2024 全球6G技术大会 -10.0M Massive Access Technology

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Abstract

Massiveaccesstechnologyreferstothetechnologiesdevelopedtoaddressthechallengeofaccommodatingextensiveconnectivity.6Gsetshigherdemandsforconnectiondensity,specificallytargetingscenarioswithmassiveconnections.Theenvisionedconnectiondensityfor6Gistensofmillionsofterminalspersquarekilometer.6GcanbringaboutafullydigitalsocietybyintegratingInternetofEverything(IoE),allowingindividualstoengageinnatural,inspiring,andpervasiveinteractionswiththeirsurroundings.Eachindividualisanticipatedtoactivatetenstohundredsofterminalsconnectedtothe6Gnetwork,withtheinteractioncycleformachine-typeterminalsexpectedtodecreasefrom1dayor2hoursin5Gtomereseconds.Inthecontextof6G,thereareincreaseddemandsforlowlatency,particularlyforthesporadictransmissionofsmallpacketsbymachine-typeterminals.ThisnecessitatesafurtherreductioninthedelayfrominitialaccesstoestablishingaRadioResourceControl(RRC)connection,

aimingtoachievesimplifiedaccessprocedures.

6GadvancestheMassiveMachineTypeCommunications(mMTC)scenariobyintroducingtheMassiveCommunicationscenario,whichinvolvesapotentiallyenormousnumberofaccessterminals,reachinguptotensofmillionspersquarekilometer.Additionally,inthecontextof6G,theImmersiveCommunicationandHyperReliableandLow-LatencyCommunication(HRLLC)scenariosstemmingfromEnhancedMobileBroadband(eMBB)andUltra-ReliableLow-LatencyCommunications(URLLC)scenariosbringforthincreaseddemandsforindicatorssuchasconnectiondensityandlatency.Tosatisfythesedemands,

extensiveresearchintomassiveaccesstechnologyisessential.

Thiswhitepaperaimstolayouttheframeworkofmassiveaccesstechnology,investigateitsapplicationscenariosanddemands,pinpointandillustratethetechnicalproblemsthatneedtobefixed,offerapathforwardtosolvetheseproblems,andsuggestspecifictechnicalfixes.Firstly,itexaminesthemanyapplicationsofmassiveaccesstechnologyandoutlinestherequirementsforindicatorslikeconnectiondensity,latency,datatransmissionfrequency,anddatapacketsizeineachapplication.Itthenexaminesthe

requirementsformassiveaccesstechnology,includingenhancingconnectiondensity,

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decreasingcommunicationlatency,andoptimizingcommunicationprocesses,inconjunctionwiththeparticularrequirementsofusecases.Itthenturnstostudythekeytechnologiesforenablingmassiveaccess,explorestheindustry'sprevailingtechnicalapproachofUnsourcedMultipleAccess(UMA),andsuggestsUncoordinatedRandomAccessandTransmission(URAT)technology,efficientconnectionlesstransmissiontechnology,sparseInterleaveDivisionMultipleAccess(IDMA)forUMA,andmulti-userencodinganddecodingschemesbasedonOn-OffDivisionMultipleAccess(ODMA).Basedonthis,itrefinesthedesignschemesfortransmittersandreceiversandpresentsresourcehopping,patterndivisionrandomaccess(PDRA),andVirtualUserSplittingasthefoundationformultipleaccessschemes;iterativereceiversbasedonSparsificationTransformation;capacity-optimizedandlow-complexityiterativereceivers;andmulti-userencodingschemes.Finally,itintegratesandcategorizestheproposedkeytechnologies,refiningthemtocreateatechnicalroadmap

forenablingmassiveaccess.

