The Research Of Relay Node Selection Problem Based On Particle Swarm Optimization

Traffic safety is a enduring hot topic, vehicle ad hoc network (VANET) as the product which appeared with the development of wireless network technology can provide communications traffic, cooperative driving, and the hazard warning light traffic information release also has drawn more and more attention, and has become a hot research field gradually.The Basics of VANET is the vehicular wireless apparatus and corresponding wireless network protocol, with which real-time communication can been achieved either between vehicles and roadside infrastructure or inter-vehicle.But the practical application are subject to many limitations,such as the vehicle communication environment in the road,buildings and trees which will have an adverse impact on communication quality, thereby affecting the life-span of the network. Firstly the basic concept and the development of VANET are introduced in the paper. Then, the Minimization of the number of auxiliary nodes needed on the condition of ensuring network connectivity is analysed,on this basis, optimization model of the location of auxiliary nodes is established further to achieve the maximization the network life-span. Since it is a problem of NP,the nonlinear particle swarm optimization algorithm is adopted for solving in this paper. Finally, in order to AODV and DSDV for example,simulating the network life-span,the average delivery ratio and average latency under different conditions in the city environment before and after the optimization of auxiliary nodes. Simulation is carried out for the results of this study at the end of this thesis, and the effectiveness is verified also.In the intelligent transportation system, there will be more broad application prospects for the VANET in the future,which can make public traffic more safety and efficient.The research of this paper will be a reference to the practical application of VANET.