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《(most cited)An Efficient Multipolling Mechanism for IEEE 802.11 Wireless LANs》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、764IEEETRANSACTIONSONCOMPUTERS,VOL.52,NO.6,JUNE2003AnEfficientMultipollingMechanismforIEEE802.11WirelessLANsShou-ChihLo,GuanlingLee,andWen-TsuenChen,Fellow,IEEEAbstractÐToexpandsupportforapplicationswithQoSrequirementsinWirelessLocalAreaNetworks(WLANs),the802.11ETaskGroupwasformedtoenhanceth
2、ecurrentIEEE802.11MediumAccessControl(MAC)protocol.Themultipollingmechanismwasdiscussedinthetaskgroup,butsomeproblemsremainunsolved.Inthispaper,weshowanoveldesignofthemultipollingmechanismwiththeadvantagesofhighchannelutilizationandlowimplementationoverhead.Inourproposedmechanism,wirelesssta
3、tionsuseapriority-basedcontentionschemetocoordinateinthemselvesthetransmissionorderonthechannel.Moreover,weproposeapollingschedulemechanismforourproposedmultipolltoservereal-timetrafficwithconstantandvariablebitrates.Theboundeddelayrequirementofthereal-timetrafficcanbesatisfiedinourschedulin
4、gmodel.Weestablishanadmissiontesttoestimatethesystemcapacityandtodeterminewhetheranewconnectioncanbeaccepted.Westudytheperformanceofourproposedmechanismanalytically,aswellasthroughsimulatedexperiments.TheresultsshowthattheproposedmechanismismoreefficientthantheonediscussedintheIEEE802.11Etas
5、kgroup.IndexTermsÐMultipolling,pollingschedule,IEEE802.11,wirelessLAN,MediumAccessControl.æ1INTRODUCTIONWITHtheincreasinguseofportablecomputers,hand-Thecarriersensingcanbeperformedbothatthephysicalsets,andwirelessnetworks,atrendonprovidinglayerandattheMACsublayer.Prioritylevelsforaccesstowir
6、elessdataserviceshasemerged[13].ThewirelessthechannelareprovidedthroughtheuseofInterframecommunicationbandwidthhasbeenlargelyincreasedwithSpacessuchasSIFSandDIFS.Thebackoffprocedureisusedadvancesofchannelmodulationtechniques.Thetransmis-forcollisionavoidance,whereeachSTAwaitsforabackoffsiono
7、freal-timemultimediadatainthewirelessnetworkstime(arandomtimeintervalinunitsofslottimes)beforebecomesfeasible.Supportforreal-timeservices,particu-eachframetransmission.ThePCFprovidescontention-freelarlywithQualityofService(QoS)guarantees,isachallen