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Contents

1.Introduction(CICTMobile)

4

2.ApplicationScenariosofMassiveAccessTechnology(CICTMobile,ChinaUnicom)

7

3.ImportantUseCases

1

0

3.1ToCDigitalTwinWorld(CICTMobile)

1

0

3.2CriticalConnection-IntensiveIoV(ZTE,CICTMobile)

1

2

3.3Ultra-Low-PowerIoT(vivo)

1

4

4.BasicRequirements(CICTMobile)

1

7

5.CommunicationProcessofMassiveConnections(CICTMobile,vivo)

1

9

6.KeyTechnologiesforEnablingMassiveAccess

2

4

6.1UMASchemes

2

5

6.1.1URAT(CICTMobile)

2

5

6.1.2EfficientConnectionlessTransmission(ZTE)

2

7

6.1.3Multi-UserEncodingandDecodingSchemesBasedonODMA(XDU)

4

2

6.1.4SparseIDMAforUMA(ChinaMobile)

4

5

6.2TransmitterDesignSchemes

5

1

6.2.1MultipleAccessSchemeBasedonVirtualUserSplitting(DOCOMO)

5

1

6.2.2MultipleAccessSchemeBasedonResourceHopping(BJTU)

5

5

6.2.3PDRA(USTB)

5

9

6.3ReceiverDesignSchemes

6

2

6.3.1IterativeReceiverBasedonSparsificationTransformation(USTB)

6

2

6.3.2Capacity-OptimizedandLow-ComplexityIterativeReceiverandMulti-UserEncoding

Scheme(XDU,ZJU)

6

6

7.TechnicalRoadmap(CICTMobile)

7

2

8.ConclusionandOutlook(CICTMobile)

7

7

References

7

9

ContributingUnit

8

2

AbbreviationsandAcronyms

8

3

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1.Introduction(CICTMobile)

AsemergingtechnologieslikeIoTandAIrapidlyadvance,thedemandforcommunicationtechnologiesisalsoontherise.Thearrivalof5Gtechnologyhasgivenpeopleaccesstofaster,morestable,andmorereliablecommunicationservices.However,asthenumberofIoTdevicescontinuestorise,accommodatingthemassiveinfluxofdeviceshasemergedasapivotalchallengeintoday'scommunicationlandscape.Traditionalcommunicationtechnologiesarenolongercapableofmeetingtheaccessdemandsimposedbythisvastvolumeofdevices.Therefore,investigatinganddevelopingmassiveaccesstechnologyhasemergedasacrucialfocalpointintheeraof6G.

Presently,numerousstandardizationorganizationsareactivelyengagedin6Gresearchandhavemadesubstantialadvancementsinnovelmultipleaccesstechnologies.Forexample,ITUhasexaminedanapplication-orienteddynamicaccessschemethat,withinanoverarchingframework,employsdiversemultipleaccessschemestailoredtospecificapplicationscenarios.Thisfacilitatesthepotentialconvergenceofdifferentmultipleaccessschemesandsupportsthestandardizedadvancementofnewmultipleaccesstechnologies.TheIMT2030(6G)PromotionGrouphasreachedaconsensusontechnicalconcepts,researchprogress,challenges,andresearchdirections.Thescopeofresearchencompassesfundamentaltransmissionmethodsatthetransmittingendandthesignalprocessingprocessatthereceivingend,providingaguidingframeworkforfutureresearchonnewmultipleaccesstechnologies.Thisfacilitatestheresolutionofoutstandingissuesandtheattainmentofsignificantbreakthroughs.InNovember2022,acrucialtechnicalresearchreportwasissued,introducingthepotentialofmassiveaccesstechnologywithoutuseridentificationbasedonNon-OrthogonalMultipleAccess(NOMA)togreatlyenhanceterminalconnectiondensity.Thisadvancementoffersrobustsupportfor6Gscenariossuchaslowpowerconsumptionandultra-large-scaleconnectivityandservesasthegroundworkforthoroughexplorationintophysicallayerairinterfacetechnology.FuTUREForumissuedtheWhitePaperon6GVisionandTechnologyTrends[1]in2020andtheWhitePaperontheEvolvedRandomAccessandMultipleAccessTransmissionTechnologies[2]in2022.Thesedocumentscovergrant-freetechnology,whichdoesnotnecessitatefullnetworkcoordination,andalsointroduceadesignapproachforintegratingrandomaccessandmultipleaccesstransmissiontechnologies.Inlarge-scaleconnectionscenarios,6GFlagshipemphasizesthesignificanceofNOMAasakeytechnology.Ithighlightstheneedtoaddresschallengesassociatedwithuseractivitydetectionanddatadecoding,whilealsoproposingresearchonNOMAtechnologythatoperateswithoutthenecessityforfullcoordination.

