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Protocol Design and Analysis for Cooperative Wireless Networks PDF

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Wireless Networks Wei Song Peijian Ju A-Long Jin Protocol Design and Analysis for Cooperative Wireless Networks Wireless Networks SeriesEditor XueminShermanShen UniversityofWaterloo,Waterloo,Ontario,Canada Moreinformationaboutthisseriesathttp://www.springer.com/series/14180 Wei Song • Peijian Ju (cid:129) A-Long Jin Protocol Design and Analysis for Cooperative Wireless Networks 123 WeiSong PeijianJu FacultyofComputerScience IBMCanada UniversityofNewBrunswick Fredericton,NB,Canada Fredericton,NB,Canada A-LongJin UniversityofWaterloo Waterloo,ON,Canada ISSN2366-1186 ISSN2366-1445 (electronic) WirelessNetworks ISBN978-3-319-47725-1 ISBN978-3-319-47726-8 (eBook) DOI10.1007/978-3-319-47726-8 LibraryofCongressControlNumber:2016954727 ©SpringerInternationalPublishingAG2017 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. Thepublisher,theauthorsandtheeditorsaresafetoassumethattheadviceandinformationinthisbook arebelievedtobetrueandaccurateatthedateofpublication.Neitherthepublishernortheauthorsor theeditorsgiveawarranty,expressorimplied,withrespecttothematerialcontainedhereinorforany errorsoromissionsthatmayhavebeenmade. Printedonacid-freepaper ThisSpringerimprintispublishedbySpringerNature TheregisteredcompanyisSpringerInternationalPublishingAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Preface Cooperativewirelessnetworkshaveemergedasapromisingtechnologythatallows wirelessdevicestotakeadvantageofdiversityandthebroadcastnatureofwireless medium. Nonetheless, some important issues remain to be addressed to enable practical implementation. In particular, with the fast-growing mobile traffic and rising energy costs, energy saving needs to be taken into account in the design of cooperative protocols. In addition, many designs and analyses assume that the locations of cooperative wireless nodes are deterministic or known a priori. However, due to user mobility and/or network dynamics, the node locations are spatially random. Hence, this feature should be properly incorporated into the protocoldesignandanalysisforcooperativewirelessnetworks. In this book brief, we focus on the design and analysis of protocols for cooperative wireless networks, especially, at the medium access control (MAC) layer and cross-layer design between the MAC layer and the physical layer. It first provides a comprehensive review of existing studies in the literature and points out the problems that are worth further investigation. Then, it introduces severalnovelsolutionsforcooperativewirelessnetworkprotocols,aimingtoreduce energy consumption and address spatial random distribution of wireless nodes. For each solution, it gives a clear system model and problem formulation, details of the proposed cooperative schemes, comprehensive performance analysis, and extensive numerical and simulation results that validate the analysis and examine the performance under various conditions. At the end of this book brief, we also highlight several interesting directions on cooperative wireless networks that deservefutureexploration. Fredericton,Canada WeiSong Fredericton,Canada PeijianJu Waterloo,Canada A-LongJin v Contents 1 Introduction .................................................................. 1 1.1 Motivations.............................................................. 1 1.2 Challenges............................................................... 2 1.2.1 EnergySavingwithSpatiallyRandomRelays................ 2 1.2.2 CooperativeDiversitywithMultipleRelays .................. 2 1.3 Outline................................................................... 3 References..................................................................... 4 2 RelatedWorksonCooperativeWirelessNetworks ...................... 7 2.1 CooperativeCommunications.......................................... 7 2.2 CooperationScenarios.................................................. 9 2.3 ThreeCategoriesofCooperativeMACProtocols..................... 12 2.3.1 Category-I....................................................... 13 2.3.2 Category-II...................................................... 15 2.3.3 Category-III..................................................... 17 2.4 ResearchIssuesforMAC-LayerCooperation......................... 19 2.4.1 NewCategories................................................. 19 2.4.2 CooperativeDiversity .......................................... 20 2.4.3 UserMobility ................................................... 21 2.4.4 EnergySaving................................................... 22 References..................................................................... 23 3 Energy-EfficientUncoordinatedCooperativeMACwith UncertainRelayDistributionIntensity.................................... 27 3.1 MotivationandOverview............................................... 27 3.2 SystemModelandProblemFormulation.............................. 28 3.2.1 SystemModel................................................... 