Clustering and OFDMA-Based MAC Protocol (COMAC) for Vehicular Ad Hoc Networks
The IEEE community is working on the wireless access in vehicular environments as a main technology for vehicular ad hoc networks. The Medium Access Control (MAC) protocol of this system known as IEEE 802.11p is based on the Distributed Coordination Function (DCF) of the IEEE 802.11 and enhanced DCF of the IEEE 802.11e that have low performance especially in high-density networks with nodes of high mobility. In this paper, the authors propose a novel MAC protocol where nodes dynamically organize themselves into clusters. Cluster heads are elected based on their stability on the road with minimal overhead since all clustering information is embedded in control channel's safety messages.