Meanwhile,therehavebeensignificantadvancementsintheacademicfieldofNOMAtechnology,leadingtotheintroductionofmassiveaccesstechnology[3].Allterminalsencodeinformationsequencesusingthesamecodebook,andthecodedbitsarethentransmittedoversharedresourcesusingSlottedALOHAaftermodulation.ItsprimarycharacteristicisthelackofnecessitytoallocateterminalIDsfortransmission,leadingtoitsdesignationasunsourcedoruncoordinatedmultipleaccess,whichhasemergedasaprominentresearchfocusinacademiccircles.Recently,academicresearchhasextensivelyexplorednovelmultipleaccesstechnologiesfor6G.ThereisawidespreadconsensusthatmMTCrepresentsapivotal

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scenariofor6G,requiringenhancedperformanceindicatorsbeyondthoseof5G.Consequently,theintroductionofinnovativemultipleaccesstechnologiesbecomesessentialtotackletheensuingchallenges.Intacklingsignificantchallengessuchaspilot/preambledesign,channelestimation,andmulti-useractivitydetection,manystudieshaveincorporatedtechnologieslikecompressedsensing,multi-userencoding,anddeeplearningtoproposesolutionssuchasUnsourcedRandomAccess(URA)andUMA.ThecoreconceptofURAliesinitsabilitytoenableconcurrentaccessanddatatransmissionwithoutrequiringcoordinatedschedulingoraseparateaccessprocess,thussimplifyingtheaccessprotocolandreducingsignalingoverhead.Widelyrecognizedastheprevailingmultipleaccessschemein6Gacademicresearch,itformsthebasisforthemajorityofmultipleaccessinvestigations.TheURAschemecurrentlyproposedinacademiccirclescanbeprimarilycategorizedintotwotypes.Onetypeinvolvestheuseofconcatenatedinnerandoutercodestotransmitpilotsanddataconcurrently,therebyintegratingtheaccessanddatatransmissionprocesses.Theothertypeemphasizesreducingthecouplingbetweeninnerandoutercodes.Theconcatenationofinnerandoutercodesoftennecessitatesadditionalredundantinformation,leadingtoadecreaseinspectralefficiency.Therefore,thisschemeprimarilyreliesonspecificcorrelatedinformation,suchasspatialandchannelcorrelations,toeliminateconnectioncoding.

