无线传感器网络时间同步

Vol.6No.4InformationTechnologyLetterJul.200812NTP1GPS2NTP[1]UTC3NTPNTPGPSGPS1Networktimeprotocol2GlobalPositioningSystem3CoordinatedUniversalTime12GPSGPS100NTPGPS(1).Sendtime4Accesstime5Transmissiontime6Propagationtime7Receptiontime8Receivedtime9(2).GPS(3).(4).NTPNTP345678913Vol.6No.4InformationTechnologyLetterJul.20083.1TPSN10DMTSDelayMeasurementTimeSynchronization[2]UCLANESL,NetworkedandEmbeddedSystemsS.Ganeriwal[3]-1NTPNTP1T1T4AT2T3BABBT2AT2T3AT4∆AT1ABT1~T4AT4BddTT+∆+=12dTT+∆−=342)()(3412TTTT−−−=∆2)()(3412TTTTd−+−=T4A∆BNTP3.2LTS11LTS[4]TPSNLTSLTS10Timing-syncProtocolforSensorNetworks11LightweightTree-basedSynchronization14[4]Distributeddepthfirstsearch(DDFS)EchoLTSTPSNLTS3.3RBS12NTP[5]232---2---3.4HRTS13nn-1[6]33BSn1n212ReferenceBroadcastSynchronization13HierarchyReferencingTimeSynchronizationProtocol15Vol.6No.4InformationTechnologyLetterJul.200813BS1ABSn11Bn2'2T2n1BS2T3T3BSn13BSn1∆4BS∆2T5n1n2n1∆BS∆−−'22TTBSLTSLTS14LTS3.5Tiny-Sync/Mini-SyncTiny-SyncMini-Sync[7]1T2T122121)()(btTatT+=a12b1241221oT4Tiny-SyncMini-SyncbT12rT14BreadthFirstSpanningTree161212bTaTbo+1212bTaTbr+(,,)aoTbTrT12b125,,abToTbTrT12b12a12b12513Tiny-Sync4Mini-SyncTiny-Sync5Tiny-Sync/Mini-SyncTiny-SyncMini-Sync4MACMica217Vol.6No.4InformationTechnologyLetterJul.2008[1]L.,M.D.,Networktimeprotocol(Version3)specification,implementationandanalysis.1992,UniversityofDelaware,DARPANetworkWorkingGroup.[2]Ping,S.,DelayMeasurementTimeSynchronizationforWirelessSensorNetworks.2003,IntelResearch.[3]Saurabh,G.,K.Ram,andB.S.Mani,Timing-syncprotocolforsensornetworks,inProceedingsofthe1stinternationalconferenceonEmbeddednetworkedsensorsystems.2003,ACM:LosAngeles,California,USA.[4]Janavan,G.andR.Jan,Lightweighttimesynchronizationforsensornetworks,inProceedingsofthe2ndACMinternationalconferenceonWirelesssensornetworksandapplications.2003,ACM:SanDiego,CA,USA.[5]Jeremy,E.,G.Lewis,andE.Deborah,Fine-grainednetworktimesynchronizationusingreferencebroadcasts.2002,ACM.p.147-163.[6]Hui,D.andH.Richard,TSync:alightweightbidirectionaltimesynchronizationserviceforwirelesssensornetworks.2004,ACM.p.125-139.[7]M.L.Sichitiu,andC.Veerarittiphan.Simple,accuratetimesynchronizationforwirelesssensornetworks.inWirelessCommunicationsandNetworking,2003..18