空间通信协议翻译.docx

空间通信协议翻译.docx

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空间通信协议翻译

SpacecommunicationsprotocolSCPS/CCSDSResearch

YeXiaoguo

（NanjingUniversityofPostsandTelecommunicationsComputerScience,Nanjing,JiangsuProvince210003）

Abstract:

Withthecountriesintheexplorationofouterspaceresources,thedevelopmentanduseofspacecommunicationssystemsandtheirinterconnectiontechnology.Researchanddevelopmentaremoreandmoreattention.SpaceDataSystemsAdvisoryCommittee（ofCCSDS）telemetry,remotecontrolandhighLevelintherailsystem（AOS）hasmade​​aseriesofproposedstandards,includingtheTM/TC/theAOSSpaceDataLinkProtocol,spaceCommunicationsystemnetworkingprotocolsaswellasspacesystems,end-to-endapplicationprotocol.ThispaperanalyzestheCCSDSspacecommunicationssystem.Systemarchitecture,aswellastheSpaceCommunicationsProtocolStandards（SCPS）protocolsystemtoexploretheSCPS,/ofCCSDSSpaceCommunications.Protocolfamilyconfigurationexamples,andconductedin-depthtechnicalanalysis.

Keywords:

forSpaceDataSystemsAdvisoryCommittee（ofCCSDS）;SpaceCommunicationsProtocolStandards（SCPS）;satellitenetwork;Inter-satellitelinks.

Introduction

SpaceDataSystemsAdvisoryCommittee（ofCCSDS）referencetoopentheDepartmentofMarketingInterconnectionReferenceModel（OSI-RM）,hierarchicalthinking,aSpacecommunicationsprotocolsuite[1],forspacelinksorspacenetworkcommunications.

   Earlyinthespacecommunicationssystems,spacevehicle.Thetelemetrydataisbasedontime-divisionmultiplexingwaythroughthefixed-lengthframes.Delivery,re-usespacelinkbycustomrules.Lackofrelevantinternational.Standards,eachspacevehicledatacommunicationsystemprojectcanonlybedeveloped.Customizedsystemfortheprojectindependently,poorreusability,R&Dweek.Alongperiod,aseriouswasteofmanpower,materialresources.

   Theearly1980s,CCSDSpackettelemetry（PacketTelemetry）protocol[2].Packettelemetrysystem,staronset.Equipmentandsubsystemdatasourcepacketdataunitthrough.Fixed-lengthtransmissionframe（TransferFrame）issuedinthespacelink.Send.Sourcepacketlengthvariable,compatibility,andthusthestandard.Spaceprojectsadopted.Sincethen,CCSDSpacketremoteControlProtocol（Telecommand）[3]andadvancedstandardsintherailsystem（AOS）[4]..AOSextensionpackettelemetrystandardscanbeusedtotransferfiles,audio,Videoandothertypesofonlinedata.

   CCSDSpackettelemetrylater,remotecontrolandAOS.Standardsremodeling,spacePacketProtocol（SPP）,TM,/TC/theAOSSpaceDataLinkProtocol（SDLP）,TM/TCsynchronization.AndChannelCoding（SCC）protocolstandardthatreplacesstandard.Standards.Inaddition,CCSDSdevelopedoneforthespacevehicleRFstandardsofcommunicationbetweenthegroundstation---RFandmodulationsystems.ThestandardspecifiesthephysicalRFsignaltosenddatalinkframeLayercharacteristics.

  Inthe1990s,CCSDShasdevelopedasetofspacethrough.Communicationprotocolspecification（SCPS）.SCPSprotocolsuite,including:

SCPS,-NP,SCPS,-SP,SCPS,-TPandSCPS,-FPprotocol.SCPSprotocol.BasedontheTCP/IPprotocol,andthespecificneedsforspacemissions,TCP/IPprotocolhasbeenmodifiedandextendedtosupportfiles,image.Thespatialdatacommunications.

   ACCSDSprotocolarchitecture,Part2Sectiongivesthespatialconfigurationofthecommunicationprotocolinstance,section3SCPS,/ofCCSDSprotocolsuiteoftechnicalanalysis,foursummaryfulltext.

1CCSDSprotocolarchitecture

Spacecommunicationsprotocolarchitectureofbottom-upinclude:

physicallayer.Thedatalinklayer,networklayer,transportlayerandapplicationlayer.Amongthem,eachlayer.Theagreementalsoincludesanumberofavailablecombinations.TheparametersoftheSpaceCommunicationsProtocol..

1）physicallayer

TheCCSDSprovisionsoftheRFandmodulationsystemsforspaceflight.Withthegroundstationlinkbetweenthephysicallayerstandards.Amongthem,theProx-1o-.Near-spacelinkprotocolprovidesforthephysicallayercharacteristicsoftheadjacentspacelink.

2）datalinklayer

CCSDSdatalinklayerdefinesthedatalinkprotocolsublayer.Andsynchronizationandchannelcodingsub-layer.Thedatalinkprotocolsublayerprovides.Transferhigh-leveldataunit.Datalinklayertosendtheframetothetransmissionunit.Synchronizationandchannelcodingsub-layerprovidesthespacelink.Onthetransmissionframesynchronizationandchannelcoding.

