Research On Media Access Control Protocol Of Hierarchical UAV Ad Hoc Network

In recent years,with the development of UAV technology,multi-UAV system has been widely used in public and civilian fields.Compared with single UAV system,a multi-UAV system can complete tasks more efficiently,having a broader application scenario.Therefore,the UAV ad hoc network applied to multi-UAV systems has become a hot research field of current research.At present,in order to cope with the complex task environment,the hierarchical ad hoc network structure of UAVs has gradually become the main mode.The UAV hierarchical network consists of multiple clusters.A high-level UAV and multiple lowlevel UAVs form a cluster.The high-level UAVs serve as the backbone nodes to support the entire network topology construction and the low-level UAVs are used as ordinary nodes for actual task execution.The current research on UAV networking mainly focuses on single-layer network structure,and the existing research results cannot be applied to the hierarchical network structure.Therefore,it is particularly urgent to research and design network protocols for UAV hierarchical ad hoc networks.The media access control protocol is a key position in the entire UAV ad hoc network protocol stack,which directly affects the performance of the entire network.This article focuses on the media access control technology,and according to the characteristics of the UAV hierarchical ad hoc network,a set of media access control protocol for the UAV hierarchical ad hoc network is designed.Specific work includes:First,this article takes the overall network architecture as the starting point to analyze the characteristics of high-level UAV networking and low-level UAV networking.By comparing directional antennas with omnidirectional antennas,it is concluded that directional antennas are more suitable for high-level UAV networking,while omnidirectional antennas are more suitable for low-level UAV networking.In addition,in view of the limited energy of low-level nodes,energy-saving mechanism should be introduced to extend the effective working time of network.Secondly,the paper designs overall UAV hierarchical ad hoc network access control protocol UMAC which consists of high-level protocol and low-level protocol.First,this paper designs and implements the High-Level Unmanned Aerial Vehicle Media Access Control(HLUAV-MAC).The design idea of HLUAV-MAC is to use directional antennas to increase single-hop transmission distance and reduce transmission interference to improve overall network communication performance and stability.The main contents include frame structure design,data structure design,neighbor discovery algorithm design,and time slot allocation algorithm design.Secondly,this paper designs and implements the low-level unmanned aerial vehicle media access control protocol(LLUAV-MAC).It is planned to introduce energy-saving mechanism to the protocol to improve the overall effective working time while ensuring networking performance.The main contents include frame structure design,data structure design and centralized time slot allocation algorithm design.Finally,based on the OPNET simulation platform,this paper conducts modeling and simulation experiments on the overall hierarchical media access control protocol UMAC.Contrast with the existing Static Time Division Multiple Access(S-TDMA)protocol and Directional Media Access Control(DMAC)protocol.Experimental results show that this protocol can reduce end-to-end delay,increase throughput and reduce packet loss rate.At the same time,for the proposed low-level UAV self-organizing network energy-saving mechanism,this paper verifies its effectiveness by constructing simulation scenarios of different network scales and business volumes.Experimental results show that this energy-saving mechanism can extend the lifetime of the entire network.