星地融合通信白皮书 Integrated Terrestrial-Satellite Communication (ITSC)

IntegratedTerrestrial-Satellite

Communication(ITSC)

WHITEPAPER

Copyright©CICTMOBILECO.,LTD.AllRightsReserved.NopartofthiswhitepapermaybereproducedortransmittedinanyformorbyanymeanswithoutpriorwrittenconsentofCICTMobileCo.,LTD.

CONTENTS

Chapter1：Introduction 02

Chapter2：Drivingforce,application

scenariosandvision 04

2.1.DrivingforceofITSC05

2.2.TypicalapplicationscenariosofITSC05

2.3.VisionofITSC06

Chapter3：Keyperformanceindicators

andtechnicalchallenges 08

3.1.Keyperformanceindicator(KPI)09

3.2.Technicalchallenges10

3.3.KPIsandtechnicalchallengesforDS2MPC12

Chapter4：RoadmapforITSC 13

Chapter5：KeytechnologiesofITSCsys-

tem 16

5.1.Networkarchitecture17

5.2.Wirelesstransmissiontechnology18

5.2.1.Duplexmode18

5.2.2.Waveformandmultipleaccesstech-

nology19

5.2.3.Beammanagement19

5.2.4.Linkandcoverageenhancement20

5.2.5.UEpositioning21

5.3.Mobilitymanagement22

5.3.1.Inter-satellitehandover22

5.3.2.UElocationmanagementandpag-

ing22

5.3.3.Roaming23

5.4.Networkandsecuritytechnology24

5.4.1.Flexibledeploymentofnetwork

functions24

5.4.2.Slicingtechnology25

5.4.3.Networkvirtualization25

5.4.4.Edgecomputing26

5.4.5.Broadcastandmulticasttechnology27

5.4.6.Security28

5.4.7.Routing29

5.5.Satellite-terrestrialspectrumsharingand

interferenceavoidance30

5.6.Implementationspecificoptimization

technology31

Chapter6：Promotionofstandardiza-

tionandtechnicalverification 32

Summaryandprospect 33

Abbreviations 34

References 36

Introduction

IntegratedTerrestrial-SatelliteCommunication(ITSC)

Today,existingterrestrialmobilecommunica-tionnetworks,including3G/4G/5G,coverap-proximately70%ofthepopulation.However,achievingcost-effectivecoverageinareassuchasspace,oceans,forests,deserts,andremoteregionsremainschallenging.Satellitecommu-nicationpresentsaviablesolutionforwideareacoverage.Advancementsinsatellitetechnology,suchasthelaunchofmultiplesatellitewithinasinglerocketandthedevelopmentofrecoverablelaunchingvehicles,havesignificantlyreducedthecostofsatellitesdeployment.Meanwhile,satellitecommunicationsystemshaveeffective-lyaddressedissuesrelatedtouseraccess,callquality,datatransmissionandconstructioncosts.Therefore,tomeettheexpandingneedsofhu-manactivitiesandalignwiththevisionof6Gfor“globalcoverage,context-awareconnection”[1],theintegrationofterrestrialcommunicationandsatellitecommunication(alsoknownasIntegratedTerrestrial-SatelliteCommunica-tion,ITSC)isemergingasacrucialtrend[2~5].

SignificantprogresshasbeenmadetoenablingITSCfromtheoreticalconcepttopracticalreali-ty.InJune2022,the3rdGenerationPartnership(3GPP)finalizedthestandardizationofNon-Terres-trialNetwork(NTN)[6~8]inRel-17,pavingthewayforrealdeploymentofNTNnetwork.Additionally,theconceptofDirectSatellite-To-Mobile-PhoneConnectivity（DS2MPC）,enablingdirectcon-nectivitybetweensatellitesandmobilephones,hasgarneredconsiderableattentionfrombothindustryandacademiaduetoitsportabilityandpotentialforalargesubscriberbase.Furthermore,recentadvancementsincommunication,semi-conductorandsatellitetechnologieshavemadeit

