Shilpi Dhankhar 1, Shilpy Agrawal
In past few years, VANET (Vehicular Ad-hoc Network) has become a remarkable area for research analysis and development. VANET is a subgroup of MANET (Mobile Ad-hoc Network). VANET and MANET both are wireless networks which are characterized as self-configured and autonomous ad-hoc networks. VANETs differ from MANETs in terms of dynamic topology and high mobility. Due to unstable connectivity, high mobility and network partitioning, information routing in VANETs becomes difficult and challenging, thus creating a need for efficient VANET routing protocols. This paper provides a summary on VANET and gives its routing protocols which focuses on vehicle to vehicle i.e. V2V communication. This paper aims at classifying protocols on the basis of routing information and comparing them using following parameters namely methodology used, benefits/strengths and limitations. The paper compares reactive and proactive routing protocols based on their advantages and disadvantages, also discussing the challenges and research related issues for the routing mechanisms that exist in VANETs