Abstract
Vehicular ad hoc network (VANET) is a communication paradigm where vehicles can communicate directly with other vehicles or via intermediate fixed architectures called as road side units (RSU). Generally, the density of vehicles vary from very dense to shallow depending on various factors and different scenarios of the roads. In cities the number of cars is high and on highways and specifically in rural areas the density of vehicles varies. Therefore, direct vehicle to vehicle communication faces many problems in communication due to outages. In such scenarios the intermediate infrastructure needs to play an important role. Various routing protocols are implemented for VANETs with variety of design goals. In this paper we investigate the performance of proactive and reactive routing protocols, namely destination sequence distance vector (DSDV) and ad-hoc on demand distance vector (AODV) routing protocol, for various placement strategies of RSU based relays and in city scenario. The simulations were carried on NS2 which suggest that in various settings AODV perform better than DSDV routing protocol.