TECHNOLOGY TRENDS AND ISSUES FOR PHY & MAC LAYER OF DSRC IN VANET

With the increase in number of vehicles on road the possibilities of potential threats and road accidents has been also increased. To prevent these situations all the vehicles should be equipped with the communicating on board unit so that the vehicles may communicate with each other and prevent the potential threats up to a certain level. Vehicular Area Networks are Ad-hoc networks in which all the vehicles communicate with each other without wires and share information which provides safety, entertainment as well as comfort applications. In this paper various MAC protocols IEEE802.11p, Ad-hoc MAC and directional MAC for VANET has been overviewed. This paper provide the idea to solve the hidden terminal and exposed node problem by using Ad-hoc MAC and to minimize the number of collisions and interference by using directional MAC.