A Survey on Routing Protocols in Vehicular Ad hoc Networks

The fast development of wireless communication technologies allows to enhance intelligent transport systems and utilizes these technologies in communications between vehicles in order to achieve road safety and others benefits to drivers. Recent studies focus on a new aspect of ITS (Intelligent Transport System) that is VANET (Vehicular Ad-hoc Network). This paper gives an overview of vehicular ad-hoc networks (VANETs) and the existing VANET routing protocols. VANETs are a group of moving vehicles with wireless communication. Every vehicle is a node in the network that plays the role of sender, receiver, and router to exchange data such as warnings, traffic conditions with other vehicles. Because of the high mobility of nodes in VANETs, the routing of data is the most challenging task in VANETs which have a dynamic topology. There are various types of routing protocols in VANET which are required by the ITS. Thus, we need to do a detailed research on various routing protocols and their strengths/weakness. The routing protocols basically focus on terms of delay, packet delivery ratio, bandwidth utilization and many other factors. However, there are challenges faced by the choose a proper routing protocol due to a dynamic topology and characteristics of VANETs. VANET is very advantageous as it helps in improving the road safety through reducing the number of accidents by warning drivers about the danger before they actually face it and other facilities to comfort drivers. Researchers have started working to overcome the challenges of data exchange between vehicles to minimize its constraints and maximize its multiple objectives.