Density-Based Threshold Algorithm In Vehicular Ad-Hoc Networks

An analytical model is first proposed in this paper to study the performance of the medium-access control (MAC) protocol for safety applications in vehicular ad-hoc networks (VANETs). Two access schemes for VANET safety applications including random access and cluster-based access are considered. In the proposed analytical model, packet delivery ratio (PDR) and transmission delay are considered as the two factors of robustness. Next, a density threshold algorithm is proposed to help choosing the favourable access scheme between random access and cluster-based access according to a metric derived by a combination of the two robustness factors. We also demonstrate a series of evaluation results which validate the proposed models well.