The Protocol Research Based On Onboard Ethernet

CAN bus network topology has been at the dominant position of automobile network technology. However, as the density of semiconductor materials and doubling the microprocessor computing ability, the strict limits for maximum bandwidth has restricted the development of the modern car bus. As more and more transmission theory and the protocol on the powerful function of Ethernet is developed, suppled and proved that the basic Ethernet as the LAN network can be seamlessly integrated, in line with the onboard Ethernet communication rules of the relevant agreements, the application compiled for the automotive developers form a huge industry standard, so the research for onboard Ethernet has become the urgent mission for most automotive electronics manufacturer. Cars in the next five to ten years, there will be more integration of different network segments, especially the onboard Ethernet will more be applied in the field of car, and will replace part of the existing bus system.In fully studied at home and abroad on the basis of related literature and data, contrast CAN bus the layered structure of communication protocol, transmission frame, and a message sent by the arbitration mechanism, further study of the 100 MBPS transmission rate and unshielded twisted pair of Ethernet interface layer, network layer, TCP/IP transport layer and application layer, this paper introduces the onboard Ethernet transmission frame structure form, a timing synchronization and addressing mode, etc., with its features such as scalability, flexibility, and low price is appliedin the automotive network.in order to validate the feasibility of the Ethernet in the on-board network application, this paper builds the compression and uncompression of the TCP/IP protocol data flow between modules, by MMI, IC, VECU, C2 XM and MMG modules of the simulation system, through the establishment of the database, the simulation panel and CAPL compiled language, meet the MMI, IC, VECU, C2 XM and MMG module communications requirements for reliability and real-time performance, prove the feasibility of this topic network design solution.