Research On MAC Protocol Of UAV Cluster Ad Hoc Network

Unmanned Aerial Vehicle(UAV)systems are evolving towards clustering and intelligence.Communication network,as the basis for communication between UAVs,is the key to intelligent coordination of UAV cluster.UAV ad hoc network has the characteristics of flexible network construction and strong survivability,which is an important technology for building UAV networks.The characteristics of UAV and its application scenario put forward higher requirements on network latency and throughput performance.A reasonable MAC protocol allows network nodes to use communication resources efficiently,which helps upper-layer protocols such as the network layer and the transport layer to provide better service quality,and enables the network to better meet the communication needs of UAV clusters.This thesis takes the MAC protocol of UAV ad hoc network as the research starting point,including the following contents:1.The study of MAC protocol for UAV ad hoc network is mainly based on CSMA/CA and TDMA.TDMA protocol is more suitable for application in UAV ad hoc network that require lower latency and higher network load.It can meet the requirement of low latency for UAV ad hoc network control and cooperative services by allocating fix time slots to each UAV node and selecting the appropriate frame length,but there is a problem of wasted time slot resources.Using the wasted time slot resources in a competitive way can improve the utilization efficiency of time slot resources,but there is a possibility of slot use conflict,the effect of improvement is limited,and it is difficult to ignore the competitive cost when taking short frame length to ensure low latency.In order to solve the above problem,Idle Slot Reservation TDMA(ISR-TDMA),an improved TDMA protocol that uses wasted time slots in a reservation manner is given.Compared with the contention method,reservation method has less overhead and can use slot resources more efficiently.2.Multi-hop UAV network can expand the coverage distance of the UAV system.Routing protocol is the key to building a multi-hop network,and it is also one of the research focuses of the UAV ad hoc network.Most researches on routing protocols use CSMA/CA as the MAC protocol.CSMA/CA is a competing MAC protocol,using channels by a competition way is inevitably lead to conflicts in data transmission and affect network packet loss rate and throughput.TDMA protocol uses channels in an orderly manner,which is more conducive to achieving low packet loss and higher throughput.After briefly introducing the basic principles of the three basic routing protocols commonly used in UAV ad hoc network,OMNe T ++ is used to compare the performance of these routing protocols in TDMA network.3.ISR-TDMA has the problem of idle slot use conflict in a multi-hop scenario,which cannot effectively improve the efficiency of slot resource use.After analyzing the cause of the problem,by using a geographical location-based slot allocation and usage scheme to limits the way nodes use slots,the problem of slot conflict is effectively alleviated.