feasibletointegrateterrestrialandsatellitecom-municationwithin6Gframework.Thisintegra-tionwillemployunifiedradioairinterface,unifiedaccessauthentication,andunifiedcorenetworktoachieveseamlessglobalcoverage[9].Consequent-ly,notonlyindividualuserswithmobilephonesinurban,remoteareas,desertsandforests,butalsoindustrialusersutilizingvariouskindsofterminalssuchasairborne,vehicle-mountedorship-mounteddevices,willbenefitfromanintegratedcommunicationservice,facilitatingseamlesshandoversandfreeroamingbetweenterrestrialandsatellitecommunicationnetworks.

ToprovideacomprehensiveunderstandingabouttheITSC,thiswhitepaperwillconducttechnicalanalysisofthedrivingforces,require-ments,applicationscenarios,keyperformanceindicatorsandtechnicalchallenges.Furthermore,itwilloutlinearoadmapforevolutionofITSCfromcurrent5Gstagetofuture6Gstage.ThepaperwilldiscussarangeofkeytechnologiesrelevanttoITSCandsuggestdirectionsforfuturestandardizationandtechnologyverificationef-forts.TheprimaryobjectiveofthiswhitepaperistoofferessentialtechnicalinsightintoITSCandcontributetoitscontinueddevelopment.

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Drivingforce,application

scenariosandvision

IntegratedTerrestrial-SatelliteCommunication(ITSC)

2.1DrivingforceofITSC

Inthepastfewdecades,terrestrialcommuni-cationandsatellitecommunicationhaveun-dergoneindependentdevelopments.Terrestrialcommunicationhasbeenoptimizedfor“higherspectralefficiency”and“highertransmis-sionrate”toadapttoterrestrialchannelandterrestrialbusinessmodels.Similarly,satellitecommunicationhasfocusedon“higherpowerefficiency”and“higherthroughput”tocatertosatellitechannelandsatellitebusinessmod-els.However,drivenbytheincreasingdemandsofpersonalusageandindustrialdevelopment,ITSChasemergedasahotresearchtopicin5G-Advancedand6G.ThefollowingaresomekeydrivingforcesofITSC.

Popularizationofsatellitecommunica-tionusers

Satellitecommunication,oncelimitedtogov-ernmentandmilitaryusers,hasnowbecomeaccessibletoordinaryindividuals.InITSC,mobilephonescanseamlesslyconnecttobothsatelliteandterrestrialbasestations,reducingcostsforusersandenhancingtheirmobileex-perience.

Seamlesscoverageandanytimeany-whereaccessrequirements[1]

Terrestrialcommunicationprovidesbroadbandmobileservicesthroughdensebasestationde-ployment,whilesatellitecommunicationensureswidecoveragethroughsatellitebeams.ITSCen-ablesseamlesscoverageandaccessservicesbyleveragingthestrengthsofbothtechnologies.

IntelligentconnectionofIoTdevices

Internetofthings(IoT)requireslow-costlocalconnectivityaswellaseconomicalwide-areaconnectivitytofacilitaterapidinformationex-changeandsharing.ITSCoferstechnicalcapa-bilitiesfortheintelligentconnectioninremoteareas,medium–to-highaltitudeairspace,andnearspace.

Industrychainsharingbetweenterres-trialandsatellitecommunication

Terrestrialcommunicationestablishedanopenindustrialchainthatservesbillionsofusers.ITSCpresentsanopportunityforoperatorstoleveragetheindustrialchainofterrestrialcom-municationandexpandtheirservicestocoverbothterrestrialandsatelliteservice.

2.2TypicalapplicationscenariosofITSC

ITSCencompassesawiderangeofapplicationscenarios,offeringsolutionsforvariousindus-triesandsectors,includingpersonalmobilecommunications,transportation,aeronauticalandmaritimecommunications,telecommuni-

cations,IoT,aerospaceandemergencyrescue.