Thiswhitepaperaimstoexploretheresearchanddevelopmentofmassiveaccesstechnologyinthe6Gera.Itseekstoestablishacomprehensiveframeworkforthistechnology,encompassingapplicationscenarios,technicalrequirements,keychallenges,viabletechnicalroadmaps,andseveralpivotaltechnologies.Ultimately,itaimstoprovidestrongsupportfortheadvancementof6Gtechnology.Chapter2outlinesthetwoprimaryapplicationscenariosofmassiveaccesstechnology,tailoredtovaryingtrafficmodelandperformanceindicators.Chapter3detailstheimportantusecasesofmassiveaccesstechnologyin6G,includingtheToCdigitaltwinworld,thecriticalconnection-intensiveIoV(InternetofVehicles),andultra-low-powerIoT(InternetofThings).Chapter4analyzestherequirementsformassiveaccesstechnologyin6Gbasedonscenariousecases,focusingonindicatorslikeconnectiondensity,latency,andterminaldatatransmissionfrequency,andaimingtoreducelatencybysimplifyingcommunicationprocessesandenhancingconnectiondensitythroughoptimizedtechnicalsolutions.Chapter5outlinesthecommunicationprocessformassiveconnections,encompassingsimplifiedsecurityandtransmissionmechanisms.Chapter6thoroughlyexaminestheprimarychallengesandexploreskeytechnologiestofulfillthesedemands.TheseencompassURAT,efficientconnectionlesstransmissiontechnology,multi-userencodinganddecodingschemesbasedonODMA,sparseIDMAforUMA,multipleaccessschemesbasedonresourcehoppingandVirtualUserSplitting,PDRA,iterativereceiversbasedonSparsificationTransformation,capacity-optimizedandlow-complexityiterativereceivers,andmulti-userencodingschemes.Chapter7offersaforward-lookingperspectiveontechnologicalevolutiontoshapetheroadmapforfuturemassiveaccesstechnology.Thisencompassesnon-orthogonal,uncoordinated,integratedrandomaccessandmultipleaccesstransmission,andconsiderationsforreceiverdesign.Chapter8concludesandprovidesafutureoutlook.

Thiswhitepaperholdsvitalsignificanceindrivingtheresearchanddevelopmentofmassiveaccesstechnologyintheeraof6G.Firstly,thiswhitepaperintroducesthe

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fundamentalframeworkanduniversalrequirementsofmassiveaccesstechnology,offeringguidanceandreferenceforfutureresearch.Next,thiswhitepaperprovidesadetailedoverviewofthekeytechnicalsolutionsformassiveaccesstechnology,offeringinsightsandguidanceforresearchinrelevantfields.Finally,thiswhitepaperextensivelydeliberatesonthedemandchallengesandtheircorrespondingtechnicalroadmaps,establishingaconsensusandgroundworkforfutureendeavors.Webelievethat,throughcollectiveendeavors,massiveaccesstechnologywillprogressandcontributesignificantlytotheIoTandassociatedfields,establishingthegroundworkforanadvancedintelligentsocietyanddeliveringincreasedconvenienceandinnovationtopeople'slives.

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2.ApplicationScenariosofMassiveAccessTechnology(CICT

Mobile,ChinaUnicom)

6Gisexpectedtodemonstrateanotablysubstantialincreaseinconnectiondensitycomparedto4Gand5G.While4Gboastsaconnectiondensityof2,000connectionspersquarekilometerand5Greachesonemillionconnectionspersquarekilometer,theprevailingindustryexpectationisthat6Gwillachieveastaggeringtenmillionconnectionspersquarekilometerorpossiblyevenhigher.Inmassiveconnectionscenarios,adiverserangeofterminaldevicetypesisanticipated.AlongsidetraditionalIoTdevices,theintroductionofnovelunsourced,low-powerterminaldevicesisexpected.

InJune2023,theITUfinalizedaproposal[4]outliningtheframeworkandoverallgoalsforIMT's2030andfuturedevelopment,andintroducedsixprimaryapplicationscenariosfor6G.Ontheonehand,itevolvedtheeMBB,mMTC,andURLLCscenarioswithin5G,presentingImmersiveCommunication,MassiveCommunication,andHRLLCscenarios.Ontheotherhand,itexpandedupontheexisting5GscenariostoproposeUbiquitousConnectivity,IntegratedArtificialIntelligenceandCommunication,andIntegratedSensingandCommunicationscenarios.

MassiveCommunicationscenariosencompassawiderangeofapplications,suchassmartcities,transportation,logistics,healthcare,energy,environmentalmonitoring,agriculture,andmanyotherfields.Theseapplicationsfrequentlyrequiresupportforavarietyofbattery-freeorlong-life-batteryIoTdevices.Highconnectiondensityisrequiredforsuchscenarios,andthedocumentproposesadensityrequirementrangingfrom106to108devicespersquarekilometer.Additionally,tailoredtospecificusecases,thereisarequirementtoaccommodatevaryingdatarates,powerconsumption,mobility,andcoveragerange,aswellasconsiderationsforsecurityandreliability.

