文档介绍：,,,-(DCF)(PCF)ess(CSMA)UseRTS/CTStoreservethechannel34Introduction–1istransmitting3willblockitstransmissionto4Whatifpowerlevelsof3and4 arenotstrongenoughto interfere1and2?34shouldbepermittedCapturethestrongerframeregardlesswhenitarrives5Introduction–CaptureEffectIffrequencymodulationschemeisusedDirectSequenceSpreadSpectrum(DSSS)TwotransmissionatthesamefrequencyoverlapintimeandreceivedbythesamereceiverSignalsofthestrongertransmissionwillcapturethereceivermodem6Introduction–CaptureEffectModelforthecaptureeffectAreceivercapturesthesignalrifPrsufficientlyexceedsallotherreceivedenergyCaptureRatio:theminimumratioα7Introduction–. CaptureframeCapturethestrongersignalCapturethestrongerframeAlsodependsonThearrivalmomentThecurrentreceivingstateCapabilityofrealizingitisanewframeCapabilityofjumpingtotheappropriatestateOtherwise,bitsofthenewframeareinterpretedasbitsoftheweakerframe8OutlineIntroductionRelatedWorkAnalysisofBlockingProbabilityProtocolDesignPerformanceEvaluation9RelatedWork-,backoffforalongtimetoallowthetransmittertoreceiveCTSOverhearingCTS,backoffforalongtimetoallowthereceivertoreceivetheentiredatapacketandacknowledgeitSendersdoNOTusecarriersenseLessrestrictiveonblockingassessment10