Personalmobilecommunicationsce-narios

Mobilephonesaretheprimarycommunication

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toolforindividuals.ITSCenableglobalseamlesscoverageanduninterruptedservicesbyallow-ingaccesstoterrestrialortheon-boardbasestation,facilitatingsmoothhandoversbetweendiferenttypesofbasestations.

Transportationscenarios

ITSCsupportsprofessionalcommunications,databackhaulandnetworkaccessforvehicles,trains,andboats.Terrestrialmobilenetworkscanbeutilizedwithintheircoverage,whilesat-ellitenetworksprovideconnectivityinareasbe-yondterrestrialcoverage.

Aeronauticalandmaritimescenes

Terrestrialcommunicationsprovideservicesforaircraftandshipswhiletheyareatairportsordocks,whilesatellitecommunicationsareusedduringtheirjourneystoenableprofessionalcommunicationsanddatabackhaul.

Telecommunicationscenarios

ITSCofferscost-effectivesolutionsforbasestationbackhaulservices,broadbandaccessandsatelliterelayservicesinremoteareas,islands,offshoreplatformsandmobileplat-forms.Itcanalsoprovidesatelliteconnectivityanddatabackhaulserviceswithouttheneed

fortransformingtheexistingcommunicationnetworks.

IoTintelligentconnectionscenarios

Inordertomeettheneedsoflarge-scaleandlow-costterminalaccess,ITSCcanprovidedirectorindirectconnectionservicesforIoTterminalsonthefixedormobileplatform,suchaspowergridmonitoring,geologicalandforestmonitoring,UAVcontrol,offshorebuoyinfor-mationcollectionandmore.

Navigationandaerospacescenes

ITSCenhancespositioningandnavigationservicesforindividualandprofessionalusers.Furthermore,italsosupportsinformationtrans-missionservicesrelatedtoaerospaceactivities.

Emergencyrescue

ITSCsystem,accessedthroughmobilephones,providenaturaldisasterpredictionservicestoindividualusersandfacilitateessentialcommu-nicationbetweenvictimsandrescueworkersafteradisaster.

Thesediverseapplicationscenariosdemon-stratetheversatilityandpotentialofITSCacrossmultipleindustries,empoweringefficientandreliablecommunicationinvariouscontexts.

2.3VisionofITSC

ThefutureITSCsystemwillencompassathree-dimensionalheterogeneouscommunica-tionnetwork[2],asillustratedinFigure1.Fromtheperspectiveofnetworkelementfunctions,theITSCnetworkcanbedividedintothree

maincomponents:theRadioAccessNetwork(RAN),theBearerNetwork(BN),andtheCoreNetwork(CN).TheRANincludesterrestrial,nearspace,andsatelliteaccess.TheBNcom-prisesspaceandgroundbearers,wherethe

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spacebearerfacilitatestransmissionbetweensatellites,andthegroundbearerhandlestrans-missionbetweengatewaystations.TheCNcon-sistsofcorenetworkelementsandtheIPMul-timediaSubsystem(IMS),withcorenetworkelementsprimarilydeployedontheground(referredtoastheterrestrialcorenetwork)butwiththepotentialforpartialdeploymentonsat-ellites(referredtoasthesatellitecorenetwork).ThisunifiednetworkarchitectureenablestheITSCsystemtoleverageintegratedradioaccess,transmission,andnetworktechnologies,alongwithsatellite-terrestrialcollaborativewirelessresourceallocationandservicemanagement.Theobjectiveistoprovidebroadbandornar-rowbandaccessservicestovariouscommunica-tiondevices,meetingthecommunicationneedsofspace-based,sea-based,andland-basedusersanytimeandanywhere[3][4].Additionally,ITSCfacilitatesthedeepintegrationofcommunica-

tionequipment,devices,services,andappli-cations,resultinginsignificantcostreductionandpromotingthepositivedevelopmentoftheentireindustry[4].