Inexistingtechnology,terminalsmustestablishnetworkaccessbeforeinitiatingdatatransmission.Thenumberofterminalsthatcanbesupportedislimitedbydatatransmissionresourcesandcoordinatedsignalingresourcesofthenetwork.ForMassiveCommunicationin6G,connectiondensityisrequiredatamuchhigherlevelthanin5G,possibly100timeshigher.Comparedto5G,6Gscenarioswillsupportawiderrangeoftypicalusecasesandterminaldevicetypes,placingadditionaldemandsonthetrafficmodel.Forexample,therewillbeanincreaseintheterminaldatatransmissionfrequency.Onemessageperdeviceeverytwohoursistherecommendedterminaldatatransmissionfrequencyunderthe5GmMTCtrafficmodel[5].AccordingtotheIMT-2030(6G)PromotionGroup,terminaldatatransmissionfrequencyinultra-large-scaleconnectionscenariosmightbeaslowasonceadayorashighasonceeveryfewmilliseconds[6].Thereisagreaterneedforconcurrentuseraccesswithinaparticularperiodoftimeduetotheincreaseinterminalquantityanddatatransmissionfrequency.Itisexpectedtosupportsimultaneousaccessofhundredsofterminalspermillisecond.Thechallengethatneedstobeovercomeissupportingcommunicationformassiveterminalswhilestayingwithinthelimitsofnetworksignalinganddatatransmissionresources.Therefore,itisessentialtoexploremassiveaccesstechnologytoaccommodatea

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greaternumberofterminalconnections.

MassiveCommunicationscenariosputforwardhigherrequirementsforconnectiondensity,whiletherequirementforlowlatencyisusuallylessstrictandcanoftentoleraterelativelyhighlatency,enablingend-to-endcommunicationtobeachievedwithinmereseconds.Inpracticalapplications,itisimportanttoconsidernotonlythenumberofsupportedterminals,butalsothedatapacketsize,end-to-endcommunicationlatency,andthereliabilityofdatatransmission.Insomecases,therequiredconnectiondensityislessthanthatofMassiveCommunicationscenarios,whichcallfor108devicespersquarekilometer.Itissufficienttohaveabout106devicespersquarekilometer.However,applicationssuchasIoVandsmartfactoriesrequiremillisecond-levelend-to-endcommunicationlatency.Furthermore,insomeapplicationscenariossuchasdigitaltwins,largerdatapacketsizesarerequired.Examplesoftheseincludethetransferofpacketsofhundredstothousandsofbytes.Onthebasisofmeetinghigherlatencyrequirementsandlargertransmissionpackets,furthersupportingtheaccessofmassiveterminalsfacessignificantchallenges.Therefore,thereisanimperativeneedtoconductresearchonmassiveaccesstechnologycapableofmeetinghighlatencyrequirementsandfacilitatinglargerdatapackettransmissions.

Accordingtodifferenttrafficmodelandindicatorrequirements,theapplicationscenariosofmassiveaccesstechnologycanbedividedintotwocategories:onetypeisMassiveCommunication,whichrequiressupportforalargenumberofterminals(e.g.,108devices/km2),isnotsensitivetolatency,usuallytransmitsburstysmalldatapackets,andhashighdemandsforconnectiondensitybutlowrequirementsfordatatransmissionfrequency,latency,datapacketsize,andreliability,asindicatedbytheorangecurveinFigure2-1.Theothertypeisthescenariothatsupportsalargenumberofterminals(e.g.,106devices/km2)whileplacinghigherdemandsonthesizeoftransmitteddatapackets,end-to-endcommunicationlatency,anddatatransmissionreliability.ThisscenariointegratesthecharacteristicsofMassiveCommunication,ImmersiveCommunication,andHRLLCscenarios,representingacombinationofthesethreescenarios,withitskeyindicatorcapabilitiesshownbythebluecurveinFigure2-1.Ithaslowerrequirementsforconnectiondensitycomparedtothefirsttypeofapplicationscenario,buthigherrequirementsfordatatransmissionfrequency,latency,datapacketsize,andreliability.

