Research On MAC Protocol Of Tactical Waveform Based On Directional Antenna

In recent years,tactical internet developed rapidly in military informatization.Tactical waveform is a software defined radio communication system.It is responsible for data transmission and distribution of formatting information in the digital battlefield.It can realize the integration and reliable transmission of data,voice or video in complex battlefield environment.In tactical internet,it could improve the performance of network by optimizing the medium access control protocol(MAC).Therefore,researching on MAC has theoretical and practical significance.Based on the idea of directional antenna space division multiple access,we put forward the directional medium access control protocol(DMAC),then study the system structure,protocol framework,running logic and dynamic resource management of directional media access control protocol and optimize neighbor discovery algorithm,dynamic slot allocation algorithm,link management and queues management.The main researched production of this dissertation includes the following aspects:(1)Designed the framework of DMAC and the proposal of dual channels,which include omni-directional channel and directional channel.It mainly solved a problem of high time complexity and designed the frame structure of DMAC including the structure of omni-directional channel and directional channel.Omni-directional channel contained the neighbor discovery sub-frame and broadcast sub-frame;while directional channel contained the build link sub-frame and data sub-frames.(2)Improved the neighbor discovery algorithm.Neighbor discovery algorithm is the foundation of building tactical internet.The unifying distributed slot assignment protocol is not suitable in tactical internet based on directional antenna.It takes too much time for neighbor discovery.Moreover,the logic neighbors may be different from the real neighbors.(3)Optimized the distributed slot allocation algorithm.It improved the resource utilization of wireless channel obviously.Slot will be reused just single hop away.In addition,this dissertation designed the packet format and solved the problem of resource conflicts.Finally,we make the scenario,node,process and antenna models of DMAC with OPNET in order to evaluate TDMA,USAP and DMAC,and we mainly analyze their time delay,throughput,slot reuse rate and packet loss rate.The results show that the performance of DM AC has improved obviously.