關(guān)于多供應(yīng)商部署的頻譜聚合 O-RAN.WG1.TR.SA-MVD-R004-v03.00

DOCPROPERTY"Documentnumber"

O-RAN.WG1.TR.SA-MVD-R004-v03.00

TechnicalReport

O-RANWorkGroup1(UseCasesandOverallArchitecture)

DOCPROPERTYTITLE

SpectrumAggregationforMulti-VendorDeployments

Copyright?2024bytheO-RANALLIANCEe.V.

ThecopyingorincorporationintoanyotherworkofpartorallofthematerialavailableinthisdocumentinanyformwithoutthepriorwrittenpermissionofO-RANALLIANCEe.V.isprohibited,savethatyoumayprintordownloadextractsofthematerialofthisdocumentforyourpersonaluse,orcopythematerialofthisdocumentforthepurposeofsendingtoindividualthirdpartiesfortheirinformationprovidedthatyouacknowledgeO-RANALLIANCEasthesourceofthematerialandthatyouinformthethirdpartythattheseconditionsapplytothemandthattheymustcomplywiththem.

O-RANALLIANCEe.V.,BuschkaulerWeg27,53347Alfter,Germany

RegisterofAssociations,BonnVR11238,VATIDDE321720189

STYLEREFZA

O-RAN.WG1.TR.SA-MVD-R004-v03.00

________________________________________________________________________________________________?2024bytheO-RANALLIANCEe.V.Youruseissubjecttothecopyrightstatementonthecoverpageofthisspecification.

Contents

TOC\o"1-3"

Foreword

4

Modalverbsterminology

4

Executivesummary

4

1 Scope

5

2 References

5

2.1 Normativereferences

5

2.2 Informativereferences

5

3 Definitionofterms,symbolsandabbreviations

6

3.1 Terms

6

3.2 Symbols

6

3.3 Abbreviations

6

4 Objectivesandrequirements

7

4.1 Currentchallengesforspectrumaggregationinmulti-vendorRAN

7

4.2 Objectives

7

5 Scenariosandconsiderations

8

5.1 Overview

8

5.2 Deploymentscenarios

9

5.2.1 Co-locateddeployments

9

5.2.2 Non-co-locateddeployments

10

5.2.3 Transportassumptions

12

5.3 Considerationsforspectrumaggregationtechniques

12

5.3.1 UEconsiderationsfromnetworkperspective

12

5.3.2 Spectrumconsiderations

13

5.3.3 Synchronizationconsiderations

16

5.3.4 Networkmanagementconsiderations

16

5.3.5 RANintelligenceconsiderations

17

5.3.6 Considerationsforsolutionevaluation

17

6 Spectrumaggregationsolutions

18

6.1 Overview

18

6.2 Solution1:IntraO-DUCarrierAggregation

19

6.2.1 Solutiondescription

19

6.2.2 Mappingtodeploymentscenariosandotherconsideration

21

6.2.3 Impactanalysisonspecifications

21

6.2.4 Feasibilityandgain/complexityanalysis

21

6.3 Solution2:InterO-DUCarrierAggregation

22

6.3.1 Solutiondescription

22

6.3.2 Mappingtodeploymentscenariosandotherconsideration

27

6.3.3 Impactanalysisonspecifications

28

6.3.4 Feasibilityandgain/complexityanalysis

28

6.4 Solution3:DualConnectivity

30

6.4.1 Solutiondescription

30

6.4.2 Mappingtodeploymentscenariosandotherconsideration

31

6.4.3 Impactanalysisonspecifications

32

6.4.4 Feasibilityandgain/complexityanalysis

32

7 Conclusionsandrecommendations

32

7.1 Summaryofevaluation

32

7.2 Impactonstandardization

36

7.3 Recommendations

36

AnnexA:Xhauldelayconsiderations

37

AnnexB:Examplesofmulti-vendorInterO-DUinterface

39

B.1 DLCAusinganInterO-DUinterface

39

B.2 High-leveldescriptionofInterO-DUinterface(D2)

39

AnnexC:Spectrumaggregationsolutiondecisiontreeanalysis

42

Annex:Changehistory/Changerequest(history)

44

Foreword

ThisTechnicalReport(TR)hasbeenproducedbyO-RANAlliance.

