Research For Broadcast Algorithm And Route Protocol Based On Probability In VANET

Nowadays, Vehicle has become a necessary for people, but also brought traffic congestion, traffic accidents and so on. Vehicular Ad Hoc Network (VANET) as the core part of intelligent transportation system, it has been researched by sectors and invested a lot of resources so that it can better alleviate traffic and reduce traffic accidents. This paper focuses on the broadcast algorithms and routing protocols in VANET.Firstly, as for safety messages in VANET, we propose a broadcast algorithm named PDBM based on probability and Waiting delay to reduce redundancy?competition and conflict. Taking consideration into geographic position as well as nodal load when calculate the probability of potential forward nodes, by constructing probability forwarding function to design adaptive and competitive delay timer for relaying nodes to achieve high reliability and validity. Using SUMO and NS2 co-simulate PDBM to show that the performances of package permeability,forwarding node proportion and transmission delay have been enhancedSecondly, to improve routing stability and to reduce link breakage, we proposed a new routing protocol named AODV-SL.by combining the relative speed of intervehicles, the forwarding angle and load to propose node stability (St), then using the accumulation of stability and number of hops to design the link quality and choose the two highest link quality as the optimal?sub-optimal path during the process of route setup; While detecting link breakage, using the way of optimal route and suboptimal route switching directly as well as local route repairing in homodromous neighbor nodes and reversed neighbor nodes. The simulation results indicated that AODV-SL have improved a lot at the aspect in end to end delay, packet delivery ratio and routing overhead compared to HLAR and AODV?...