A hybrid clustering-based MAC Protocol for Vehicular Ad Hoc Networks

One of the challenges for Vehicular Ad hoc Networks is the safety messages could not be transmitted in a fast way. When exchanging messages between vehicles, there are some issues that must be addressed, including the high node mobility, unreliability of wireless channels and hidden terminal problem. A hybrid clustering-based MAC scheme for Vehicular Ad-hoc Networks is proposed to overcome the lack of mobility to support channel utilization and network stability. Cluster heads are elected based on their motility factors in order to improve the stability of clusters. The proposed MAC protocol leverages contention-free and contention-based MAC scheme to support the requirement of safety messages. The numerical results confirm the efficiency of the proposed protocols in terms of low collision probability and low transmission delay.