Modalverbsterminology

Inthepresentdocument"shall","shallnot","should","shouldnot","may","neednot","will","willnot","can"and"cannot"aretobeinterpretedasdescribedinclause3.2oftheO-RANDraftingRules(Verbalformsfortheexpressionofprovisions).

"must"and"mustnot"areNOTallowedinO-RANdeliverablesexceptwhenusedindirectcitation.

Executivesummary

Spectrumaggregationacrossdifferentbandsplaysanessentialroleforenhancinguserexperienceandefficientuseoffrequencyresources.AsMNOsgetaccesstonewNRspectrum,theyusuallydesiretoaggregatethecapacityacrossthedifferentbands.Thepresentdocumentaimstoidentifypracticalscenariosforspectrumaggregationacrossequipmentfrommultiplenetworkequipmentvendors.Thespectrumaggregationscenarioscoveravarietyofdeploymentcases.ThepresentdocumentconsidersscenarioswheredifferentO-RANNFscanbeco-locatedornon-co-located.SupplementaryspectrumaggregationscenariossuchasSUL,SDLdeploymentarealsocovered.Differentconsiderationsforspectrumcombinations,UErequirementsandsolutionevaluationcriteriaarealsodocumented.

Toaddressspectrumaggregationinmulti-vendorRANdeploymentscenarios,threesolutionsaredescribed:IntraO-DUCA,InterO-DUCA,andDualConnectivity.Thesolutionsaremappedtodifferentdeploymentscenariosandanalyzedbasedontheevaluationcriteria.WhiletheIntraO-DUCAandDualConnectivityscenariosarecoveredinexistingO-RANand3GPPspecifications,thepresentdocumentalsocoverstherequirementsforsupportinganewlyproposedInterO-DUCAsolutionalongwithabriefoutlineforthesolutionarchitecture.

1 Scope

ThecontentsofthepresentdocumentaresubjecttocontinuingworkwithinO-RANandmaychangefollowingformalO-RANapproval.ShouldtheO-RANAlliancemodifythecontentsofthepresentdocument,itwillbere-releasedbyO-RANwithanidentifyingchangeofversiondateandanincreaseinversionnumberasfollows:

versionxx.yy.zz

where:

xx: thefirstdigit-groupisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.(theinitialapproveddocumentwillhavexx=01).Always2digitswithleadingzeroifneeded.

yy: theseconddigit-groupisincrementedwheneditorialonlychangeshavebeenincorporatedinthedocument.Always2digitswithleadingzeroifneeded.

zz: thethirddigit-groupincludedonlyinworkingversionsofthedocumentindicatingincrementalchangesduringtheeditingprocess.Externalversionsneverincludethethirddigit-group.Always2digitswithleadingzeroifneeded.

Thepresentdocumentdescribesdifferentdeploymentscenariosthatcanbenefitfromspectrumaggregationinamulti-vendornetworkdeployment.Varioussolutionsforspectrumaggregationarealsostudied.

2 References

2.1 Normativereferences

Notapplicable.

2.2 Informativereferences

Referencesareeitherspecific(identifiedbydateofpublicationand/oreditionnumberorversionnumber)ornonspecific.Forspecificreferences,onlythecitedversionapplies.Fornon-specificreferences,thelatestversionofthereferenceddocument(includinganyamendments)applies.

NOTE: Whileanyhyperlinksincludedinthisclausewerevalidatthetimeofpublication,O-RANcannotguaranteetheirlong-termvalidity.

Thefollowingreferenceddocumentsarenotnecessaryfortheapplicationofthepresentdocument,buttheyassisttheuserwithregardstoaparticularsubjectarea.

[i.1] 3GPPTR21.905:"Vocabularyfor3GPPSpecifications".

[i.2] O-RAN.WG9.XTRP-REQ-v01.00:"XhaulTransportRequirements".

[i.3] 3GPPTS38.801v14.0.0,03/2017:"Studyonnewradioaccesstechnology:Radioaccessarchitectureandinterfaces".

[i.4] 3GPPTS38.300:"5G;NR;NRandNG-RANOveralldescription;Stage-2".

[i.5] 3GPPTS38.101-1:"NR;UserEquipment(UE)radiotransmissionandreception;Part1:Range1Standalone".

