I. Introduction
VANET is an application of wireless communication derived from Mobile Ad Hoc Network (MANET) for wireless communication technology pointing toward improving road transportation efficiency and driving safety. Recently, VANET has emerged as one of the most revolutionary networking models [1] . In this network, each vehicle creates multi-hop communication links and seeks data about surroundings. It uses the same principles of MANET with hosts replaced with vehicles. Vehicles plying on road can establish network with other vehicles to interconnect and exchange various information with stations constructed along roads. VANET makes vehicles mobile routers, relaying data between vehicles. VANETs are infrastructure-less by nature like MANETs with limited bandwidth. The main objective of VANETs is to deliver services to the users on the road through various applications such as entertainment, collision avoidance, vehicle diagnostic, maintenance and information from other vehicles etc. [2] . VANET provides seamless communication between vehicles, and between vehicles and the network stations on the roadside. It is mainly applied for safety and comfort applications. The safety applications allow the mobile vehicles to broadcast information such as traffic congestion, road conditions, abrupt stops and accidents. The comfort applications allow vehicles to use web browsing, access emails and infotainment with audio and video streaming. By hops communications, VANET applications can be classified into two types. The first one is single-hop broadcasting which is done for information related to safety or beacon. The other one is multi-hop that provides network access, conversation, data sharing, etc. [3] . In this way, drivers can get instantaneous road information from some static stations or connect to a hotel for reserving a place and utilize the nearest internet base station for internet access.
Basic Diagram of VANET [4]