移动自组织网络

JieWuDepartmentofComputerandInformationSciencesTempleUniversityPhiladelphia,PA19122CIS9590AdHocNetworks(PartII)TableofContentsIntroductionInfrastructurednetworksHandofflocationmanagement(mobileIP)channelassignmentTableofContents(cont’d.)InfrastructurelessnetworksWirelessMAC(IEEE802.11andBluetooth)AdHocRoutingProtocolsMulticastingandBroadcastingSecurityNetworkCodingTableofContents(cont’d.)Infrastructurelessnetworks(cont’d.)PowerOptimizationApplicationsSensornetworksandindoorwirelessenvironmentsPervasivecomputingSocialnetworksSampleon-goingprojectsAdHocWirelessNetworks(Infrastructurelessnetworks)Anadhocnetworkisacollectionofwirelessmobilehostformingatemporarynetworkwithouttheaidofanycentralizedadministrationorstandardsupportservicesregularlyavailableonthewideareanetworktowhichthehostsmaynormallybeconnected(JohnsonandMaltz)AdHocWirelessNetworks(Infrastructurelessnetworks)Manet(mobileadhocnetworks)MobiledistributedmultihopwirelessnetworksTemporaryinnatureNobasestationandrapidlydeployableNeighborhoodawarenessMultiple-hopcommunicationUnitdiskgraph:hostconnectionbasedongeographicaldistanceSampleAdHocNetworksSensornetworksIndoorwirelessapplicationsMeshnetworksPeople-basednetworks“smallworld”thatareverylargegraphsthattendtobesparse,clustered,andhaveasmalldiameter.“sixdegreeofseparation”Self-organizing:withoutcentralizedcontrolScarceresources:bandwidthandbatteriesDynamicnetworktopologyCharacteristicsUnitDiskGraphFigure1:Asimpleadhocwirelessnetworkoffivewirelessmobilehosts.Defenseindustry(battlefield)LawenforcementAcademicinstitutions(conferenceandmeeting)PersonalareanetworksandBluetoothHomenetworkingEmbeddingcomputingapplicationsHealthfacilitiesDisasterrecovery(search-and-rescue)ApplicationsApplicationsMobilitymanagementAddressingandrouting*LocationtrackingAbsolutevs.Relative,GPSNetworkmanagementMergeandsplitResourcemanagementNetworksresourceallocationandenergyefficiencyQoSmanagement*DynamicadvancereservationandadaptiveerrorcontroltechniquesMajorIssuesMACprotocols*Contentionvs.contention-freeApplicationsandmiddlewareMeasurementandexperimentationSecurity*Authentication,encryption,anonymity,andintrusiondetectionErrorcontrolandfailureErrorcorrectionandretransmission,deploymentofback-upsystemsNetworkcodingReducenumberoftransmissionsMajorIssues(Cont’d.)IssuestobeCoveredWirelessMediaAccessProtocols(MAC)AdHocRoutingProtocolsMulticastingandBroadcastingPowerOptimizationSecurityNetworkCodingWirelessMACAMAC(MediaAccessProtocol)isasetofrulesorprocedurestoallowtheefficientuseofasharedmedium.•Contentionvs.contention-free•Sender-initiatedvs.receiver-initiatedWirelessMAC:MajorIssuesDistributedoperationsSynchronizationHiddenterminalsExposedterminalsThroughputAccessdelayFairnessReal-timetrafficResourcereservationAbilitytomeasureresourceavailabilityPowerandratecontrolDirectionalantennasWirelessMACContention-basedALOHA:nocollisionavoidancePure:transmittedatarbitrarytimeSlotted:transmittedatstartofatimeslotp-persistent:slottedandtransmittedwithaprobabilitypWirelessMACCarrierSenseMultipleAccess(CSMA):listentodeterminewhetherthereisactivityonthechannelPersistent:continuouslylistensNonpersistent:waitsarandomamountoftimebeforere-testingp-persistent:slottedandtransmitwhenidlewithaprobabilityofpWirelessMACContention-freeprotocolsBit-mapprotocol:eachcontentionperiodconsistsofNslots.Binarycountdown:usebinarystationaddressinbidding.HybridMixedcontention-freewithcontentionWirelessMACHiddenTerminalProblem•Twonodes,hiddenfromoneanother(outoftransmissionrange),attempttosendinformationtothesamereceivingnode.•Packetcollisions.ExposedNodeProblem•Anodeisinhibitedfromtransmittingtoothernodesonoverhearingapackettransmission.•Wastedbandwidth.WirelessMACSender-initiated•MACA(MultipleAccesswithCollisionAvoidance)(RTS-CTS-data)•MACAW(MACAwithAcknowledgement)•BTMA(BusyToneMultipleAccess)•DBTMA(DualBTMA)Receiver-initiated•MACA-BI(ByInvitation)Otherextensions•MarchandPAMASMACA(P.Khan)Nocarrier-sensingforchannelTwospecialsignals•RTS:request-to-send•CTS:clear-to-sendPacketlost•Binaryexponentialback-upOvercomesthehiddenterminalissueSamplecollisionRTS-CTSproblem1SamplecollisionRTS-CSTproblem2MACAW(S.ShenkerandL.Zhang)RTS+CTS+DS+DATA+ACK•DS:data-sending(avoidunnecessaryback-offcounterbuildup)RRTS:request-for-request-to-sendDistinctback-offcounterperflowDBTMA(Z.Haas)BTMA(BusyToneMultipleAccess)•Separatecontrolanddata(busytone)•Nodessensedatacarryalsosendbusytone•Toorestrictive(Disabletwo-hopneighbors)DualBTMA•RTS•Receivebusytone+CTS•Transmitbusytone+DataMACA-BI(M.Gerla)Receiver-initiated•RTR:ready-to-receive•Data:datatransmissionMARCH(C.T.Toh)MediaAccesswithReducedHandshake(MARCH)PAMAS(C.S.Raghavendra)Power-AwareMulti-AccessProtocolwithSignaling(PAMAS)Temp.reducingtransmitterrangeTurnoffOthers(N.H.Vaidya)Differentranges•TR:transmissionrange,IR:interferencerange,SR:sensingrange(TRIRSR)•DifferentrangesforRTS,CTS,Data,andAckDirectionalantennas•DO(sender:omni(