第7卷第3期 智能系统学报 Vol.7 No.3 2012年6月 CAAI Transactions on Intelligent Systems Jun.2012 D0I:10.3969/i.issn.16734785.201110002 网络出版t地址：htp://www.cnki.net/kcma/detail/23.1538.TP.20120518.0839.001.html 一种能量有效的无线传感器网络轮询接入控制协议 何敏，赵东风，保利勇，左朝树 (1.云南大学信息学院，云南昆明650091：2.西南通信研究所保密通信重点实脸室，四川成都610041) 摘要：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PCP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P℃F-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P℃℉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. 关键词：无线传感器网络：PCF;能量有效；轮询服务；接入控制；轮询接入控制 中图分类号：TP393文献标志码：A文章编号：1673-4785(2012)03026506 An energy-efficiency polling access control protocol for wireless sensor networks HE Min',ZHAO Dongfeng',BAO Liyong',ZUO Chaoshu? (1.School of Information Science and Engineering,Yunnan University,Kunming 650091,China;2.Science and Technology on Com- munication Security Laboratory,Southwest Institute of Communication,Chengdu 610041,China) Abstract:Although the energy waste is well controlled on the medium access control (MAC)layer under the peri- odic sleeping point coordination function(PCF)scheme in wireless sensor networks(WSN),the system perform- ance declined and the system query energy cost increased because the node loads were ignored.Based on the limit- ed 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 perform- ances,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. Keywords:wireless sensor networks (WSN);point coordination function(PCF);energy efficiency;polling serv- ice;access control;polling access controll 无线传感器网络（wireless sensor networks, 医疗、建筑物监测、智能家居和安全报警、反恐和公 WSN)综合了传感器技术、嵌入式计算技术、分布式 共安全、商业等领域都有重要的科研价值和广阔的 信息处理技术和无线通信技术，在军事、环境监测、 应用前景.由于传感器节点通常依靠电池供电，能量 收稿日期：2011-10-11.网络出版日期：2012-05-18. 有限，不能直接应用在现有的无线通信协议中，通常 基金项目：国家自然科学基金资助项目(61072079)：云南省教育厅科 的解决办法是采用休眠机制，减少节点在空闲时期 学研究基金资助项目(09y0042). 通信作者：何敏.E-mail:heather_.hee@163.com. 的能耗.随机竞争接入能为突发性数据提供灵活的