Impact of node mobility on single-hop cluster overlap in vehicular ad hoc networks

Abstract

Node clustering is a potential approach to improve the scalability of networking protocols in vehicular ad hoc networks (VANETs). High relative vehicle mobility and frequent topology changes inflict new challenges on maintaining stable clusters. As a result, cluster stability is a crucial measure of the efficiency of clustering algorithms for VANETs. This paper presents stochastic analysis of the vehicle mobility impact on single-hop cluster stability in terms of the overlapping state between neighboring clusters. A stochastic mobility model is adopted to capture the time variations of inter-vehicle distances (distance headways). Firstly, we propose a discrete-time lumped Markov chain to model the time variation of the distance between two neighboring cluster heads. Secondly, first passage time analysis is used to derive probability distributions of the time to the first change in cluster-overlapping state and the inter-cluster overlapping time as measures of cluster stability. Finally, numerical results are presented to evaluate the proposed model, which demonstrate a close agreement between analytical and simulation results.