水下声音网络中基于簇的按需时间共享MAC协议

On Demand Time Sharing MAC Protocol Based on Cluster in Underwater Acoustic Networks

水下声音网络中基于调制解调器的商用系统具有传输率低、前同步码长两大特征,严重降低了媒介访问控制协议(MAC)的性能;针对上述问题,分析了调制解调器特征对当前水下声音网络两种主流MAC协议(随机访问MAC,握手MAC)的影响,提出了一种基于簇的按需时间共享MAC协议(COD-TS);该协议采用簇技术实现了局部调度和按需响应特性;文章首先给出单跳网络的COD-TS协议的含义,提出相应的吞吐量模型;然后,实现方案多跳场景的扩展,仿真结果表明,相比于已有的Slotted ALOHA和RTS/CTS等协议而言,本文方案的吞吐量更优。

Commercial systems based on modem in underwater acoustic networks have two critical characteristics, low transmission rates and long preambles. It drastically degrades the performance of existing MAC protocols in the real world. In order to resolve this problem, this paper analyzed the impact of the modem characteristics on the random access-based MAC and handshake-based MAC, which are two major types of MAC protocols for underwater acoustic networks. An On-Demand Time Sharing MAC （COD-TS） based on cluster was introduced and analyzed, which adopted cluster technique to enable local schedule and on-demand response feature. COD-TS protocol for one hop network was introduced at first, the corresponding throughput model was proposed. After that, the scheme was extended to multiscenarios. Simulation results show that the throughput of the proposed scheme is better compared with the existing Slotted ALOHA protocol and the RTS/CTS protocol.