Research On Vehicle Routing Protocol Based On Link State Awareness In Urban Environment

With the rapid development of Intelligent Transport System(ITS),Vehicle Ad Hoc Network(VANET)is gradually becoming a hot research field.In some areas with high vehicle density in urban environments,frequent changes in network topology result in high communication load on nodes,leading to issues such as low data throughput,high communication overhead,high latency,and low delivery rate.It is urgent and important to design an efficient routing algorithm to overcome the challenges of high node load,high latency,and limited throughput in urban environments.The node mobility model in routing protocol simulation does not use real city scene maps,and a single "shortest hop" decision mechanism is used for routing selection,resulting in heavy communication load on some nodes and affecting the performance of the entire communication network.Introducing a mobile model based on real traffic scenarios and establishing bidirectional communication with it in vehicle mounted ad hoc networks,while changing the single routing decision mechanism,is highly promising.Firstly,this article couples the network simulator NS3 and traffic simulation model SUMO into the SMUVC(Simulation Model of Urban Vehicle Communication)model.By designing interface functions,online bidirectional communication between the two simulation platforms is achieved,providing a bidirectional coupling network simulation model for research on routing protocol standards.In terms of traffic simulation,the node trajectories in the real environment of SUMO are introduced and can be modified online in real time.Optimization and improvement are carried out to address the issues of fixed acceleration and fixed driver response time in the Krauss vehicle following model,and successfully transplanted.In terms of network simulation,the Wireless Access in Vehicle Environment(WAVE)protocol suitable for in vehicle environments has been introduced,providing an analytical basis for in vehicle security application simulation.The real-time online display of network simulation results can be achieved,and the network simulation results can change the node movement trajectory.Finally,protocol simulation tests were conducted based on the SMUVC model,and the experimental results met the requirements,verifying the reliability of network communication in the SMUVC model.Secondly,based on the SMUVC model,the LA-OLSR(Link Awareness Optimized Link State Routing)routing protocol is proposed to address the inability of existing VANET routing protocols to effectively combine multiple communication performance indicators of vehicle mounted ad hoc networks in urban environments,and to use a single "shortest hop" routing decision basis,resulting in network congestion and load imbalance.This protocol combines interface queue buffer capacity,number of bidirectional connections,and MPR of nodes＿Several communication indicators such as the number of S and the transformation rate of one hop neighbor nodes are comprehensively considered through the Analytic Hierarchy Process to select routes,and algorithms are designed to dynamically adjust the sending time interval of control messages to meet the communication performance requirements in high-density urban environments.The simulation results show that the LA-OLSR protocol improves data delivery rate and network throughput,reduces communication overhead,reduces latency,and achieves node communication load balancing.