   CCSDShasdevelopedadatalinklayerprotocolsublayerofthefollowingfourkindofagreement:

TMspacedatalinkprotocol,theTCSpaceDataLink.Theagreement,AOSSpaceDataLinkProtocol,andProx-1space,chain.Thedatalinklayeroftheroadagreement.Theseprotocolsinasinglespace.Linkdatatransmissionfunction,collectivelyreferredtoasspatialdatalinkprotocol.（SDLP）.Correspondingly,CCSDShasalsodevelopedadatalinklayer.Synchronizationandchannelcodingsub-layerthreecriteria:

TMSynchronizationandChannelCoding,TCSynchronizationandChannelCoding,andProx-1spacelinkco-Proposedcodingandsynchronizationlayerstandards.TMandAOSspacedatalink.AgreementbasedontheTMsynchronizationandchannelcodingstandard.TCspatialdata.LinkprotocolsynchronizationandchannelcodingstandardbasedontheTC.Prox-1null.Inter-linkprotocoldatalinklayerandphysicallayerfunctions[5],Prox-1spacelinkprotocoldatalinklayerbasedontheProx-1Codingandsynchronizationlayer.

3）networklayer

RoutingofnetworklayerspacecommunicationsprotocolforSpaceDataSystems.Function.Spacedatasystems,includingsubnetsatelliteandgroundsubnetthetwoParts.CCSDSdevelopedtwonetworklayerprotocols:

spatialgroupingAssociationTheproposedSPPandSCPS,-NP.ThenetworklayerprotocoldataunitsthroughtheemptyBetweenthedatalinkprotocoltransmission.Insomecases,thespacepacketprotocolSPPprotocoldataunit,thesourceanddestinationaddressescanbeidentified.Fortheapplicationprocess,theagreementbothasanetworklayerprotocol.Meetingasanapplicationlayerprotocol.InternetIPv4andIPv6packet.Canalsobespacedatalinkprotocoltransmission,andtheSPP,SCPS,-NPcanreuseoralonewiththespacedatalink.

4）transportlayer

CCSDShasdevelopedatransportlayerSCPS,-TPprotocoltospaceCommunicationsuserstoprovideend-to-endtransportservice.CCSDShasalsodevelopedaCFDPfiletransferprotocol,CFDPprovidesthetransportlayerFunction,butalsoprovidesapplication-layerfilemanagementfunctions.TransportlayerprotocolPDUusuallybythenetworklayerprotocol,insomecasescanalsoDirectlyfromspacedatalinkprotocoltransmission,theInternet'sTCPUDPcanbebasedontheSCPS,-NP,IPv4orIPv6.

   SCPSSecurityProtocol（SCPS-SP）andtheInternetsecurityprotocol.（IPsec）andtransportprotocolcanbeusedinconjunctionwithend-to-enddataProtection.

5）theapplicationlayer

Spacecommunicationprotocolofapplicationlayerend-to-endapplicationservertoprovideuserswithServices,suchasfiletransferanddatacompression.CCSDShasdevelopedthreeshouldbeLayerProtocol:

SCPS,fileprotocolsSCPS,-FP,losslessdatacompression.Reduction,imagedatacompression.Eachspaceprojectscanalsobeusednon-CCSDS.Theproposedapplication-specificprotocolstomeetthespecificneedsofthespaceprojectRequirements.TheapplicationlayerPDUisusuallytransmittedbythetransportlayerprotocol,insomecases.Canalsodirectlytransmittedbythenetworklayerprotocol,Internet.TheagreementcanalsobebasedonSCPS,-TP,TCP,theUDP.Amongthem,CCSDS.FileTransferProtocolCFDPtransportlayerandapplicationlayerfunctions.

CCSDSdoesnotgivespacecommunicationprotocols,applicationprogramminginterfaces.Interface（API）intheformofdefinitions,buttheserviceisgivenintheformofprimitive.Definition.Amongthem,theprimitiveisanabstractoftheAPI,donotrelyInanyspecificimplementationtechnology.

2.SpaceCommunicationProtocolconfigurationexamples

IfthenumberbeingcalledisatraditionalPSTNtelephone,thetrunkproviderroutestheIPpacketstoaPSTNGatewaythatisclosesttothenumberbeingcalled,tominimizepossiblelongdistancecharges.TheprovidercanalsoterminatePSTNnumbers,androuteincomingcallsforthosenumbersbacktotheIPPBXovertheSIPcanalsoTrunk.Thisallowsbusinessestoofferlocalphonenumbersinseveralgeographicalareas,butservicethemallfromasinglelocation.

IfthenumberbeingcalledcanbereachedoveraSIPTrunk,thecalldoesnotneedtoberoutedoverthePSTN,butcanbecarriedontheIPnetworkendtoend.Providerscandeliverthesecallstotheircustomersforverylittlecost,andmanyofferthematnocharge.SomeserviceprovidershaveagreementsandexchangecallsforeachotherscustomersdirectlyovertheirIPnetworks.Wherenosuchagreementsareinplace,callsareroutedoverthePSTN,eventhoughbothendpointsmayultimatelybereachableoveraSIPTrunk.

TheSIPTrunkcanbeprovidedbytheInternetServiceProvider,orbyanindependentInternetTelephonyServiceProvider.Infact,therecanbeseveralpartiesinvolved,eachoneprovidingadifferentpartoftheserviceneededtodelivertheend-to-endcommunication:

Internetaccess,SIPtermination,PSTNgateway,etc.

BecauseaSIPTrunkisnotaphysicalconnection,thereisnoexplicitlimitonthenumberofcallsthatcanbecarriedoverasingletrunk.Eachcallconsumesacertainamountofnetworkbandwidth,sothenumberofcallsislimitedbytheamountofbandwidththatcanflowbetweentheIPPBXandtheprovider’sequipment.

Formarketingreasons,manyprovidersassociateaSIPTrunkwithasinglephonecall.Whenyoupurchasesuch