[i.6] 3GPPTS38.133:"NR;Requirementsforsupportofradioresourcemanagement".

[i.7] /en/blog/2021/6/what-why-how-5g-carrier-aggregation

[i.8] /networks/mobile-networks/carrier-aggregation/

[i.9] 3GPPTS38.331:"5G;NR;RadioResourceControl(RRC)Protocolspecification".

[i.10] 3GPPTS38.420:"5G;NG-RAN;Xngeneralaspectsandprinciples".

[i.11] 3GPPTS38.101-3:"NR;UserEquipment(UE)radiotransmissionandreception;Part3:Range1andRange2Interworkingoperationwithotherradios".

[i.12] 3GPPTS38.473;F1applicationprotocol.

[i.13] 3GPPTS38.423;Xnapplicationprotocol.

[i.14] O-RANALLIANCEO-RAN.WG4.CUS.0:"Control,UserandSynchronizationPlaneSpecification".

[i.15] O-RANALLIANCEO-RAN.WG4.MP.0:"ManagementPlaneSpecification".

[i.16] O-RANALLIANCEO-RAN.WG1.Use-Cases-Detailed-Specification:"UseCasesDetailedSpecification".

[i.17] O-RAN.WG1.OAD,"O-RANArchitectureDescription".

3 Definitionofterms,symbolsandabbreviations

3.1 Terms

Forthepurposesofthepresentdocument,thetermsgivenin[i.1],O-RANWG1.OAD

REFref_wg1_oad\h

[i.17]

andthefollowingapply:

carrieraggregation:aggregationoftwoormoreNRorE-UTRAcomponentcarriersinordertosupportwidertransmissionbandwidths.

PrimaryO-DU: O-DUwherePCellishostedforaparticularUE.

SecondaryO-DU:O-DUwhereSCellishostedforaparticularUE.

3.2 Symbols

Forthepurposesofthepresentdocument,thesymbolsgivenin[i.1]andthefollowingapply:

NRB Transmissionbandwidthconfiguration,expressedinunitsofresourceblocks(forE-UTRA)

3.3 Abbreviations

Forthepurposesofthepresentdocument,theabbreviationsgivenin[i.1],O-RANWG1.OAD

REFref_wg1_oad\h

[i.17]

andthefollowingapply:

C&MPlane ControlandManagementPlane

C-RAN CentralizedRAN

C-RNTI CellRadioNetworkTemporaryIdentifier

D-RAN DistributedRAN

EMS ElementManagementSystem

MCG MasterCellGroup

MNO MobileNetworkOperator

Near-RTRIC NearrealtimeRANIntelligentController

Non-RTRIC Non-realtimeRANIntelligentController

PCI PhysicallCellIdentity

SCG SecondaryCellGroup

SMO ServiceManagementandOrchestration

vRAN VirtualizedRAN

4 Objectivesandrequirements

4.1 Currentchallengesforspectrumaggregationinmulti-vendorRAN

Spectrumaggregationacrossdifferentbandsplaysanessentialroleforuserexperienceandefficientuseoffrequencyresources.AsMNOsgetaccesstonewNRspectrum,theyusuallydesiretoaggregatethecapacityacrossthedifferentbandstoimprovetheuserexperience.Thecoverageareasofdifferentfrequencybandscanbeverydifferent.Therehasbeeninterestfromseveralcompaniesforspectrumaggregationovermulti-vendorRANdeployment,wheredifferentbandsmayhavedifferentcomponentsuppliers.Inadditiontoagreenfieldmulti-vendorRANdeployment,howspectrumcanbeaggregatedwhenanewbandwithanewsupplier(s)isintroducedinanexistingnetworkisanareaofpotentialinterest.

4.2 Objectives

ThepresentdocumentcapturestheoutcomeoftheWG1spectrumaggregationstudyacrossmulti-vendorRANequipment.Theobjectiveofthestudyistodocumentvariousdeploymentscenariosforspectrumaggregationandthendescribesolutionsthatmaptothesedeploymentscenarios.Thesolutionevaluationundervariousconsiderationsdefinedinthepresentdocumentisalsopartofthestudy.