28 3.2.2 ProblemFormulation........................................... 31 3.3 RelayIntensityEstimation.............................................. 32 3.4 Energy-EfficientCooperativeSchemeandItsAnalysis............... 37 3.4.1 AnEnergy-EfficientCooperativeScheme..................... 37 3.4.2 AnalysisofCollisionProbability .............................. 41 vii viii Contents 3.5 NumericalandSimulationResults..................................... 43 3.5.1 RelayIntensityEstimation ..................................... 43 3.5.2 EnergySavingStrategy......................................... 44 3.5.3 PerformanceEvaluation........................................ 46 3.6 Summary ................................................................ 49 AppendixA:ExtendedProofofLemma3.2withN Relays................ 49 AppendixB:Proofof(3.34)and(3.35)...................................... 50 References..................................................................... 51 4 Energy-Aware Cooperative MAC with Uncoordinated GroupRelays................................................................. 53 4.1 MotivationandOverview............................................... 53 4.2 SystemModelandProblemFormulation.............................. 54 4.2.1 SystemModel................................................... 54 4.2.2 ProblemFormulation........................................... 56 4.3 Energy-AwareCooperationStrategy................................... 57 4.3.1 CooperationCriteria............................................ 57 4.3.2 DistributedCooperationStrategy.............................. 58 4.4 PerformanceAnalysis................................................... 60 4.4.1 UpperBoundofCollisionProbability......................... 60 4.4.2 LowerBoundofTransmissionSuccessProbability........... 63 4.4.3 UpperBoundofTransmissionSuccessProbability........... 64 4.5 NumericalandSimulationResults..................................... 65 4.5.1 TransmissionSuccessProbability.............................. 67 4.5.2 AverageDelayandDelayOutageProbability................. 67 4.5.3 EnergySavingandEnergyBalance............................ 69 4.5.4 Scalability....................................................... 71 4.6 Summary ................................................................ 73 AppendixA:Proofof(4.17).................................................. 73 AppendixB:Proofof(4.25).................................................. 74 References..................................................................... 75 5 OpportunisticCooperativeRelayingwithBackoff-Based Contention.................................................................... 77 5.1 MotivationandOverview............................................... 77 5.2 SystemModel........................................................... 78 5.3 CooperativeRelayingStrategies ....................................... 80 5.3.1 Inter-GroupBackoff-BasedContention ....................... 81 5.3.2 Intra-GroupContention......................................... 81 5.4 PerformanceAnalysis................................................... 83 5.4.1 ProbabilityDistributionsofSpatialRandomRelays.......... 84 5.4.2 PerformanceofTwo-LevelBackoff-BasedStrategy.......... 86 5.4.3 PerformanceofHybridRelayingStrategy..................... 89 5.5 NumericalResultsandDiscussions.................................... 90 5.5.1 CDFofTransmissionSuccessProbability .................... 91 5.5.2 PerformanceUpperandLowerBounds ....................... 93 Contents ix 5.5.3 RelaySuccessProbability...................................... 94 5.5.4 BackoffDelayofRelaySelection.............................. 98 5.6 Summary ................................................................ 100 Appendix:CalculationoftheCDFF(cid:2);l.x/of(cid:2)RD;l.......................... 101 References..................................................................... 103 6 DiversityRelayingwithSpatiallyRandomMobileRelays.............. 105 6.1 MotivationandOverview............................................... 105 6.2 SystemModel........................................................... 107 6.2.1 ChannelModel.................................................. 107 6.2.2 MobilityModelandPoissonPointProcess ................... 108 6.2.3 DistributedCooperativeTransmission......................... 108 6.2.4 MACforMulti-HelperCoordination.......................... 109 6.2.5 MRCandUpperBoundofTotalSNR......................... 111 6.3 UnconditionalSuccessProbabilityandDelay......................... 112 6.3.1 ExactUnconditionalPDFofSNRUpperBound ............. 112 6.3.2 ApproximateUnconditionalPDFofSNRUpperBound..... 114 6.3.3 ApproximationofUnconditionalSuccessProbability........ 115 6.3.4 DelayAnalysisofMACCoordinationSchemes.............. 116 6.3.5 Outage-DelayTradeoff......................................... 118 6.4 NumericalandSimulationResults..................................... 119 6.4.1 AnalysisValidation............................................. 120 6.4.2 Outage-DelayTradeoff......................................... 123 6.5 Summary ................................................................ 