© 2014, IJARCSMS All Rights Reserved 278 | P age ISSN: 2321-7782 (Online) Volume 2, Issue 10, October 2014 International Journal of Advance Research in Computer Science and Management Studies Research Article / Survey Paper / Case Study Available online at: www.ijarcsms.com A Review on Vehicle-To-Vehicle Communication Protocols For Traffic Safety Using Co-Operative Collision Warning C. Gomathi 1 M.Sc., M.Phil., Assistant Professor, Dept. of CA and SS, Sri Krishna Arts and Science College, Coimbatore, Tamil Nadu – India D.Gandhimathi 2 MCA., M.Phil., Assistant Professor, Dept. of CA and SS, Sri Krishna Arts and Science College, Coimbatore, Tamil Nadu – India K. Devika Rani Dhivya 3 M.Sc., M.Phil., MBA., Assistant Professor, Dept. of CA and SS, Sri Krishna Arts and Science College, Coimbatore, Tamil Nadu – India Abstract: Vehicular ad hoc network (VANET), a part of mobile ad hoc networks (MANETs), is a capable method for smart transportation organisation. It has no fixed setup and instead relies on the vehicles themselves to deliver network functionality. Still, due to mobility constraints, driver performance, and high mobility, VANETs rally on characteristics that are melodramatically different from many nonspecific MANETs. In VANET communication can be classified into two ways (i) vehicle-to-vehicle (ii) vehicle-to-roadside unit. This paper gives a review on various communication protocols used in VANET to achieve low latency in delivering warning messages. A Vehicle-to-Vehicle communication protocol for cooperative collision threatening encompasses of mobbing control policies, service differentiation mechanisms and approaches for emergency warning dissemination. An overview provides the concept of Cooperative Collision Avoidance (CCA), Medium Access Control (MAC) and the routing layer and in Joint vehicle-vehicle/vehicle-roadside communication protocol emergency warning messages are simultaneously transmitted through Vehicle-to-Vehicle (V2V) and Vehicle-to- Roadside (V2R) communications in order to achieve multipath diversity routing. In addition, to improve further communication reliability and achieve low latency, a Multi-Channel (MC) technique based on two non-overlapping channels for Vehicle-Vehicle (V2V) and V2R (or R2V) have been proposed. Keywords: Cooperative collision, collision avoidance, communication protocols, vehicle-to-vehicle, vehicle-to-roadside. I. INTRODUCTION Equipment which uses moving cars as nodes in a network to create a mobile network is called as a Vehicular Ad-Hoc Network. VANET turns every contributing car into a wireless router, letting cars roughly 100 to 300 meters with one another to connect the nodes and, this produce a network with anextensive range. Whenever cars drop out of the signal range and the network, other cars can join in, linking vehicles to one another so that a mobile Internet is created. It is estimated that the first system that will blend this technology are police and fire vehicles to communicate with each other for safety commitments. Recent studies shows that about 60% of roadway accidents could be avoided if the driver was warned just one-half second before the collision occurs. There are different kinds of systems to assist drivers in the roads. Inter-Vehicle Communication (IVC) has attracted research attention from the transport industry of Japan, Europe and US. Traffic accidents have been taking thousands of lives each year, outnumbering any deadly diseases or natural disasters. Human drivers suffer from perception limitations on roadway emergency events, resulting in large delay in propagating emergency warnings, as the following