The Weighted Function Based GPSR Protocol In Vanets

In recent years,with the rapid development of wireless communication network technologyand the growing number of car ownership,Vehicular Ad-hoc Networks(VANETs)as an important part of the Intelligent Transportation System(ITS)can provide more comfortable and safe driving experience for the driver.Due to the highly dynamic topology,the research of routing protocols is extremely important.Firstly,the weighted function based GPSR protocol in homogeneous situation are studied.We propose a weighted function WF(Weighted Function)of the next-hop candidate nodes to help vehicle selecting the next hop node within its communication radius.The weighted function considering the impact of link reliability,transmission delay and the direction of the next-hop candidate vehicle to achieve higher link reliability,less transmission delay.The sender vehicle will select the vehicle which has the largest WF value as the next-hop node to transmit information.Then we propose an improved GPSR routing protocol called WF-GPSR(Weighted Function based GPSR)based on the weighted function to solve the poor link quality problem caused by greedy forwarding in GPSR.We improve the conventional GPSR by changing the route discovery and route maintenance process to ensure both link reliability and transmission delay.Secondly,we study the weighted function based GPSR protocol in the heterogeneous situation.Due to the poor link quality problem of GPSR protocol and the problem that greedy forwarding couldn't minimize the hop number,we propose a hop number prediction method to improve the weighted function.Then we select the next-hop forwarding node based on the weighted function.Then we improve the GPSR protocol based on the novel weighted function which consider both link reliability and transmission delay to ensure the Qo S.Thirdly,we use the NS-2 simulator as the simulation platform to evaluate the performance of our proposed WF-GPSR protocol.We set up the simulation scenarios by Vanet Mobi Sim.Simulation results show that the performance including packet delivery ratio and average end-to-end delay of the proposed protocol is better in some situations.Meanwhile,WF-GPSR protocol performance more balance in terms of transmission delay and link stability compared toconventional GPSR protocol.