Vehicular adhoc network routing protocols in realistic situations

A vehicular ad hoc network (VANET) is an autonomous system of vehicle nodes are connected by wireless links. The routers are free to move randomly and organize themselves arbitrarily; thus, the network´s wireless topology may change rapidly and unpredictably. Such a network may operate in a standalone fashion, or may be connected to the Internet. Multi hop, mobility, large network size combined with device heterogeneity, bandwidth and battery power constrain make the design of adequate routing protocols a major challenge. In recent years, many routing protocols have been proposed for Vanet. Basically these protocols can be fit in one of two major categories: on-demand such as AODV, and proactive such as OLSR. A more comprehensive survey did early. In this survey, we will not focus on individual routing protocols; instead we will discuss some new ideas proposed recently mainly to improve Vanet throughput and scalability in different ways with some new routing metrics.