first message and/or a destination MAC address of the first message, and the transmission type includes broadcast, multicast or unicast.

7. The method according to any one of claims 1 to 6, wherein the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes:

the curID of the PLCA corresponding to the first message is used for indicating the PLCA node ID;

the mapping relation between the PLCA node ID and a preset map is used for determining a source MAC address of the first message; or, the value of the PLCA node ID is the value of a part of fields of the source MAC address of the first packet, and other fields of the source MAC address of the first packet are preconfigured.

8. The method according to any one of claims 1 to 7, wherein,

The length of the first message is smaller than 64 bytes.

9. The method according to any one of claims 1 to 8, wherein the first message further includes third indication information, the third indication information being used for indicating a message sending status of the first message, and the third indication information being used for separating adjacent messages of the first message from the first message.

10. A method of communication, comprising:

the second node receives a first message, wherein the first message comprises synchronous signaling;

and the second node determines a preamble of the first message based on the synchronous signaling, and determines a source Media Access Control (MAC) address of the first message based on a current identifier curID of a physical layer collision-free mechanism (PLCA) corresponding to the first message.

11. The method of claim 10, wherein the first message further comprises a payload and first cyclic redundancy check, CRC, information, the first CRC information generated based on the payload.

12. The method of claim 11, wherein the first message further comprises a virtual local area network tag VLAN tag and an ethernet type ethernet, the first CRC information being generated based on the VLAN tag, the ethernet type and the payload;

The method further comprises the steps of:

and when the second node determines that the first CRC information is successfully checked, the second node updates the first CRC information into second CRC information, wherein the second CRC information is generated based on a source MAC address of the first message, a destination MAC address of the first message, the VLAN tag, the ETHERTYPE and the payload.

13. The method according to any one of claims 10 to 12, wherein the destination MAC address of the first message is a broadcast address, a multicast address of a multicast group in which the second node is located, or a unicast address of the second node.

14. The method according to any one of claims 10 to 13, wherein the second node determining the preamble of the first message based on the synchronization signaling and determining the source MAC address of the first message based on the curID of the PLCA to which the first message corresponds comprises:

and when the second node determines that the first message is legal based on the curID of the PLCA corresponding to the first message, the second node determines the preamble of the first message based on the synchronous signaling and determines the source MAC address of the first message based on the curID of the PLCA corresponding to the first message.

15. The method according to any one of claims 10 to 14, wherein the first message further comprises first indication information, the first indication information being used to indicate a message type of the first message, the message type comprising a high priority message, a preempted message or an initial fragment of a message.

16. The method according to any one of claims 10 to 15, wherein the first message further comprises second indication information, the second indication information being used to indicate a transmission type of the first message, the transmission type comprising broadcast, multicast or unicast.

17. The method according to any one of claims 10 to 15, wherein a transmission period in which the first message is located is used to indicate a transmission type of the first message and/or a destination MAC address of the first message, where the transmission type includes broadcast, multicast or unicast.

18. The method according to any one of claims 10 to 17, wherein the determining the source MAC address of the first message based on the curID of the PLCA to which the first message corresponds comprises:

the mapping relation between the PLCA node ID indicated by the curID of the PLCA corresponding to the first message and a preset is used for determining a source MAC address of the first message;

Or alternatively, the first and second heat exchangers may be,

and determining the value of a part of fields of the source MAC address of the first message based on the value of the PLCA node ID indicated by the curID of the PLCA corresponding to the first message, wherein other fields of the source MAC address of the first message are preconfigured.

19. The method according to any one of claims 10 to 18, wherein,

the length of the first message is smaller than 64 bytes.

20. The method according to any one of claims 10 to 19, wherein the first message further includes third indication information, the third indication information being used to indicate a message sending status of the first message, and the third indication information being used to separate adjacent messages of the first message from the first message.

21. A communication device, comprising a processing unit and a transceiver unit;

the receiving and transmitting unit is configured to send the first packet, where a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first packet is used to determine a source medium access control MAC address of the first packet.

22. The apparatus of claim 21, wherein the first message further comprises a payload and first cyclic redundancy check, CRC, information, the first CRC information generated based on the payload.

