一种适用于节点功率非对称WSN的改进S-MAC协议

An improved S-MAC protocol for power asymmetric WSN network

针对节点功率非对称的无线传感器网络中的隐终端问题,提出在RTS/CTS机制基础上增加广播Bandwidth Reservation(BRES)消息的改进协议。在改进协议中,通信节点的邻居节点根据侦听到的CTS消息动态广播BRES消息,使得与通信节点连接非对称的高功率节点在接收到BRES消息后推迟自身发送任务,从而避免了隐终端问题。仿真结果表明:相比S-MAC协议,改进协议减少了低功率节点的数据冲突并降低了其到目的节点的端到端延迟,提高了低功率节点和网络的吞吐量。

The communications are interrupted by the hidden terminals in the traditional MAC protocols when the nodes＇ power is asymmetric in WSN networks. In order to solve this problem, an improved protocol was proposed by increasing the broadcasting bandwidth reservation （BRES） message based on RTS/CTS. In this improved protocol, the neighborhood nodes will broadcast bandwidth reservation message intelligently after overhearing CTS. After receiving BRES, the high power nodes will inhibit their own transmissions for the duration. So the improved protocol avoids the interruption of hidden terminals. Simulation result shows that compared with S-MAC protocol, the improved protocol reduces the data collisions of low power node, decreases its delay to destination node and increases the throughput.