The Research Of Vehicular Ad Hoc Network Protocol Based On Multi-QoS Constraints

VANET (Vehicular Ad Hoc Network) is the self configuring network where the nodes are vehicles. VANET has become an attractive research topic in wireless conmmunication. Special features of VANET, such as frequently-changing network topology and high mobility nodes, make the QoS (Quality of Service) tasks of vehicular ad hoc network applications extremely challenging. At present, the QoS routing protocol is mainly aimed at the traditional mobile ad hoc network.Therefore, it's very important to provide QoS guarantee for vehicular ad hoc network.Combined with the characteristics of highway scenario, this paper designs a new routing scheme called RQ-AODV (Reliable QoS Routing Protocol based on the classsic on-demand routing protocol AODV). RQ-AODV can find the reliable route satisfying the multi-QoS constraints to transmit datas between rhe source node and the destination node.Aiming at the problem of updating QoS state informaton with delay and the large routing overhead in current QoS routing protocol, this paper proposes a routing protocol based on QoS candidate node called QCNVRP (QoS Candidate Node Based VANET Routing Protocol). In VANET, vehicles can exchange the informations with each other by the periodic messages. If the QoS state informaton for the node can meet the rule of QoS candidate node, the node is regarded as QoS candidate node. The vehicle can select the QoS candidate node as the intermidate node to send message in VANET.The simulation results show that RQ-AODV protocol improves the packet delivery ratio and reduces the average end-to-end delay at the expense of the routing overhead compared with PBMQR and the performances of QCNVRP are better than Q-AODV in packet delivery drop, delay and routing overhead.