一种能量有效的无线传感器网络轮询接入控制协议

周期性休眠的PCF机制虽然较好地解决了无线传感器网络的能耗问题,但没有考虑节点的负载状态,降低了系统性能,也增加了系统的查询能耗.以限定(K=1)服务为基础,提出了一种改进的PCF轮询控制协议,即具有混合服务策略的无线传感器网络轮询接入控制协议PCF-SS.该协议在保障公平性的前提下,能够根据节点状态动态调整优先级并改变服务K值,中心服务器AP则根据各节点的服务K值在每轮服务时对节点的下一轮服务时间进行预估计,并采用统一的服务时间表唤醒节点,达到节能的效果.仿真实验表明系统的平均等待时间、平均排队队长等性能指标比周期性休眠的PCF机制要好,能量的有效利用率更高,具有更长的生命周期,适合作为无线传感器网络的MAC控制协议.

An energy-efficiency polling access control protocol for wireless sensor networks

Although the energy waste is well controlled on the medium access control(MAC) layer under the periodic sleeping point coordination function(PCF) scheme in wireless sensor networks(WSN),the system performance declined and the system query energy cost increased because the node loads were ignored.Based on the limited service(K=1),an improved PCF polling control protocol,which is known as the point coordination function by the site status(PCF-SS) for WSN,was proposed.The priority of a node was variable by its status and the service K was correspondingly changed using this protocol.Therefore,the service time of the next turn could be assigned dynamically according to its status when the AP server came to service a node.Also,the nodes were awakened by a uniform service time table which was used to save their power.The experimental results indicate that the performances,such as the mean value of queue length and message waiting time,are better than when using the periodic sleeping PCF scheme.The energy usage is more efficient and the lifecycle is longer,making it suitable for the MAC protocol of WSN.