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ID:34731738
大小:2.47 MB
页数:50页
时间:2019-03-10
《无线传感器网络高效mac协议的研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、摘要摘要无线传感器网络由于具有广阔的应用前景而在近几年受到学术界和工业界的广泛关注,是21世纪最重要的技术之一。介质访问控制(MAC)是无线传感器网络协议栈的重要组成部分,负责在传感器节点间分配有限的无线通信资源,协调网络中各节点的传输,构成传感器网络系统的底层基础结构。目前无线传感器网络中的MAC协议主要分为发送端启动的MAC协议和接收端启动的MAC协议两类。发送端启动的MAC协议主要利用时钟同步或前导传输建立发送端和接收端的连接,前者同步代价过高,后者网络利用率较低。接收端启动的MAC协议(RI-MAC)通过接收端主动与发送端建立连接,克服了发
2、送端启动算法的弊端,但又产生了发送端盲等的问题,导致数据传输延迟和发送端能耗增大。本文在仔细研究已有MAC协议的基础上,结合发送端启动的MAC协议和接收端启动的MAC协议的优点,提出了一种可自适应变换数据传输模式的MAC协议(IL-MAC)。该协议通过局部同步算法减少了发送端与接收端在建立连接时的盲等;根据节点的消息队列长度和数据的紧急程度决定当前使用发送端启动传输模式还是接收端启动传输模式,有效地解决了以上两类协议的问题。本文在网络仿真平台NS2上实现了IL-MAC协议,并在集中式拓扑、网状拓扑和随机拓扑三种网络结构下比较了IL-MAC和RI-M
3、AC的性能。仿真结果表明,IL-MAC在中低负载的条件下较有优势,而在高负载下明显好于RI-MAC。关键词:无线传感器网络,MAC协议,自适应传输模式变换I摘要ABSTRACTWirelesssensornetworks(WSN)havebroadapplicationsandsignificantvalue,andhavearousedtheindustryandacademicattention,itisoneofthemostimportanttechnologiesin21century.MediumAccessControl(MAC)pr
4、otocol,whichisapartofdatalinklayerinwirelesssensornetworksystem.Itsprimaryresponsibilityistoallocatethelimitedresourcesinwirelessnetworks,establishreliablecommunicationlinksbetweennodes,anditisusedtobuildthesensornetworksystemsinfrastructure.MACprotocolincurrentresearchisdivid
5、edintotwocategories,thesender-initiatedandthereceiver-initiated.Thesender-initiatedprotocolusingsynchronizationorthepreambletoestablishtheirconnection,hasproblemsarethatthecostofusingthesynchronizationistoohigh,andthelargenumberoflongpreamblesgreatlyreducesthenetworkutilizatio
6、n.Thereceiver-initiatedprotocol(RI-MAC)usethemessageperiodicallysendbythereceivertoestablishaconnectionwiththesender,itcansolvetheproblemsofthesender-initiatedprotocol,butintheRI-MACprotocol,thewaitingtimeofthesenderisgreatlyincreased,andthenitdelaysthetransferandincreasesthee
7、nergy-consumingofthesender.ThisthesisbasedonthecurrentresearchoftheMACprotocol,madefulluseofthebenefitsofthesender-initiatedandthereceiver-initiatedprotocol,proposeanewdutycycleMACprotocol,calledInitiator-convertibleandLocallysynchronizedMACProtocol(IL-MAC).Thisprotocolreduced
8、thewaitingtimeofthesenderandreceivertoestablishaconnection;By
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