VeMAC Performance Evaluation for VANET Safety Applications

Abstract

This chapter investigates how the VeMAC protocol can deliver both periodic and event-driven safety messages in VANETs, by presenting a detailed delivery delay analysis, including queueing and service delays, for both types of safety messages [1, 2]. The probability mass function of the service delay is first derived, then the D/G/1 and M/G/1 queueing systems are used to calculate the average queueing delay of the periodic and event-driven safety messages respectively. As well, a comparison between the VeMAC protocol and the IEEE 802.11 p standard [3] is presented via extensive simulations using the network simulator ns-2 [4] and the microscopic vehicle traffic simulator VISSIM [5]. A real city scenario is considered and different performance metrics are evaluated, including the network goodput, protocol overhead, channel utilization, protocol fairness, probability of a transmission collision, and message delivery delay. Although the VeMAC is a multichannel protocol, this chapter focuses only on the operation of the VeMAC on the CCH, over which the high priority periodic and event-driven safety messages under consideration are transmitted.