Research And Implementation Of Vanet Routing

Vehicular Ad hoc Network(VANET)is a wireless communication network in which vehicles exchange information within a certain communication range.Due to the limited communication distance between vehicles,communication between vehicles usually requires some relay vehicles to assist forwarding data.So how to select the relay node between vehicles and find the best transmission path is the research content of the routing algorithm in VANET.A better routing algorithm can transmit data faster and more reliable,which ensure the traffic safety and improve the traffic efficiency.First of all,this paper introduces the most typical Greedy Perimeter Stateless Routing(GPSR)algorithm and its improved routing algorithm.Aiming to solve the problem of instability of the single link in existing routing algorithms,this paper considers the routing solution using multiple connections and gives the theoretical analysis of multiple connections.Then,this paper proposes a hybrid relay node selection strategy routing algorithm,referred to hybrid selection routing algorithm for short.This routing algorithm combines two kinds of criteria for selecting relay nodes:that is,in the neighbor nodes of the sender,select the first relay node which is closest to destination,and then select the second relay which has the best link status with the sender.The sender then respectively forwards the data packets to the relay nodes which are selected by two different criteria.In addition,in order to further improve the performance of the hybrid selection routing algorithm,the pretreatment,location prediction,removal of duplicate data packets and other processes are included.Finally,we implement a hybrid routing algorithm by using NS-3 simulation tools.In the different scenarios of fixed node number and fixed node speed,we compared the hybrid selection routing algorithm's simulation results with other routing algorithms' and found that the hybrid selection routing algorithm can effectively improve the successful rate of data packet transmission.And when the node moving speed is fast,it can bring the lowest end-to-end delay.