OnenotableapplicationofITSCisDS2MPC,whichnecessitatestheenhancementofbothterminalcapabilitiesandnetworkcoverage.DS2MPCrepresentsaredefinitionoftraditionalsatellitemobilecommunications,movingawayfromdedicatedterminalsthatprimarilyoffervoiceandlow-ratedataservices.Moreover,itservesasavitalmeasurefor6Gtorealizeon-de-mandaccessandseamlesscoverage.Therefore,thevisionofDS2MPCrevolvesaroundenablingterminalsthatareoriginallydesignedforter-restrialcommunicationtoaccesssatellitesandseamlesslyhandoverbetweenterrestrialAccessPoints(APs)andsatelliteAPs.Thisseamlessin-tegrationensuresglobalcoverageanduninter-ruptedservicesbecomeatangiblereality.

GEO

MEO/LEO

AA

near-spaceAPs

intelligentMANOterrestrialcellularAPs

Figure1-Athree-dimensionalITSCnetwork

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Keyperformanceindicatorsand

technicalchallenges

IntegratedTerrestrial-SatelliteCommunication(ITSC)

3.1Keyperformanceindicator(KPI)

TogaininsightsintothecapabilitiesofsatellitecommunicationinITSC,preliminaryestima-tionsofKPI[5~8]arederivedbyreferencingKPIsfromterrestrialcommunication,takingintoaccounttypicalsatelliteconstellations,fre-quencyresources,payloadconfigurations,andthedevelopmentofsatellitetechnologiesanddevices.

Peakdatarate

Thedownlinkpeakdatarateforsatellitebeamscanrangefrom10to50Mbpsforterminalswithlow-gainantennas(suchasmobilephonesandIoTterminals)andfrom50to1000Mbpsforterminalswithhigh-gainantennas(e.g.VerySmallApertureTerminal-VSAT).Witheachsatellitesupportingtenstohundredsofbeams,thecapacityofeachsatellitecanbesetat10to100Gbps.

Airinterfacedelay

Theairinterfacedelaytypicallyincludesprop-agationdelay(approximately1.1to11milli-secondsforLEOon-boardprocessingmodeandover100millisecondsforGEOsatellites),processingdelayfromtransmittersorreceiv-ers(generally1to2millisecondsatone-side),schedulingdelayfrombeam-hopping(limitedtowithin80millisecondsbysynchronizationtime),andretransmissiondelayfromHybridAutomaticRepeatreQuest(HARQ)(dependentonthenumberofretransmissions,propagationdelay,processingdelay,andschedulingdelay).Minimizingthenumberofretransmissionsor

avoidingtheretransmissionmechanismiscru-cialwhendealingwithsignificantpropagationorschedulingdelaysduringbeam-hoppingorreal-timeinteractiveservices.

Dopplershift

Dopplershift,rangingfromseveraltenstosev-eralhundredkHzindiferentfrequencyranges,isdeterminedbythesignalfrequencyandtherelativeradialvelocitybetweenthesatelliteandtheterminalorgatewaystation.Itcansignifi-cantlyimpactsynchronization,randomaccess,signaldetection,andotherprocesses.

Terminalspeed

Satellitecommunicationsupportsvarioustermi-naltypes,includingmobilephones,fixedtermi-nals,vehicularterminals,ship-bornevehicles,andairbornevehicles.Airbornevehicles,withspeedsreachingupto1000km/h,presentchal-lengesinschemedesignforsynchronization,mobilitymanagement,andconstraintsonbeamwidthandbeamsteering.

Spectralefficiency

Duetolimitedpowerbudgetandlowerlinearitycomparedtoterrestrialcommunication,satellitecommunicationtypicallyexhibitslowerSpectralEfficiency(SE).ThepeakSEforaterminalwithahigh-gainantennashouldexceed3bit/s/Hz.

