Geographical Topologies of Routing Protocols in Vehicular Ad hoc Networks – A Survey

--Vehicular Ad Hoc Networks (VANETs) have grown out of the need to support the growing number of wireless products that can now be used in vehicles. These products include remote keyless entry devices, personal digital assistants (PDAs), laptops and mobile telephones. As mobile wireless devices and networks become increasingly important, the demand for Vehicle-to-Vehicle (V2V) and Vehicle toRoadside (VRC) or Vehicle-to-Infrastructure (V2I) Communication will continue to grow. Vehicular Ad hoc Network (VANET), a subclass of mobile ad hoc networks (MANETs), is a promising approach for the intelligent transportation system (ITS). The design of routing protocols in VANETs is important and necessary issue for support the smart ITS. It is not effectively applied the existing routing protocols of MANETs into VANETs. In this paper, We introduce position based protocol in VANETs. It is observed that carry-and-forward is the new and key consideration for designing all routing protocols in VANETs. The temporary network fragmentation problem caused by rapidly changeable topology influence on the performance of data transmissions. The challenges and perspectives of routing protocols for VANETs are finally discussed in this article. Keywords—Geographical topology, VANET routing protocols, position based routing.