机载战术网多信道S-ALOHA协议设计与分析

针对机载战术网(airborne tactical network, ATN)高动态、大尺度、节点稀疏分布、通信业务多样等特征,以及高可靠、低时延的信息传输需求,提出一种新的多信道时隙ALOHA(multi-channel slotted-ALOHA, MC-S-ALOHA) 协议。该协议采用一种基于活跃节点数量的退避机制,其竞争窗口的大小随网络中活跃节点数量的变化而自适应动态调整。针对提出的协议,通过对网络中忙碌信道数量和活跃节点数量建立二维马尔可夫链模型、对节点发送缓冲区建立一维马尔可夫链模型,理论推导了网络吞吐量、分组端到端时延和分组成功传输概率的数学表达式。仿真结果验证了理论推导的准确性,并表明该协议能够有效满足ATN的性能需求。

Design and analysis of a multi-channel S-ALOHA protocol for airborne tactical networks

For the characteristics of high dynamic, large scale, sparse nodes distribution, diversity of communication traffic, etc., and the high reliability and low latency of information transmissions in airborne tactical networks, a multi-channel slotted-ALOHA (MC-S-ALOHA) protocol is proposed. The protocol adopts a backoff mechanism based on the number of active nodes, whose size of the contention window is adjusted adaptively and dynamically with the number of active nodes in the network. For the proposed protocol, by establishing the two-dimensional Markov chain model on the number of busy channels and active nodes, and the one-dimensional Markov chain model on the sending buffer of nodes, the mathematical expressions of network throughput, packet end-to-end delay and packet success probability are derived. The simulation results verify the accuracy of the theoretical derivation, and show that the protocol can meet the performance requirements of airborne tactical networks.