Frequencyreuse

Unliketerrestrialcommunication,whichcom-monlyemploysco-frequencyreuse,satellite

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communicationrequiresseparatefrequenciesfortheservicelinkandfeederlink.Thefre-quencyreusefactorforsatellitecommunicationisgenerallysetat2to8,withalargerfactorindi-catingreducedinterferencefromadjacentbeams.

Linkavailability

Radiolinkavailabilityinsatellitecommunicationisinfluencedbyenvironmentalfactorssuchastheionosphere,atmosphere,cloudsandrain.Typi-cally,theavailabilityfortheservicelinkshouldnotfallbelow98%,whilethefeederlinkshouldmaintainatleast99%availability.Inpractice,linkavailabilitycanbecomprehensivelyconsid-eredbasedonfactorslikefrequency,coverage,customerclassandcost.Meanwhile,customers

signservicelevelagreementswithoperator.

Cellradius

Satellitebeamscorrespondtocellradiirangingfromtensofkilometerstooverathousandkilo-meters,resultingincoveragespanningtensofthousandsofsquarekilometers.Thisextendsbeyondthecoveragerangeofaterrestrialcell.

Numberofusersperbeam

Basedonuserdistributionintypicalscenariosanddesignobjectivesofexistingsatellitecom-municationsystems,futuresatellitecommuni-cationwillaimtosupportover5000activeuserspersatelliteandapproximately500activeusersperbeam.

3.2Technicalchallenges

Aseriesoftechnicalchallengeshavebeeniden-tifiedtomeettherequirementsofITSC,includ-ingunifieddesignforairinterface,beamdesigntobalancebeamcoverageandsystemcapacity,complexanddynamicinterferencemanagement,simplifiedprotocoldesign,diversifiedtermi-nals,anddynamichugespacebearernetwork.

Unifieddesignforairinterface

Designingaunifiedairinterfaceposessignifi-cantchallengesduetotheinherentdiferencesbetweensatelliteandterrestrialchannellinks.Factorssuchasorbit,frequency,andterminalantennatypecanaffectthesatellitechannel,whichtypicallyexhibitsastrongRician-type

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channel.However,multipatheffectsshouldbeconsideredforterminalsusingomnidirectionalorlow-gainantennas.Theterrestrialchannel,ontheotherhand,experiencesstrongmultipathfading,leadingtosignificantsignalvariationseveninadjacenttimeandlocation.Therefore,theairinterfacedesignforITSCmustaddressthevariabilityoftheseapplicationscenarios.

Beamdesigntobalancebeamcoverageandsystemcapacity

Thelimitedtransmittingpowerofsatellitesre-strictsthenumberoffixedbeamsthatcanbedeployed.Beam-hoppingisapotentialsolutionthatallowsdynamicadjustmentaccordingtoservicerequirements.Thenumberofbeamsaffectssystemcapacityandbeamcoverage.Asmallernumberofbeamsresultsinwiderbeamcoveragebutlowersystemcapacity,whilealargernumberofbeamsprovidesnarrowerbeamcoveragebutincreasesthehoppingtime.Therefore,beamdesignmuststrikeabalancebetweenbeamcoverageandsystemcapacity.

Complexanddynamicinterferencemanagement

InanITSCenvironmentwithfrequencyshar-ing,complexinterferencescenariosarisethatneedtobemitigated.TheseincludeinterferenceavoidancebetweenNon-GeostationaryOrbit-ing(NGSO)satellitesandGeostationaryEarthOrbit(GEO)satellites,interferenceavoidancebetweenterrestrialAPsandsatelliteAPs,andinterferenceavoidancefromsystemssuchasearthexplorationandmeteorologicalsatellites.Effectiveinterferencemanagementstrategies

areessentialtoensurereliablecommunicationinthepresenceoftheseinterferences.

