The Research Of Vanet’s Cluster Routing Mechanism

As the fast development of communication computer and sensor, Vehicular Ad Hoc NetWork(VANET) is changing the way of people know the world. VANET is extensively applied on Car pre-warning and Intelligent Traffic System and other fields. The VANET can build between V2V(Vehicular to Vehicular) and V2I(Vehicular to Infrastructure) intelligent information service system for sharing road real-time message by using the electronic device. So VANET can help to solve the problem of traffic jam and traffic safe. Because the VANET’s feature of high-mobility and channel-unstability, the VANET’s routing mechanism is one of the hot study subjects.This thesis first introduces the VANET’s current research and background, including VANET’s features applications and technical difficulties. Then it summarizes the VANET’s routing algorithm’s classification and VANET’s classical cluster protocol. Based on the lane-based-cluster(LBC) routing algorithm, this thesis quantifies the traffic flow and proposes traffic flow based VANET’s multi-weight cluster(TFC) algorithm. On electing the cluster head, the TFC algorithm considers traffic flow, car speed and position. That makes the cluster more stable when crossing the intersection. So TFC algorithm is suitable for the urban road. At the stage of cluster maintenance, this thesis considers the speed difference between the normal vehicular and the cluster head. If the speed difference is too big, it can influence the cluster stability. And considering the cluster maintenance packet loss, it is added one state of temporary node and it can reduce the cluster maintenance cost. At the stage of routing algorithm based on the cluster, this thesis uses AODV for reference adds the backup routing algorithm and proposes the TFC-IAODV routing algorithm. When the main routing path is invalid, it will be used the backup routing path. So it can increase the packet delivery ratio and reduce the end to end delay.This thesis uses SUMO(Simulation Of Urban Mobility) software build the urban road scenario and uses NS3 to simulate the TFC and TFC-IAODV algorithm compared with existing algorithms. The result shows that the TFC is more stable and TFC-IAODV has lower end to end delay and higher packet delivery ratio.