The Research On Reliable Routing Protocol In Vehicular Networks

Vehicular ad hoc network (VANET) is an important part of the intelligent transportation system(ITS). Researching of it has a very profound value for the situation of traffic and improving people’s travel. Nodes has the feature of high speed and sensitive to the change of environment in VANET. It makes the design of efficient and reliable routing protocol very difficult and challenging in urban scenarios. Obstacles in urban easily cause network partitioning and hidden terminal problem. When we design routing protocol, we must pay more attention to it.This paper studies the vanet broadcast protocol used in different urban scenes and analyze their strengths and weaknesses. For the complexity of road in urban scene and the connectivity problems in network caused by the spare node, we propose a new urban broadcast routing protocol called MBP(moderate broadcast protocol). We propose the following three schemes for non-connection network to improve the communication efficiency. First, at least one node is responsible for the store--carry--forward task to ensure packets forwarded multi-direction. Second, the node of allocating store-carry-forward task forwards packets more than once, that is preventing packets to be discarded once failed to forward at the first time. Third, there is a mechanism to prevent broadcast storms in intersection, which reduce the redundant packets in the network. By the above three points to ensure the reliability of the communication of non-connection region. It is a fully distributed and without the help of infrastructure protocol. It can adapt to connection network and also apply to non-connection network.This paper is based on the network simulation tool NS2 and node mobility model simulator VanetMobiSim to generate realistic movement trajectory of node motion. We compared the proposed protocol with the MFlood protocol under different node density. Evaluate they on the network reachability, receive distance, transmission cost and reception cost performance index. They are simulated in manhattan model and real urban scene. The simulation results show that our proposed protocol is stable and efficient.