23. The apparatus of claim 22, wherein the first message further comprises a virtual local area network tag and an ethernet type ethernet, and wherein the first CRC information is generated based on the VLAN tag, the ethernet and the payload.

24. The apparatus according to any one of claims 21 to 23, wherein the first message further comprises first indication information, the first indication information being used to indicate a message type of the first message, the message type comprising a high priority message, a preempted message or an initial fragment of a message.

25. The apparatus according to any one of claims 21 to 24, wherein the first message further comprises second indication information, the second indication information being used to indicate a transmission type of the first message, the transmission type comprising broadcast, multicast or unicast.

26. The apparatus according to any one of claims 21 to 24, wherein a transmission period in which the first message is located is used to indicate a transmission type of the first message and/or a destination MAC address of the first message, where the transmission type includes broadcast, multicast or unicast.

27. The apparatus of any one of claims 21 to 26, wherein the determining, by the curID of the PLCA corresponding to the first packet, the source MAC address of the first packet includes:

28. The device according to any one of claims 21 to 27, wherein,

the length of the first message is smaller than 64 bytes.

29. The apparatus according to any one of claims 21 to 28, wherein the first message further includes third indication information, the third indication information being used to indicate a message sending status of the first message, and the third indication information being used to separate adjacent messages of the first message from the first message.

30. A communication device, comprising a processing unit and a transceiver unit;

The processing unit is configured to determine, based on the synchronization signaling, a preamble of the first message, and determine, based on a current identifier curID of a physical layer collision avoidance mechanism PLCA corresponding to the first message, a source medium access control MAC address of the first message.

31. The apparatus of claim 30, wherein the first message further comprises a payload and first cyclic redundancy check, CRC, information, the first CRC information generated based on the payload.

32. The apparatus of claim 31, wherein the first message further comprises a virtual local area network tag VLAN tag and an ethernet type ethernet, the first CRC information being generated based on the VLAN tag, the ethernet type and the payload;

the processing unit is further configured to update the first CRC information to second CRC information when the first CRC information check is determined to be successful, where the second CRC information is generated based on a source MAC address of the first packet, a destination MAC address of the first packet, the VLAN tag, the ethernet type, and the payload.

33. The apparatus according to any one of claims 30 to 32, wherein the destination MAC address of the first message is a broadcast address, a multicast address of a multicast group in which the second node is located, or a unicast address of the second node.

34. The apparatus according to any one of claims 30 to 33, wherein the processing unit determines, when determining that the first message is a legitimate message based on a curID of a PLCA to which the first message corresponds, a preamble of the first message based on the synchronization signaling, and determines a source MAC address of the first message based on the curID of the PLCA to which the first message corresponds.

35. The apparatus according to any one of claims 30 to 34, wherein the first message further comprises first indication information, the first indication information being used to indicate a message type of the first message, the message type comprising a high priority message, a preempted message or an initial fragment of a message.

36. The apparatus according to any one of claims 30 to 35, wherein the first message further comprises second indication information, the second indication information being used to indicate a transmission type of the first message, the transmission type comprising broadcast, multicast or unicast.

37. The apparatus according to any one of claims 30 to 35, wherein a transmission period in which the first message is located is used to indicate a transmission type of the first message and/or a destination MAC address of the first message, where the transmission type includes broadcast, multicast or unicast.

38. The device according to any one of claims 30 to 37, wherein the processing unit is specifically configured to:

or alternatively, the first and second heat exchangers may be,

39. The device according to any one of claims 30 to 38, wherein,

the length of the first message is smaller than 64 bytes.

40. The apparatus of any one of claims 30 to 39, wherein the first message further includes third indication information, the third indication information being used to indicate a message sending status of the first message, the third indication information being used to separate adjacent messages of the first message from the first message.

41. A communication device comprising at least one processor, and a memory coupled to the at least one processor;

the memory is used for storing programs or instructions;

The at least one processor is configured to execute the program or instructions to cause the communication device to implement the method of any one of claims 1 to 20.

42. A computer readable storage medium comprising a program or instructions which, when run on a computer, cause the method of any one of claims 1 to 20 to be performed.