Research On Routing Algorithms Based On Vehicular Ad Hoc Network

As an essential part of intelligent transportation systems, Vehicular Ad hoc Network can be probably applied to provide services that include secure data transmission, traffic management, payment and location etc. by V2V/V2 I. VANET has some characteristics, such as vehicle nodes move at a rapid speed, network topology changes frequently and uneven distribution of nodes. As a result, links between vehicle nodes break down frequently and communication routes become unstable. Therefore, considering the characteristics of VANET and designing a suitable routing protocol for VANET has become the work of a great theoretical and practical significance. The major work in the thesis includes:1)Based on the topology routing protocols, a co-simulation platform is set up by the Vanet Mobi Sim2.0 and NS2. By importing reality street topology and nodes mobility model with lane changes and overtaking functions to improve the rationality of simulation scenarios. On the basis, routing performance of the AODV and VSRP(Stable Routing Protocol for VANET) protocol is comparatively studied under different number of vehicles and packet sending rate. Simulation results show that: the overall routing performance of VSRP protocol is better than conventional AODV, but it still not good enough to satisfy characteristics of VANET.2)On the basis of VSRP protocol, the thesis proposes a novel routing protocol called ESRP(Enhanced Stability Route Protocol for VANET) by introducing into Longest Routing Expiration Time mechanism and Multi-path Routes Backup mechanism. The ESRP selects a more stable route with longest routing expiration time for data transmission in the routing selection phase to limit the flooding broadcast of RREQ packets, improves routing stability and reduce routing overhead. In routing maintenance phase, multi-path routes backup mechanism is used to improve routing repairing efficiency and shorten routing recovery time.3)Comparative performance analysis of AODV, VSRP and ESRP protocol are done under the different number of vehicles and packets sending rate. Simulation results indicate that: Compared to VSRP and AODV protocol, ESRP protocol can increase the packet delivery ratio, reduce the average end to end delay and decrease the routing overhead. In summary, ESRP protocol is more suitable for VANET.