The Research Of Routing Protocol Based On Vehicle Traffic Density In VANET

With the development of intelligent transportation systems, vehicle mobile ad-hoc network has become a great valuable research field in Ad hoc multi-hop network.Routing protocol is the most important part of many key technologies in VANET,which largely determines the overall performance of the vehicle network. Due to thehighly dynamic change of topology in the VANET, the routing data transmission facesa large challenge. More and more attention from industry and academia is paid toVANET routing protocol, so research of VANET routing protocols become the currenthot spots direction.In the VANET of high-speed movement of nodes, road traffic condition greatlyaffected the performance of data transmission in the network. Location based routingprotocol is currently the most widely used routing protocol that can quickly discoverand create a routing link, with high real-time performance and reliability, especiallyfor high-speed mobile vehicle network. But GPSR protocol and its improved protocolstill exists some problems, such as local optimum, multi-hop redundancy, trafficsparse and poor reliability link. This paper made an improvement and optimization onthe shortage of GPSR (Greedy Perimeter Stateless Routing) routing protocol and therelated preliminary study. It proposed and designed the based on traffic densitynetwork protocol RPBTD, which can raised effective solution to these problems. Themain work is as follows:(1)Firstly, it analyzed and studied the VANET routing protocol and focused onanalyzing the burning questions of the automotive network routing protocol based ongeographical location GPSR and its existing improvements protocol.（2）It adopted for the method of classifying the nodes and made a prediction byprediction nodes whether should go through the intersection node.（3）It considered the effect of traffic density on routing performance, whichproposed and designed new traffic density calculation method and route transportmechanism. Without significantly increasing network bandwidth overhead of thepremise, the new protocol can effectively avoid local optimum phenomenon due tothe uneven distribution of traffic flow density.（4）While using the vehicle position, direction, speed and other information topredict the maximum communication time between vehicles. It can solve the problemof unreliable location information and the retransmission of packet loss which causedby neighbor table not updating in a timely manner. It can ensure the reliability of thelink.Finally, under different traffic density (different node density), it used NS2network simulation platform to do a simulation experiment between RPBTD protocoland the existing routing protocol GPSR and GPCR. Simulation results show that,RPBTD routing protocol compared to other vehicle routing protocol has beensignificantly improved in terms of latency and packet forwarding rate. It has superior performance and is ideal for the city scene.