ABSTRACT

Routing is one of the most significant challenges in Vehicular ad hoc networks and is critical for the basic network operations. Nodes (vehicles) in a Vehicular ad hoc network are allowed to move in an uncontrolled manner. Such node mobility results in a highly dynamic network with rapid topological changes. Caching the routing information can significantly improve the efficiency of routing mechanism in a wireless ad hoc network by reducing the access latency and bandwidth usage. Our work presents an analysis of the effects of route cache for this caching in on-demand routing protocols in Vehicular ad hoc networks. Our analysis is based on the Dynamic Source Routing protocol (DSR), which operates entirely on-demand. Using detailed simulations of Vehicular ad hoc networks, we studied a caching algorithm that utilize cache size as a design choice, and simulated each cache primarily over different movement scenarios drawn from various mobility models. We also evaluated a set of mobility metrics that allow accurate characterization of the relative difficulty that a given movement scenario presents to a Vehicular ad hoc network routing protocol, and we analyze each mobility metric’s ability to predict the actual difficulty in terms of routing overhead and packet delivery ratio experienced by the routing protocol across the highway and city traffic scenarios in our study. Finally we have shown that caching the routing data is beneficial.