Research And Implementation Of The LLC Layer Of The WAVE Protocol And The SAE J2735 Protocol

WAVE-vehicle wireless communication technology have these three characteristics in practical applications:frequent link disconnection and reconnection, high dynamic space-time traffic conditions, data dissemination heterogeneity. Although the traditional LLC protocol has good portability, it can be apply in WAVE protocol and coupled thereto, but in the safety car networking scene in the special requirements and it can not be fully guaranteed.Therefore, this article uses the basic safety messages associated with SAE J2735 standard which is proposed by application layer, based on the WAVE environment LLC layer for high spatial and temporal dynamic multi-node traffic safety scenarios for data transmission research and improvement. This paper first analyzed communication mode and temporal characteristics of high dynamic traffic scenarios, analyzed functional requirements of these levels, including the construction of transmitted and received packets send and receive, format conversion, data frame processing, error checking and error handling, etc. Then improved the error control and handling algorithm of LLC layer in high-speed and multi-node environment, introduction and improvement of the CRC checking algorithm and selective ARQ controling algorithms, to meet the basic safety messages automotive environment features:high-speed and stability. Corresponding to design and implement other features for basic security messaging in LLC layer and the application layer, including the use of ASN.1 to achieve the conversion packet format, the data frame processing, encoding and decoding.Finally, test the improved algorithm and implementation with simulation platform, to ensure basic safety messaging capabilities in vehicle wireless network environment, and testing messaging during packet loss and network delay, respectively, to compare with the traditional and LLC layer non-secure transmission of information and draw conclusions:in this paper, the improved and achieved about WAVE LLC layer and basic safety message transmission, in high-speed scene, is better than the traditional LLC layer implementation.