Simplifiedprotocoldesign

Payloadcapacityandvolumelimitationsneces-sitatethesimplificationofon-boardprocessingprotocolsateachlayer.Thissimplificationaimstoreducethechallengesassociatedwithimple-mentingsoftwareandfirmware-basedspaceprotectionmeasures.Bysimplifyingprotocols,thedifficultiesinrealizingthesemeasurescanbemitigated.

Diversifiedterminals

FutureITSCsystemmustsupportmultipletypesofterminals,eachwithvaryingcapabil-itiesbasedondeploymentandusagescenar-ios.Thesedifferencescanincludeoperatingfrequencybands,bandwidth,peakdatarates,dynamicadaptability,servicetypes,andenergyconsumption.Thecommunicationprotocol,re-sourcescheduling,mobilitymanagement,andservicemanagementmustadapttotheneedsofthesediversifiedterminals,whichmayincreasethecomplexityofcommunicationpayload.

Dynamichugespacebearernetwork

TheadvancementoflasercommunicationhasledtotheprospectofInter-SatelliteLink(ISL)insatellitecommunication.Thisdevelopmentwillgiverisetoadynamictopology,formingavastspacebearernetwork.However,thecurrentdevice-levelelasticitymechanismisrelativelyweak,makingitchallengingtosatisfyQualityofService(QoS)requirementsinsatellitecommu-nication.

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3.3KPIsandtechnicalchallengesforDS2MPC

KeytechnicalindicatorsofDS2MPCarelistedasfollows:

Peakdaterate

ComparedtoVSAT,mobilephonesinDS2MPCoperateatlowerfrequenciesandexhibitlowertransmissionpowerandnarrowerbandwidth.Asaresult,thespectrumefficiencyandpeakdatarateofDS2MPCinITSCwillbesignificantlylowerthanthoseinterrestrialcommunication.

Bandwidth

DS2MPCsystemstypicallyoperateinlow-fre-quencybandssuchasL,S,orCbands,resultinginbandwidthsgenerallybelow20MHz.Thisisconsiderablylowerthanthebandwidthavaila-blein5GNewRadio(NR)ortraditionalsatellitecommunication.

Spectralefficiency

Thelimitedtransmittingpowerofmobilephonesrestrictsachievinghighsignal-to-noiseratio(SNR),leadingtoreducedspectrumeffi-ciency.Additionally,itischallengingtoutilizemultipleinputmultipleoutput(MIMO)technol-ogytoincreasethecapacityofasatellite.

Consequently,DS2MPCinITSCfacesspecificchallenges,includinglowSNRafectingdatarate,frequencycoordinationbetweensatelliteandterrestrialsystems,andmobilitymanagement.

LowSNRondatarate

TomitigatetheimpactofpoorreliabilityandlowdataratescausedbylowSNR,communi-

cationlinksneedtobeenhanced.Thiscanbeachievedbyincreasingtheantennagainfromsatellitesandimplementingrepetitiontransmis-siontechniques.

Frequencycoordinationbetweensatel-liteandground

Sharingthelow-frequencybandbetweenter-restrialandsatellitecommunicationpresentsdifficulties.Unifiedplanning,deployment,andmanagementbasedoninterferencecriteriaarenecessary.However,achievingconsensusamongallInternationalTelecommunicationUnion(ITU)participatingunitscanbechalleng-ing,potentiallyresultinginlimitedimplementa-tionoffrequencysharinginspecificareas.

Mobilitymanagement

Ascoverageandserviceareasexpand,newchal-lengesemerge,includingservicegeographicaldiferentiationandregulatoryconstraints.Accu-ratedeterminationofmobilephones’servicelocationsonthenetworksidebecomescrucial,enablingtheselectionoftheappropriatelegalCNtocomplywithlocallawsandregulations.

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RoadmapforITSC

IntegratedTerrestrial-SatelliteCommunication(ITSC)

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BasedonpreviousstudiesonNTNandpresentvisionon6G,ITSCisevolvingfromtherouteof“stand-ardcompatibilityin5G”towardtherouteof“systemintegrationin6G”.

