Research Of Dedicated Short Range Communication Protocol Based On NS-3

Intelligent Transportation System (ITS),it is a kind of the new transport system for intelligence,socialization and information, using advanced information, communication, control and other new technology, to transform the traditional transmitted system. Through vehicle to vehicle and vehicle to infrastructure communication, VANET which is one of important parts of ITS can not only improve traffic security and efficiency but also provide entertainment for drivers. In VANET, DSRC (Dedicated Short Range Communication) is an efficient and dedicated communicative technology of wireless which can achieve accurate and reliable two-way transmission of voice, data and images within a small range, connecting the organic vehicle and infrastructure.Thus DSRC become an important communicative platform for ITS. Medium access protocol IEEE802.11p, which is used in the Dedicated Short Range Communication (DSRC), utilizes Enhanced Distribution Coordinate Access (EDCA) and prioritization to provide communicative guarantees. Vrhicle wireless communications systems based on IEEE802.11p as part of ITS will improve transport efficiency, real-time and safety.This paper describes the research content of the key technolohies of wirelesss communicateon systems in vehicles. IEEE802.11p, which is based on on-board self-organizing networks of wireless Ad Hoc networks for dedicated short range communication (DSRC) protocol, the agreement is used for a more in-depth study. Compared IEEE802.11p with the traditional wirelesss LAN technology, analysis the physical layer (PHY) and media access control layer (MAC) modifyed in IEEE802.11p standard.In this paper, I researched access principle, access mechanisms, performance simulation and performance improvement of IEEE802.11p on the platform based on NS-3network simulator. From three aspects that are the average pocket delay, pocket loss rate and throughput did simulation experiments and researched the differences between the protocol of IEEE802.11p and normal IEEE802.11and their advantages in the automotive environment. Through simulation experiments, studied that vehicle distance, vehicle speed and vehicle density have influences on the performance of IEEE802.11p protocol. And for problems that simulation experiments found, put forward some ideas that improved the protocol of IEEE802.11p and did a part of verification. Also pointed out some current exist problems and future research directions of IEEE802.11p in dedicated short-range communications applications.