124 Appendix:ProofofLemma6.1............................................... 125 References..................................................................... 126 7 ConclusionsandFutureDirections ........................................ 129 7.1 Conclusions ............................................................. 129 7.2 FutureWork............................................................. 130 Chapter 1 Introduction 1.1 Motivations Inthepastdecade,wirelessnetworkshavebeenwidelystudiedandused.However, wirelesscommunicationsfaceseveralchallengingissueswhicharenotimposedin wirednetworks,suchasmobility,powerconsumption,interferenceandreliability. Besides, signal fading is often a problem in wireless networks, which is caused bymultipathpropagation andshadowing. Todeal withthesechallenges, attractive techniques, such as multiple input and multiple output (MIMO) and coopera- tive communications [4, 7], have been developed by exploiting spatial diversity. Nonetheless, due to the size, cost and energy limitations of mobile devices, it can be infeasible to deploy multiple antennas in some wireless terminals. In order to meet the needs of future wireless networks, user cooperation [13] is studied as a promising low-cost technique to provide spatial diversity. Taking advantage of the inherentbroadcastingnatureofthewirelessmedium,thenodeswithgoodchannel conditions can forward the overheard data to facilitate the transmission between source(S)anddestination(D). Originally, most of the research works focus on the physical layer cooperation [4, 7], where the cooperative schemes pay more attention to the various methods of signal processing at the relay node and signal combination at the destination node. With physical layer cooperation, either diversity or multiplexing can be achieved,whichimprovesthequalityofcommunicationsintheupperlayers.Since multiple cooperative nodes are available during packet transmission, it is vital to coordinatethesenodestoaccessthechannelinacooperativefashion.Toachievethe cooperationgainatupperlayers,considerableresearchattentionhasbeenattracted to the medium access control (MAC) layer [6, 9]. Different from physical layer cooperation, MAC layer cooperation needs to figure out when to cooperate and whomtocooperatewith. Whilecentralizedsolutions[2,5,6]canrelyonacentralcontrollertodetermine the best relays, distributed solutions also attract considerable research attention ©SpringerInternationalPublishingAG2017 1 W.Songetal.,ProtocolDesignandAnalysisforCooperativeWirelessNetworks, WirelessNetworks,DOI10.1007/978-3-319-47726-8_1 2 1 Introduction duetolightweightsignalingandgoodscalability.Intheprobability-basedschemes [10–12], each relay that successfully overhears the data from the source indepen- dently determines a forwarding probability by synthesizing a variety of factors. In thebackoff-basedschemes[1,8],eachrelaymakesuseoflocalinformationtotune abackofftimesothatabestrelaywithasmallestbackofftimewinsthecontention toforwardtheoverhearddata.AlthoughcooperativeMAChasbeenwidelystudied, manypracticalissuesremaintobeaddressed. 1.2 Challenges 1.2.1 EnergySavingwithSpatiallyRandomRelays Withrisingenergycostsandrigorousenvironmentalstandards,greencommunica- tionsbecomeanewresearchtrendinrecentyears,especially,toaccommodatethe fast-growing multimedia services in wireless networks, since mobile devices are usuallyenergy-constrained.Hence,howtoreduceenergyconsumptionisacritical issue for MAC layer cooperation. Besides, many existing works assume that the networktopologyisknownapriori[10]andfocusonthethroughputperspective[6]. It is vital to relax the assumption of deterministic known topology and take into accountrelayingnodesthatarerandomlydistributedinaspatialarea. 1.2.2 CooperativeDiversitywith MultipleRelays AsmotivatedbydiversityandMIMO,cooperativerelaylinksandthedirectlinkcan beusedtotransmitthesamepackettoachievediversity.Akeyproblemistochoose a good criterion to start cooperation. Cross-layer techniques can be employed to dynamicallyestimatethechannelcondition.Ifatransmissionfailureisverylikely to happen with a poor direct link condition, cooperative diversity transmission is initiatedtosatisfycertainQoSrequirements[2].Whetherthesourceshouldalways enablediversitytransmissionoronlyactivateitondemanddependsonfactorssuch astheenergyconsumptionandavailabilityofhelpers. Another essential question to exploit diversity gain is the selection of a single optimalhelperormultipleuncorrelatedhelperswithlimitedinterferenceandpower consumption. From the physical-layer standpoint, multiple helpers can improve diversity to achieve a higher signal-to-noise ratio (SNR) and better performance. However, from the link layer’s point of view, multiple relays may not perform better than a single best relay, because of the overhead to coordinate multiple relays and manage transmissions. Intuitively, the more helpers, the more complex the coordination. Besides, multiple helpers may increase energy consumption and possibilities of collisions (e.g., due to the hidden terminal and exposed terminal problems).

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