4.1ITSC’sstandardcompatibilityin5G

Satellitecommunicationwasnotinitiallycon-sideredintheearlystagesof5GNRdevelop-ment.However,withevolvingtechnologyandrequirements,satellitecommunicationstudy,namelyasNTN,wasinitiatedduringtheR15laterstageat3GPP.ThefirstversionsupportingNTNnetworkswascompletedinR17basedontheoptimizationofterrestrial5GNR,including

timingrelationshipenhancement,timeandfrequencycompensation,HARQimprovementmechanismforlargeround-triptime,mobilitymanagementandhandoverenhancement.Sat-ellitecommunication,benefitingfromthecom-patibilitywithterrestrial5G,canleveragetheadvantagesofsharingtheindustrialchainandscaleeconomiesofterrestrial5G.

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4.2ITSC’ssystemintegrationin6G

Inthe6Gera,differenttypesofaccessmodesfromterrestrialorsatellitehavebeenfullyconsideredatthebeginningoftheformulationofthestandard.Itisnecessaryforterrestrialmobilecommunicationtoorganicallyintegratewithvarioussatellitestypescoveringhigh,me-diumandloworbits,enablingseamlessglobal

coverageandubiquitousnetworkaccess.TheITSCin6Gistheintegrationofmultiplehet-erogeneousaccessnetworks,characterizedbymulti-layer,three-dimensional,dynamicandtime-varying.Allchallengeswillbethoroughlyanalyzedandsolvedfromtheinitialstageof6Gdesigntorealizethecompleteintegration.

4.3DS2MPCwillbethekeymilestoneapplicationofITSC

IncurrentRel-18stage,3GPPisactivelywork-ingonfurtherlinkenhancementtosupportDS-2MPC.ItisexpectedthatDS2MPCwillgarnermoreattentionin6G,enablingmobilephone

userstoswitchsmoothlybetweenterrestrialAPsandsatelliteAPswithoutawarenessofser-viceinterruption.

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KeytechnologiesofITSC

system

IntegratedTerrestrial-SatelliteCommunication(ITSC)

TomeetthetechnicalchallengesofITSC,severalkeytechnologiesneedtobestudied,includingnet-workarchitecture,wirelesstransmissiontechnology,mobilitymanagementtechnology,networkandsecuritytechnology,satellite-terrestrialspectrumsharingtechnology,andengineeringimplementa-tiontechnology.

5.1Networkarchitecture

RAN

BN

Figure2illustratesthenetworkarchitectureoftheITSCsystem,whichenablesmultipleaccessmodesforterrestrialbasestationsorsatellites[8-10].TheintegrationofOn-BoardProcessing(OBP)andISLplaysacrucialroleinsimplifyingthedeploymentofgatewaystations.Addition-ally,consideringtechnicalconstraints,launchcapabilities,costs,andspecificrequirements,

NF2

NF3

NF4

NF1

SimplifiedCloudPlatform

theTransparentProcessing(TP)modepresentsaviablealternative.Therefore,thefutureITSCsystemshouldsupportvariousnetworkarchi-tecturetypes,includingtheRANsharingnet-workingmodewithMulti-OperatorCoreNet-work(MOCN),aswellasthehybridnetworkingmodeencompassingTN,NTN-OBP,andNTN-TP.

IntelligentMANO

GEO

NetworkSensingFunction

RAN

NF

BN

SpaceBearer

Network

LightCloudPlatform

NF1NF2NF3

SimplifiedCloudPlatform

LEO-OBP

LEO-OBP

Transponder

LEO-TP

On-boardBS

Rounter

Lasersystem

LEO-OBP

VNFVNFVNF

CloudOS

ComputingEquipments

Storage

Equipments

ExchangeEquipments

CoreNetwork

NF6NF5NF4NF3NF2NF1

GW-Feeder

GW-BS

Nnf6Nnf5Nnf4Nnf3Nnf2Nnf1

Nnf7