Research On Improvement Of Location-based Routing Protocol In Unmanned Aerial Vehicle AD Hoc Network

Unmanned Aerial Vehicle AD hoc network is characterized by free node movement,dynamic topology change,limited channel bandwidth and unequal node distribution.Therefore,well-designed routing protocol is the key to construct unmanned aerial vehicle AD hoc network.The rapid node movement in UAV AD hoc network results in drastic changes in network topology,which seriously affects network performance.On the one hand,traditional routing protocols based on topology cannot achieve good routing performance;on the other hand,with the development of positioning technology,UAV can easily obtain location information.The routing protocol based on geographic location information is widely used in UAV AD hoc network.This thesis focuses on the classical Greedy Perimeter Stateless Routing(GPSR)protocol.Aiming at the shortcomings of GPSR protocol and the application requirements of Unmanned Aerial Vehicle AD hoc network,A GPSR protocol(GPSR based on Link Lifetime,Distance and number of Neighbor Nodes,GPSR-LDN)is proposed,which comprehensively considers Link lifetime,Distance and number of Neighbor nodes.The main research contents are as follows:1.In view of the failure of neighbor list caused by high-speed node movement,a maintenance mechanism of neighbor list based on link lifetime is designed by introducing such factors as node movement speed and direction.The link lifetime between nodes is used to screen failed neighbor nodes and eliminate the failure information of neighbor list.At the same time,the ability to adapt to the variable topology is enhanced and the stability of routing is improved.2.To solve the problem that the optimal next-hop forwarding node cannot be selected due to the distance factor as the only routing criterion,a routing policy is designed based on the distance,link lifetime and number of neighbor nodes.According to the created void avoidance list,relevant neighbor nodes are screened out,and the node with the largest weight is selected as the next-hop forwarding node by using weights and formulas,which can make full use of network information and find a reliable,stable and effective path.3.In order to solve the problem of route redundancy and loop routing caused by routing void,a peripheral forwarding strategy is designed based on the left hand rule and right hand rule,and data packets are copied and forwarded by the left hand rule and right hand rule.In addition,creating a data transmission table can reduce the repeated forwarding of the same data group and improve transmission efficiency.In order to verify the feasibility and effectiveness of GPSR-LDN protocol,this paper conducted performance tests on NS3 simulation platform.Simulation under different node moving speed,node number and network load scenarios,the results show that the GPSR-LDN protocol proposed in this paper can effectively reduce the average end-to-end delay and average hop count of UAV AD hoc network,and improve packet delivery rate and network throughput,which proves the advantages of the designed GPSR-LDN protocol in performance.