无线传感器网络S-MAC协议的时延控制

Latency control in S-MAC for WSN

S-MAC协议是基于竞争的传感器网络MAC层协议,通过使节点空闲时自动转换为休眠状态来节省能耗。然而,休眠模式的引入导致了数据前传中断问题,使时延显著增加。时延问题使得S-MAC协议不能理想地应用于实时数据采集系统中。在S-MAC中引入了快速数据前传算法(FDF),仿真表明,采用FDF算法的S-MAC协议比采用自适应侦听算法的S-MAC协议显著减少了时延(对于10跳的网络,端到端的时延减少了将近一倍),因而显著地增加了网络的吞吐量。

S - MAC protocol is probably the most well - known contention - based sensor MAC scheme for the energy efficiency. It has exploited scheduled sleep/wake up cycles to conserve the energy. However, strict schedules incur a latency penalty in a multi - hop network when packets must wait for the next schedule for transmission. To reduce latency in multi - hop paths the fast data forwarding algorithm（FDF） are developed. FDF provides fast data forwarding paths by adding additional wake - up periods on the nodes along paths from sources to sinks. Through the simulation in NS - 2, compared with S - MAC based on the adaptive listening, the improved systems achieve much better performance in the throughput and latency.