Design And Verification Of A Uav Ad-hoc Network Protocol Based On Dynamic TDMA

UAV Ad-hoc network has a wide range of applications in the military and civilian fields due to its flexible networking and strong self-healing characteristics.Channel access technology controls the allocation of wireless resources and plays a key role in the performance of the UAV self-organizing network.Therefore,the UAV self-organizing network channel access technology has become a research hotspot.UAV Ad-hoc Network Channel Access Technology includes two types.One is the competition mechanism type,and the other is the TDMA type.When the network scale is large,the competing MAC protocols will increase the probability of transmission conflicts,making the network performance drop sharply,while the TDMA MAC protocols reduces the probability of transmission conflicts through time slot reservation,and has stable transmission performance.However,the TDMA protocols require time synchronization technology,and due to the complexity of the protocol itself,the difficulty of its implementation has also increased significantly.This paper designs a dynamic TDMA-based UAV self-organizing network protocol and its software and hardware implementation.The main work of the full text is as follows.Firstly,this paper analyzes the characteristics and main problems of the UAV Adhoc network,expounds the differences between the UAV Ad Hoc network and the traditional ad hoc network,and then investigates the existing wireless ad hoc network access technology.It made a classification,summarized the characteristics and applicable scenarios of various MAC protocols.According to the specific scenario requirements of UAV ad hoc network project,the project is analyzed from two aspects of function analysis and index analysis,and the influencing factors of network access delay and transmission delay are analyzed,which provides some practical guidance for protocol design.Secondly,combined with the project requirements of UAV ad hoc network,a dynamic TDMA MAC protocol scheme is designed based on P-TDMA algorithm.The scheme considers the service application amount of nodes and allocates more time slots for nodes with large service requirements.At the same time,a two hop network layer scheme and time synchronization algorithm are designed.On the basis of the protocol scheme,this paper presents the software design and implementation of embedded FreeRTOS real-time operating system,including the overall framework of the software and the implementation of key sub modules.Finally,the laboratory test environment of UAV ad hoc network system is built.The function verification of no center networking and the test of transmission performance is completed.The test results show that the synchronization error of the entire network is about 60 ns,and the transmission delay is as low as 15 ms in a 10-node network.By performance testing,the system can meet the requirements of low error time calibration,fast network access and multi-priority service transmission.To sum up,a complete design scheme of UAV ad hoc network system and the realization method of the software and hardware of the key modules are given,which has passed the experimental verification and has strong engineering practical value in the practical application of the swarm UAV network.