Thedetailedobjectivesofthisstudyitemare:

Captureanddocumentmulti-vendordeploymentscenariostosupportspectrumaggregationinvariousRANconfigurationssuchas

CentralizedRAN,

DistributedRAN,

VirtualizedRAN,

LegacyRAN(i.e.,alreadydeployed).

Captureanddocumentspectrumaggregationusecases:

Intra-bandcontiguousandnon-contiguousinFR1/FR2,

Inter-bandwithinandacrossFR1/FR2,

Duplexingschemes(FDD/TDD).

CapturethespectrumconsiderationsandUEconsiderationsfordifferentspectrumaggregationtechniques.

Identifyanddocumenttheevaluationcriteriaforthedifferentspectrumaggregationtechniquessuchas:

Minimizecomplexity,e.g.,requiredinterfacebandwidthandlatency,

Minimizeimpacttointer-operabilitytestingandstandardizationeffort,

Increaseperformanceandlowerlatency,

MinimizeimpactonO-RANarchitecture,

MinimizeUEimpact,

Alignswith3GPPRANdesign,

Increasespectralefficiencyofcombinedcarriers,

Increasecoverage,

Addresssecurityconcernswithdifferentsolutions.

Identifythedifferentsolutionspossibleforspectrumaggregation:

Dualconnectivity,

IntraO-DUCA(MultiO-RUorSharedO-RU),

InterO-DUCA.

Identifythedifferentinterfacesusedforsupportingthespectrumaggregationtechniquessuchas

XnInterface(Dualconnectivity),

F1Interface(Dualconnectivity),

LLSinterface(IntraO-DUCA),

D2Interface(ProposedinterfacetosupportInterO-DUCA).

Evaluateandcomparethesolutionsdefinedin5)againsttheevaluationcriteriamentionedin4).

BrieflycovertheoutlineoftheproposedInterO-DUCAsolution.

5 Scenariosandconsiderations

5.1 Overview

Initsmostgeneralform,deployedRANnetworkfunctionsinanMNO'snetworkcanbesourcedfromasingle-vendorormultiplevendors.TheconnectivitybetweentheRANlogicalfunctionsmayneedtoconsideridealandnon-idealtransportscenarios.RANdeploymentscanalsobemixedinvolvingacombinationofD-RAN,C-RANandvRANdeployments.

REFtab_mvsa_arch\h

Figure5.1-1

showsthereferencedeploymentarchitectureusedinthepresentdocument.Inadditiontobeingpurpose-builtorvirtualized,gNBnetworkfunctionscanbeprocuredfrommultiplevendors.Dependingondeploymentfactors,O-DUscanbeconnectedtothesameordifferentO-CU-CPsandO-CU-UPs.

Figure5.1-

SEQmyfig\*ARABIC\s5

1

:Multi-vendorequipmentdeploymentarchitecture

5.2 Deploymentscenarios

5.2.1 Co-locateddeployments

Overview

ThisclauseconsidersthedeploymentscenarioswhererelevantO-RANnetworkfunctionsforaggregationoffrequenciesareco-located.Inthisusecase,O-RANNFsfrommultiplevendors,supportingthesameordifferentband/duplexingcapabilityareco-located.O-RANNFscanbesupportingasplitRANarchitecture,oritcanbeamonolithicintegratedgNB.BysupportingspectrumaggregationacrosstheO-RANNFsthatareco-located,userthroughput,cellcoverageetc.canbeimproved.

UsecasesbasedondifferentcombinationsofO-RANNFsaredescribedinclauseand.

AdditionofnewO-RANNFsco-locatedwithexistingintra/inter-bandO-RANNFssupportingsame/differentduplexingcapability

Thefollowingusecasecoversthescenariowherespectrumaggregationisneededbetweentheco-locatedO-RANNFs.

