Evaluation And Optimization Of The Transmission Of Hybrid Traffic In Vanet

As the society moves forward and the economy becomes flourished, the number of vehicles steadily grows, especially the number of family cars. Along with the increasing number of automobiles, many problems come out among which traffic congestions and road safety are most significant. Therefore, Intelligent Transport System (ITS) is proposed to tackle these problems. Vehicular Ad-hoc NETwork (VAENT) is a very important part of ITS. VANET can realize the information exchange among vehicles and enhance road safety; it can also provide Internet access for passengers to give them on board entertainment. Currently, the main telecommunication technology for VANET is the WAVE protocol stacks proposed by the Institute of Electrical and Electronic Engineers (IEEE). This protocol is very typical for vehicular communication system and attracts a lot of research interests. Many VANET researches are based on this protocol.In this thesis, first comes a brief introduction of the current research and development of VANET with a focus on the Media Access Control (MAC) mechanism of WAVE and challenges in MAC design. Then the simulation system analysis and design is presented to conduct the evaluation of the performance of VANET carrying hybrid traffic. Next the definitions of hybrid traffic and the models of each type of traffic in VANET based on the analysis on current network traffic data are given. The performance of IEEE802.11p carrying hybrid traffic is then proposed, i.e. the ability of current standards supporting hybrid traffic. Faced with the insufficiency of IEEE802.11p carrying hybrid traffic, a new distributed TDMA MAC mechanism, CFR MAC, is then proposed. Evaluated by the VANET simulation platform developed by this thesis, it is safe to conclude that CFR MAC has a better overall performance than the IEEE802.11p MAC and can better support hybrid traffic in VANET.