Introduction to the hierarchical structure of automotive Ethernet

Automotive Ethernet usually adopts the layered structure of the OSI (Open System Interconnection) model, which divides network communication into seven different layers, each responsible for different functions. The following is the layered structure of automotive Ethernet and its correspondence with the OSI model:

Application Layer:

Responsible for defining the rules for communication and data exchange between applications.

Used to realize data exchange in the vehicle application layer, such as in-vehicle entertainment systems, navigation systems, etc.

Presentation Layer:

Mainly responsible for data format conversion, encryption and compression to ensure data format compatibility between different devices.

In automotive Ethernet, it may be used for data encoding and decoding to facilitate communication between different systems.

Session Layer:

Manages and maintains sessions and connections for data transfer.

It can be used for connection management and status maintenance in vehicle networks.

Transport Layer:

Responsible for data segmentation, reorganization and error detection to ensure reliable data transmission.

In automotive Ethernet, it may be used for TCP (Transmission Control Protocol) or UDP (User Datagram Protocol) transmission to meet the needs of different applications.

Network Layer:

Responsible for data routing and addressing, ensuring that data can be transmitted correctly in the network.

IP (Internet Protocol) addressing and routing may be involved in automotive Ethernet.

Data Link Layer:

It is divided into two sublayers: Logical Link Control (LLC) sublayer and Medium Access Control (MAC) sublayer.

The MAC sublayer is responsible for frame assembly and parsing, as well as control of access to the physical media.

In automotive Ethernet, the Ethernet protocol is often used as the data link layer protocol.

Physical Layer:

Responsible for the actual physical signal transmission, including voltage, frequency, encoding method, etc.

In automotive Ethernet, the physical layer implements the electrical transmission of data, such as using twisted pair cables, optical fibers and other transmission media.

Simplified into the following five-layer hierarchical structure:

Someip, Someipsd, and Doip are located in the fifth layer of Ethernet application layer: Someip protocol, Someipsd protocol, and Doip protocol essentially stipulate the processing of data transmitted by the network layer and adapt to different application scenarios. In CP, Soad, SD, Doip, and Soemipxf are actually implementing application layer functions.