AnMNOcanhavenetworkfunctionsuchasO-CU-CP,O-CU-UP,O-DUandO-RUwitheitherTDDorFDDorbothduplexingcapabilitiesinstalledatacellsite.Toincreasethecapacityofthesite,MNOmayneedtoinstallanewcellwhichcouldbeoperatinginthesame/differentband.Inonedeploymentscenario,depictedin

REF_Ref146033163\h

Figure-1

,MNOdeploysanewO-RU,fromanewvendor,toaddanewfrequencybandtotheexistinginfrastructure.ThenewO-RUcanbeconnectedtotheexistingO-DUthroughopenfronthaul,asshownin

REF_Ref146033163\h

Figure-1

(b).Insomeinstances,hardwareorsoftwarerealizingtheexistingO-DUmaybelimitedbycapacityandcannothostthenewcell.OneoftheoptionsavailablefortheMNOistoenhancethecapacityofexistinghardwareorsoftware.Anotherpossibilityistoinstallanewhardwareorsoftwareforcapacityenhancements.ThenewhardwarecanbeintegratedwiththeexistinghardwaretorealizethesamelogicalO-DU(asin

REF_Ref146033163\h

Figure-1

(b)),oritcanrealizeanewlogicalO-DUoperatinginparalleltothefirstO-DUasshownin

REF_Ref146033163\h

Figure-1

(c).

Figure-

SEQmyfig\*ARABIC\s5

1

:AddingnewO-RUtosupportanewfrequencybandorcarrierinaco-locateddeployment.(a)existingdeployment.(b)additionofnewO-RU.(c)additionofnewO-RUandO-DU.

Insomeotherdeploymentscenarios,deployedO-DU(s)mayhavelimitedcapacity,mayonlysupportoneduplexingmethodorcansupportalimitedsetofsubcarrierspacingforreal-timeprocessing.TheMNOmaychoosetodeployanewO-DUvendortosupportanewO-RU,e.g.,vendorcasshownin

REFfig_colo_du\h

Figure-2

.IftheMNOchoosestoinstallanewO-DU,itcanbesupportingthesameordifferentduplexingcapabilityorsubcarrierspacing.IfO-CU-CPandO-CU-UParecapabletohandlethenewlyinstalledO-DU,thenewO-DUcanbeconnectedtosameO-CU-CPandO-CU-UP.Otherwise,anewO-CU-CPandO-CU-UPmayalsoneedtobeinstalled.TheMNOcanchoosetheO-CU-CPs,O-CU-UPs,O-DUsorO-RUsfromthesamevendorordifferentvendors.

Figure-

SEQmyfig\*ARABIC\s5

2

:Spectrumaggregationinco-locatedO-DU

Co-locatedintra/inter-bandmonolithicgNBswithsameordifferentduplexingcapability

ThisusecasecoversthedeploymentscenariowhereamonolithicgNBisinstalledatcellsite.AsshowninFigure

REFfig_colo_gnb\h

-1

,toincreasetheusercapacitywithspectrumaggregation,theMNOcaninstalladditionalhardwareandsoftwareeithertoupgradethecapacityofexitinggNBortosupportanewgNBoperatinginparalleltotheexistinggNB.ThenewlyinstalledgNBcanoperateinthesamebandordifferentbandastheexistinggNB.BoththegNBsmayalsosupportsameordifferentduplexingcapability.ThenewgNBcanbemonolithicordisaggregated.BysupportingspectrumaggregationbetweenthesegNBs,improvedcoverageandthroughputcanbeachieved.

Figure-

SEQmyfig\*ARABIC\s5

1

:Spectrumaggregationinco-locatedgNBs

5.2.2 Non-co-locateddeployments

Thisclausecoversthedeploymentscenarioswhereaggregatedfrequenciesareservedbyequipmentsthatarenotco-located.

Inthisusecase,gNBsaresupportingsplitRANarchitectureanditisdistributedintodifferentO-RANnetworkfunctions.O-CU-CP/O-CU-UPmightberesidingatacentralizedlocationwhileO-DUsmaybelocatedatcellsiteoratacentrallocation.Twocasesareconsideredforthisscenario:

SingleO-CU-CPandO-CU-UPconnectedtomultipleO-DUslocatedatcellsite.

EachO-DUatcellsiteisconnectedtodifferentO-CU-CPandO-CU-UP.

Inonedeploymentscenario,thenetworkMNOmaydeployanewO-RUfromadifferentvendor,toaddanewfrequencyband,thatisnotco-locatedwithotherO-RUsservingthesamegeographicarea.Asanexample,currentlydeployedO-RUsinanetworkmayservealargeareaandtheMNOmaydecidetoserveahigh-demandzonewithinthelargercoverageareabydeployingadditionalspectrum.Thisisshownin

REF_Ref146033118\h

Figure5.2.2-1

below.BysupportingspectrumaggregationacrossalltheO-RUsservingthesamearea,userthroughput,cellcoverageetc.canbeimproved.

