Research And Designing Of Routing Protocol For Urban VANET

The vehicular ad hoc network(VANET) is a special form of mobile ad hocnetwork(MANET). The critical difference between a VANET and a MANET is thatVANET uses mobile vehicles as mobile nodes. VANET can provide communicationsbetween vehicles or between vehicle and road side unit with the help ofcommunication devices configured on vehicles. Compared with MANET, VANET hasmany special characters such as limited bandwidth, fast moving mobile nodes,quickly changed network topology, constraint of vehicle moving model, weakphysical security and other features. These special characters makes some of theclassical MANET routing protocols performs inefficiently or even unavailable inVANET. Therefore, in this paper we propose a routing protocol for urban VANETunder a large number of researches on VANET routing algorithms.In this paper, we begin with the research of main features of VANET andmulticast techniques used in routing protocols. Then, we propose a routing protocolfor urban VANET with multiple hotspots. Due to the large density of vehicles andgreat number of hotspots in urban circumstance, the essential problems to be resolvedduring the designing are minimizing the packet delivery delay and packet deliveryoverhead. So we introduce the Steiner tree to our routing protocol. First, a sub Steinerrouting tree is built for each hotspot. Then, a merged Steiner tree is built when seriousoverlapping happens. Our purpose is maximizing the overlapping and minimizingnetwork resource and delivery delay.Simulation results show that our routing protocol outperforms RTDF in thepacket delivery delay and packet delivery overhead when working in the urbanVANET circumstance.