Figure2-1ApplicationScenariosofMassiveAccessTechnology

Massiveaccesstechnologyenablestheconnectionofmassiveterminals,meetingthe

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demandsofthementionedscenarios.Ontheonehand,itcansatisfythe6Grequirementsforlatency,connectiondensity,andotherindicators.Ontheotherhand,inusecaseslikedigitaltwinsandultra-low-powerIoTthatnecessitatethedeploymentofmassivedevices,massiveaccesstechnologycanbeemployedasanunderlyingtechnologytosupportterminalaccessanddatatransmission.

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3.ImportantUseCases

3.1ToCDigitalTwinWorld(CICTMobile)

Byintegratingsensing,computing,modeling,simulation,andcommunicationtechnologies,digitaltwinenablesreal-timeinteractionandseamlessconnectionbetweenthephysicalanddigitalworlds.Itsextensiveapplicationsspanacrossintelligentmanufacturing,smartcities,smartagriculture,andhealthcare[7].Digitaltwinpresentsmanychallengesforthearchitectureandcapabilitiesof6Gnetworks,demandingsubstantialdeviceconnections,highthroughput,low-latencytransmission,andmore.Thisisessentialfortheprecisereal-timecaptureofsubtlechangesinthephysicalworldandthetransmissionofinteractioninformation.Forexample,thefollowingtechnicalspecificationsmustbemet:connectiondensityof107–108devicespersquarekilometer,airinterfacelatencyoflessthan1ms,transmissionratesrangingfromMbpstoGbps,anderrorprobabilityoflessthan10-5[6].

Digitaltwiniswidelyusedonboththeconsumerside(C-end)andindustrialside(B-end),stimulatingcreativeactivitiesandcommunicationinthevirtualworld,whileenhancingindividuals'understandingofthelawsgoverningthephysicalworld.TheToCdigitaltwinworldexpandsuponthephysicalanddigitalworldsbyintroducingahuman-centricdimensionencompassingsensoryperception,physicality,intellect,andvalues.Thisintegrationfacilitatesinteractiveinformationexchangeamongthesethreeworlds,withafocusondeliveringpersonalized,real-time,andimmersiveexperiencesforindividuals.Itischaracterizedbyall-inclusiveconnectivity,real-timequality,andaccuracy.

Figure3-1ToCDigitalTwinWorld

Using"ImmersiveTouroftheForbiddenCity"asanexample,thefollowingillustratesthetypicalfeaturesoftheToCdigitaltwinworld:

.Personalizedexperience:ByconstructingaToCdigitaltwinworldoftheForbiddenCity,thevirtualscenerymaybeadjustedtovisitors'owntastes,improvingtheviewingexperience.Toprovidevisitorswithpersonalizedexperiences,itneedsa

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highconnectiondensity—106devices/km2.

.Realtimeexperience:Thevirtualscenerymustseamlesslyintegratewiththearchitectureandculturalrelics,providingreal-timepresentationtovisitorsforaseamlessfusionofthevirtualandthephysical.Thisrequiresstringentlatencytoachievemillisecond-levelend-to-endcommunication.

.Immersiveexperience:Likethemixedreality(MR)effect,thistechniquerestoresanddisplaysthepalace'sgrandeur,coloraesthetics,historicalrelevance,andotherelementsbysuperimposinggenuinebuildingsandculturalrelicsontovirtualscenery.Thisprovidesvisitorswithanincrediblyimmersiveexperience.Toproduceacompletelyimmersiveexperience,hundredstothousandsofbytesofdatapacketsmustbetransferred.

