Performance evaluation of neighbor-awareness at the Media Access Control (MAC) layer for Vehicular Ad-Hoc Networks (VANETs)

Efficient medium access in Vehicular Ad-hoc NETworks (VANETs) remains a significant challenge. Two types of Media Access Control (MAC) approaches have been proposed, namely contention-based and contention-free. We propose a novel MAC approach called Discretized RAndom Medium Access (DRAMA) for VANET. DRAMA is based on a contention-free MAC, but unlike existing contention-free approaches, it is neighbor-agnostic. We evaluate the effect on performance of taking away all forms of channel coordination, thereby essentially removing neighbor awareness from an existing MAC approach. The evaluation is performed in terms of packet delivery ratio, receiver throughput, and end-to-end latency. We also present a performance evaluation of DRAMA and compare it to the IEEE 802.11p standard for various traffic scenarios. The results show that removing awareness from a MAC has a similar effect on performance to reducing awareness, in terms of number of hops used. Our performance results demonstrate performance improvements of 48%, 130%, and 73% over IEEE 802.11p in terms of packet delivery ratio, receiver throughput, and end-to-end latency, respectively.