The Transmission Control Protocol (TCP) represents the most deployed transport protocol used in the Internet so far. This popularity motivates its presence in wireless networks, including ad hoc networks. These networks are very promising since they make i
Fig.9(b)showsthattheaggregatethroughput,whichisthecapacityofthenetwork,isnearlythesameofthatobtainedinFig.9(a)inwhichonlyone owiscrossingthenetwork.Thedifferencebetweenthetwo avors,usingornotDA,istoosmalltoseefromthe gures.Onceagain,theDAoptionprovidedbetterresultforboth avors.Fig.9showsimprove-mentofupto7%,whichisnotverysigni cant.AmongtheTCP avorsthedifferenceiscompletelynegligible.
VI.CONCLUSIONS
Inthiswork,wehaveinvestigatedtheperformanceofTCPNewrenoandTCPSACKoveradhocnetworks.ns2wasusedforsimulatingthedifferentscenarios.Weusedthreemetrics:energyconsumption,throughputandretransmissionswithorwithoutdelayedacknowledgmentoptionDA.Weobservedthefollowing:
Theenergyconsumedatthesenderwasinverseleyproportionaltothepacketsizeregardlessofthe avor.
Theenergyconsumptionincreasedwithlossesforboth avorsaswell.
Thelossesincreasedtheretransmissionsnumberinallcases.
ThetwoTCP avorswithDAoptionspentingenerallessenergyandachievedbetterthroughputinmanycases.However,theDAoptiondidnotguaranteethebestresultinallcircumstances.
ThedifferencebetweentheTCP avorsperformancesweremoreperceptiveinthesimulationswithlosses.
TCPSACKperformedslightlybetterthanTCPNewrenoforlargepacketsizes.
Becauseofthelackoftime,weevaluatedonlyTCPNewrenoandTCPSACKprotocolswithorwithoutDAoption.IngeneraltheresultsdidnotshowusmeaningfuldifferencesbetweenthetwoTCP avors.AlthoughTCPSACKusestheselectiveacknowledgmentstrategy,itdidnotoutperformedTCPNewrenoinmostcasesasexpected.Therefore,thegeneraloutcomeisthatthetwo avorsworkquitethesameintheevaluatedscenarios,anddelayedacknowledgmentisindeedhelpfulinadhocnetworkswithouthighlevelofbiterrors.Forfuturework,moresimulationrunsanddifferentscenarioswithothermetricscouldbeconsidered.
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