Microscopic Vehicle Mobility Model

Abstract

Unlike traditional mobile ad hoc networks, the high node mobility in VANETs can cause frequent network topology changes and fragmentations. As discussed in Sect. 1.3, any change in network topology is directly or indirectly related to the change in distance headways among vehicles. This chapter presents a novel microscopic mobility model to facilitate VANET analysis. Firstly, A discrete-time finite-state Markov chain with state dependent transition probabilities is proposed to model the distance headway. The model captures the time variations of a distance headway and its dependency on distance headway value. Secondly, highway vehicular traffic is simulated using microscopic vehicle traffic simulator, VISSIM. Vehicle trajectory data collected from highways in the U.S. and that simulated by VISSIM are used to demonstrate the validity of the proposed mobility model for three vehicle density ranges. Finally, the proposed mobility model is extended to a group mobility model that describes the time variations of a system of distance headways between two non-consecutive vehicles. Using lumpability theory, a Markov chain with reduced state-space is proposed to represent the mobility of a group of vehicles.