The Research Of The VANET’s Routing Mechanism Based On Connecting Time

With the rapid development of economy and the speeding up of urbanization, thelife level of people is increasing day by day, the growth of the purchasing powerpromote the rapid development of auto industry. With the number of vehiclesincreasing fast, a series of problems appear, such as traffic congestion, frequent trafficaccidents, parking space tension.Intelligent transportation System, ITS (IntelligentTraffic System) is dedicated to the advanced science and technology application in thefield of traffic management, to solve the problems fundamentally. The VANET as thecore component of intelligent transportation systems, play an irreplaceable role onslowing down the traffic pressure and improving the driving safety. Get more andmore attention.The VANET belong to the Mobile Ad hoc networks, exchange traffic informationmainly depends on the two patterns, car to car and car to the infrastructure by the sideof the road. So the routing protocol is one of the key technology to solve. But due tothe instability of the wireless channel and the rapid speed of the vehicle node, thefracture of communication link often occurs, this makes high packet loss and delay inthe transmit process of the message. Especially the traffic density is sparse, theproblem performance more obvious.For the above problems, the paper proposes a road connectivity evaluationmethods, use the location, speed, direction and acceleration information to estimatethe maintain communication time between vehicles, then get the connecting time ofthe road. In addition this paper proposes a new road by the mechanism，Themechanism refers the connecting time, mark the connected state on the road topology.The application of the shortest path algorithm on the connecting roads effectivelyreduces the packet loss rate caused by frequent fracture of the link, especially in thedensity traffic time.In the article, use the simulation tool NS2to realize the routing protocol. Create the city path with MOVE and set related parameters of city vehicles run. Result showsthe protocol is superior to the traditional routing protocols GPSR and AODV inpacket loss rate, delay and network throughput, especially in traffic density issmall,more suitable for the network environment of the VANET.