Probablity Flow Model Based Route Optimization Method for VANET

VANET is a special kind of MANET, composed by an ultra-server and large quantity of vehicles. Operators can get profit by providing information and purchasing useful messages from the terminals in the net, terminals can also get reward by transmit messages as router. A rational planning of routes which can maximize the benefit on condition that maximizes the bandwidth for the operators seems meaningful. Owning to the existence of selfish nodes, the transmit reliability of nodes is uncertain, as a result, we take the reliability of routes into consideration and put forward the optimization problem to maximize the profit under the premise that maximizes network´s load above certain reliability. To solve this problem, we introduce the concept of reliability into network flow theory and propose the idea of probability flow network. To conquer minimum cost flow problem based on probability flow network, we present the concept of flow network PNP0 to convert it into particular minimum cost flow problem. What´s more, incremental maintenance algorithms are proposed to adapt to VANET´s real-time property. Simulation proves that this method works well and achieves the target with low congestion in the network.