Research On High Dynamic Stable Routing Protocol Based On AODV

With the recent development of IoT technology,mobile Ad Hoc networks(MANET)are widely used in military,medical,transportation and some other areas due to its advantanges of centerless,self-organizing features.Vehicle Ad Hoc Network(VANET)as an important part of the transportation system's modernization and Informatization has received more and more attention.The study of VANET was originally designed to improve the safety of travel and the efficient use of real-time traffic information.However,with the emerging of the Internet of everything in 5G,VANET has been given a new functional role,as a natural extension of the mobile network in the road travel scinario.As the VANET application environment changes,the VANET protocol in each layer can vary greatly.On-demand post-routing routing protocol is widely used in the routing layer.In VANET,the core problem of information exchange between nodes to be addressed in the network is the routing protocol.The current application of AODV routing protocol can be better adapted to the vehicle network compared to the DSR,DSDV and other routing protocols.However,the traditional AODV protocol can not meet the QoS requirements of the low latency service of the vehicle network due to its insufficent consideration of topology changing.In this thesis,we consider the problem of VANET network delay and frequent network topology changing.First,we study the metric of network dynamics--"neighborhood node changing rate",which can provide reference for the selection of subsequent simulation boundary conditions.On this basis,combined with AODV protocol source code we studied the protocol workflow and the reason why AODV protocol is "insensitive" to network topology change is analyzed.In the aspect of routing discovery,a stable path selection algorithm based on node moving speed is applied by modifying the routing request and route reply message format of AODV protocol,which has improved the life-time of the routing link to reduce the overall network delay and routing overhead.In the aspect of route maintenance,this thesis studies the local repair and source repair strategy,and revises the "HELLO broadcast mechanism" of AODV routing protocol.A fast route repair strategy based on two-hop neighborhood node information is proposed.Based on these revision,the improved routing protocol RAODV is proposed.In this thesis,the RAODV protocol is simulated in different simulation scenarios by NS2 simulation software.The performance of the new protocol is analyzed by the simulation results and compared with that of the AODV protocol.The results show that the RAODV can establish a more stable route link and after the failure of the route RAODV can complete the route repairing more quickly,reducing the overall network delay.