Comparedto5G,6Ghassignificantdifferencesandhigherrequirementsintermsofimmersiveexperience.6Gwillprovidehigherperformanceintransmissionspeed,networklatency,connectiondensity,andreliability.

•Transmissionspeed:While5Gaimsforatransmissionspeedof20Gbps,6Gisprojectedtoreach1Tbps,whichwillmaketheimmersiveexperiencesmootherandmorerealistic.

•Networklatency:6Gisexpectedtoachieveultra-lowlatencyaslowas1ms.Comparedtothelatencyof1-10msin5G,itwillgreatlyimprovetheperformanceofreal-timeinteractioninimmersiveexperiencesandreducetheimpactoflatencyonuserexperience.

•Connectiondensity:Theconnectiondensitysupportedby5Gis1millionconnectionspersquarekilometer,and6Gisexpectedtosupport10millionconnectionspersquarekilometer.Thismeansthat6Gwillbeabletoprovidehigherqualityimmersiveexperiencesinhighconnectiondensityscenarios.

•Reliability:Tomeettherequirementsofimmersiveexperiences,6Gisprojectedtomakesignificantadvancementsinreliability.Forexample,itaimstoprovide99.9999%servicereliabilityforcriticaltasksandreal-timeinteractiveapplications.

Table3-1illustratestheestimatedtrafficmodelforthisusecase,includingtheterminaldevicetype,terminaldevicequantity,andstatusreportingfrequency.

Table3-1TrafficmodelforImmersiveTouroftheForbiddenCity

TerminalDevice

Type

TerminalDeviceQuantity

Status

ReportingFrequency

Terminal

Quantity

perSecond

EstimationBasis

Tourists'smartdevices

104~105

About1/min

103~104

NumberofvisitorstotheForbiddenCity

Buildingprotection

sensor

104~105

About1/min

103~104

UsecasesinTR22.840

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Culturalrelicdisplaysensor

104~105

About1/min

103~104

NumberofculturalrelicsondisplayintheForbidden

City

Realenvironment

sensingand

imagingdevices

103~104

About1/s

103~104

AreaoftheForbiddenCity

Culturalrelic

storagesensor

105~106

About1/hour

103~104

UsecasesinTR22.011

Total(numberofterminalsaccessedand

transmittedpersecond)

104~105

Approximateestimationresults

TheToCdigitaltwinworldprioritizesthehumanexperience.Itaimstodeliverpersonalized,real-time,andimmersiveexperiencestailoredtouserneedsbysupportingmassivedevicecommunication.ComparedtotheMassiveCommunicationscenario,higherrequirementsareplacedondatatransmissionlatencyandpacketsize.Thisentailssupportingaconnectiondensityofapproximately106devices/km2,facilitatingcommunicationfromhundredsofterminalspermillisecond,andensuringmillisecond-levelend-to-endlatency.Additionally,acrossvarioususecases,thepacketsizesvaryfromhundredstothousandsofbytes.Theexistingmethodofestablishingaconnectionbeforedatatransferleadstosubstantialtransmissionlatency,impactinguserexperiencewithintheToCdigitaltwinworld.Therefore,itisnecessarytoexploremassiveaccesstechnology,simplifythesignalinginteractionfrominitialaccesstomultipleaccesstransmission,andreducelatency.

3.2CriticalConnection-IntensiveIoV(ZTE,CICTMobile)

High-densityIoVinformationtransmissionexhibitsbothmassivenessandburstiness,thusnecessitatinglowlatencyandhighreliability.Meetingtherequirementsforlowlatencyandhighreliabilityinscenariosofmassiveandburstyinformationtransmissionposesaconsiderablechallenge.Moreover,therapidmovementofvehiclenodesresultsinswiftchangesinthenetworktopologyoftheIoV,makingitevenmorechallengingtosimultaneouslymeettherequiremen