Abstract: Vehicular Ad-hoc Networks (VANETs) are the special class of Mobile Ad-hoc Networks (MANETs) with high mobility and frequent changes of topology. It is a type of highly dynamic wireless network that can be formed without the need for any pre-existing infrastructure which aims to improve the transportation system by integrating sensors, wireless networks, GPS, 2G and 3G technologies with the Ad-hoc networks. Due to higher mobility of nodes (vehicles), routing becomes the most challenging task in VANETs. A variety of research has been done on routing and several protocols have been proposed with their implementation. As VANET (Vehicular Ad-hoc Network) research field is growing very fast. It has to serve a wide range of applications under different scenarios (City, Highway). It has various challenges to adopt the protocols that can serve in different topology and scenario. The main objective of Vehicular Ad-hoc Networks is to build a robust network between mobile vehicles so that vehicles can talk to each other for the safety of human beings. This paper deals with the study of classification of different Ad Hoc routing protocols and their different routing techniques.
Keywords: VANET (Vehicular Ad-hoc Network), MANET (Mobile Ad-hoc Network), routing protocols, AODV, AOMDV.