Simulation-Based Study of Common Issues in VANET Routing Protocols

Vehicular communications have been one of the hottest research topics for the last few years. Many routing protocols have been proposed for such kind of networks. Most of them try to exploit the information which may be available at the vehicle by the time that a routing decision must be made. In addition, some solutions are designed taking into account the particular, highly partitioned, network connectivity in vehicular settings. To do so, they embrace the store-carry- forward paradigm of delay-tolerant networks. Despite the great variety of approaches which have been proposed, we found that there is a set of issues which are common to many vehicular ad hoc routing protocols in the literature. In this paper, we perform a simulation-based analysis of five of those protocols, which are representative of the various categories of vehicular routing. We describe in detail every problem and show simulation results which support our reasonings. Moreover, solutions to solve every presented problem are outlined. The paper is concluded with some guidelines which may be helpful to prospective VANET routing protocol designers.