Research On Motion-driven Packet Forwarding Method In UAV Networks

UAV(Unmanned Aerial Vehicle,UAV)network routing technology is often used to transmit messages collected by UAVs.At present,in many scenarios such as the classic secene-search,rescue,UAVs are controlled by the ground station.In order to determine the location of the target as soon as possible,UAVs need to search the image information of the area and transmit them back to the ground.In this scenario,UAV network needs to transmit information back to the ground station quickly and accurately in the form of multi hops.At this time,what kind of routing strategy is used for message transmission in UAV network is a crucial issue.This article focuses on the investigation search and rescue scenario,and studies the message transmission path and node heat balance respectively;On the one hand,how to optimize the UAV network routing strategy can reduce the back and forth transmission of messages;On the other hand,this article studies what kind of strategies can be used to improve the problem of poor network transmission performance caused by "heating" imbalance.The specific research contents are as follows:(1)In terms of message transmission path optimization,there are problems such as high message delay and a high proportion of "ping-pong effect" in view of sortcomings of existing methods in finding the optimal message transmission path.We proposes a method for optimizing the message transmission path of UAV networks--DPTM(a UAV Message Transmission Path Optimization Method under Dynamic Programming,DPTM).Considering UAVs' mission-driven nature in the search and rescue scenario,the position of drones can be determined in advance during the execution of the mission.By designing the UAV network,DPTM sets the equation of each drone's motion and position at any time in advance.And then DPTM considers all positions of all drones at each moment globally to get the most excellent object,so as to obtain the optimal path for messages to reach the destination node,which can reduce "ping-pong effect" ratio and delay.DPTM can get the optimal message transmission path during the normal task execution of the UAV under certain scenarios,and has better message transmission performance.Experimental results show that DPTM is superior to existing algorithms in terms of ping-pong effect ratio,delivery ratio,delay,and hop count.(2)In terms of the optimization of “heating” balance,since UAVs are limited in energy during flight,it is necessary to avoid as much energy consumption of a single drone as possible.In view of the problems of "heating" imbalance in existing methods,which caused individual drone's energy consume too fast to perform tasks,etc.,a heat balancing optimization method based on regional layer division named PB(a Loading Balance Method for UAVs in the Same Area Lays,PB)is proposed.Based on the idea of geographic routing,PB transmits messages to areas closer to the ground station,thus it changes the mode of message transmission from "point to point closer to the destination node" to "point to area closer to the destination node".PB tries to avoid too many messages transmitting to a certain drone,and avoid the problem of UAV networks' deterioration caused by the "hot spot".In addition,by analyzing the uniformity of the drone distribution in the detection-search and rescue scenario,the existing method of ferrys does not play its role as a relay.Therefore,this article resets the operating rules of ferrys to make them more suitable for the scenario.Experimental results show that PB is superior to the existing algorithms in terms of popularity ratio,delivery ratio,delay,hop count,and ping pong effect ratio.(3)The simulation is used to compare designed algorithms with mainstream algorithms,and the scene model is built according to the characteristics of search and rescue scene.At the same time,the trajectory of the UAV is designed according to the operation rules of UAVs.In the same scene and the same trajectory,the results of designed algorithms and existing mainstream algorithms are analyzed in the delivery rate,delay,pingpong effect ratio,hops and other indicators.The results show that the algorithms we designed can get higher delivery and lower delay than existing algorithms.At the same time,PB can effectively solve the problem of unbalanced heating of UAVs,improving the UAV operation efficiency and task execution time.