半双工水声通信网络吞吐量性能研究

Throughput Performance of Half-Duplex Underwater Acoustic Communication Network

水声通信是水下组网的物理层媒介,水声信道中传播时延大、带宽窄和节点能量有限等特点是影响水声通信网络性能的主要因素。本文基于时分多址技术,研究如何利用水声信道的大传输时延提高水声通信网络的吞吐量性能。基于半双工通信模式的假设,本文理论推导出具有非零传播时延的水声通信网络吞吐量上限值,并分析网络规模、通信负载、通信模式对网络吞吐量性能的影响。理论分析及仿真试验证明水声通信网络在单播通信及均衡负载情况下的吞吐量上限为紧上限;多播通信模式下网络吞吐量随着期望目的地址数的增加而无限趋近于网络节点数N;网络节点间的通信负载越均衡,网络的吞吐量性能越好。

Underwater acoustic communication is the physical medium of underwater network. Long propagation delays, limited bandwidth and limited energy of underwater nodes are the main factors which affects the performance of underwater acoustic communication network. In this paper, the possibility is fully explored that using long propagation delays to improve the throughput of underwater acoustic communication network on the basic of time division multiple access technique. Under the assumptions of the protocol model which has a single collision domain in a half-duplex unicast network, the upper bound of throughput is showed for an N-node underwater acoustic network with non-negligible propagation delay when the traffic load of nodes is unbalanced. The influence of network size, traffic load and communication mode on the performance of network throughput are analyzed. Theoretical analysis and simulation experiments show that the throughput of underwater acoustic communication is a tight upper bound in the case of unicast communication and balanced nodes. In multicast communication mode, throughput of the network is close to the network node number N with the increase of the expected destination number. The more balanced are the traffic load of nodes, the better is the performance of networks.