Contention-based Time Division Multiple Access MAC Protocol in Vehicular Ad Hoc Networks

Abstract

The high speed of vehicle movement and fast change of network topology make it a challenge to design a reliable Medium Access Control(MAC) protocol to meet the low latency and high throughput requirements of Vehicular Ad Hoc Networks(VANETs).This paper proposes a contention-based Time Division Multiple Access(TDMA) MAC protocol.First,the road is segmented according to the communication radius of vehicles,and then the vehicles in each segment are organized to communicate in a periodic manner.Functionally,each communication period is divided into the static segment and dynamic segment.The former is used for communication by time division multiplexing,and the latter is used for competing for time slots of transmission in the static segment to newly added vehicles.Simulation results show that compared with the DTMAC protocol,this protocol can significantly improve the data transmission throughput,decrease the probability of collision between vehicles,and reduce the waiting time of data sent by newly added vehicles.