针对传统TDMA固定分配方案在节点间业务量动态变化时,存在着信道利用率较低的问题,设计了一种基于全局时隙转让的短波地空网动态TDMA协议(TDMAprotocolbasedonWholeTimeslotTransfer,WTT-TDMA),以可靠性较高的地面节点作为控制中心,实现时隙分配可控下的动态利用。提出了全局时隙转让算法(WholeTimeslotTransferalgorithm,WTT-ALG),地面节点根据时隙评估过程后生成的节点时隙请求数,按需协调全局空闲时隙的转让,重新分配节点业务时隙数。利用OPNET平台进行仿真建模,并与HFTP协议和TDMA协议作了对比分析。仿真结果表明,WTT-TDMA相比HFTP协议和TDMA协议,在消息投递率、平均时延和吞吐量方面具有更优异的性能。
A dynamic TDMA protocol based on Whole Timeslot Transfer(WTT-TDMA)is designed to solve the lower utilization ratio of channel when business is not fixed between nodes in the TDMA. Timeslot is utilized dynamically by the more reliable ground node as the control center. The Whole Timeslot Transfer algorithm(WTT-ALG)is proposed. The business timeslot number of nodes is assigned according to the request timeslot number of nodes which is generated by the timeslot estimation process. The performances comparison is made with HFTP protocol and TDMA protocol by OPNET. Simulation results show that WTT-TDMA protocol has better performance than HFTP protocol and TDMA protocol on the parameters of message delivery ratio, traffic delay and network throughput.