Figure5.2.2-

SEQmyfig\*ARABIC\s5

1

:DeployingadditionalO-RUinanon-co-locatedmanner.(a)existingdeployment.(b)additionofnon-co-locatedO-RUconnectedtoexistingO-DU.(c)additionofnon-co-locatedO-RUandO-DU.

Insomeotherdeploymentscenarios,asshownin

REFfig_noncolo_ran\h

Figure5.2.2-2

below,deployedO-DU(s)ateachcellsitemayhavelimitedcapacity,ormayonlysupportoneduplexingmethod,orcansupportalimitedsetofsubcarrierspacing.TheremayalsobesomeotherO-DUswhicharenotco-locatedwiththeexistingO-DUs.ButtheseO-DUscanbeusedtogethertoovercomethelimitationsofexistingcellsitedeployment.AlltheO-DUscanbesupportingthesameordifferentduplexingcapability.TheO-DuscanbeconnectedtothesameordifferentO-CU-CPsandO-CU-UPs.Also,theseO-DUsmaybeprovidedbythesamevendorordifferentvendors.ThebandconfigurationalsocanbethesameordifferentforalltheseO-DUs.Bysupportingspectrumaggregationacrossdifferentcellsservedbysameordifferentnon-co-locatednetworkfunctions(O-RU,O-DU,O-CU-CP,O-CU-UP),enduserthroughputandcellcoverageofdifferentfrequencybandscanbeimproved.

Figure5.2.2-

SEQmyfig\*ARABIC\s5

2

:Spectrumaggregationinnon-co-locatedRANcomponents

5.2.3 Transportassumptions

Thisclausecoverstheaspectofconnectivitybetweenthedifferentequipmentforsupportingspectrumaggregationtoconsideridealandnon-idealtransportconsiderations.

NetworkdevicescanbeconnecteddirectlyorthroughL2/L3switcheswithintherangethatmeetsdelayrequirements.TherearemultipleconnectivityclassesforthetransportconnectingtheNFs.SomeguidelinesareprovidedinO-RANXhaulTransportRequirementsdocument

REFxhaul_reqs\h

[i.2]

.

Formoreinformationonthelatencyrequirements,seeAnnex

A.Theoutlinedsolutionsinthepresentdocumentaccountforidealandnon-idealtransportscenarios.

5.3 Considerationsforspectrumaggregationtechniques

5.3.1 UEconsiderationsfromnetworkperspective

SpectrumaggregationbetweenRANNFscanbeachievedbymultipletechniquessuchascarrieraggregationordualconnectivity.TheusageofthesetechniquesinanetworkarealsodependentonUEcapability.DifferentspectrumaggregationtechniquescanimpacttheUEperformancedifferently.UsecaseconsiderationsforUEperformanceandcapabilitiesarediscussedbelow.

Spectrumaggregationtomaximizecomponentcarrier(CC)combinationsbasedonUEcapability:Numberofcarrierfrequencycombinationsplayanimportantroleinspectrumaggregation;largerthenumber,betterthethroughputandcoverage.UEssupportingdifferent3GPPreleasesdifferinCCcombinationcapabilities.NumberofavailableCCsforspectrumaggregationdependsonaparticularspectrumaggregationtechnique.Forexample,UEs,whicharesupportingearlierR15orR163GPPreleases,maybelimitedinsupportingCCcombinationsforsomeofthespectrumaggregationtechniquesbasedonthebandandbandwidthconsiderationsforthecomponentcarriers.ThisneedstobeconsideredforbothSAandNSAUEs.

UEpowerconsumption:Whileconsideringspectrumaggregationtechniques,powerconsumptionbyUEsatvariousdistancesfromthecellsiteneedstobeconsidered.SpectrumaggregationtechniquesshouldminimizeimpactonUEpowerconsumption.

5.3.2 Spectrumconsiderations

Overview

MostcommercialRANdeploymentsinvolvemultiplefrequencybands.Spectrumaggregationacrossdifferentbandsshouldconsiderfrequencybandcharacteristics(coverage,supportedSCS,duplexing).

Thefollowingclausescoverusecases,suchas(i)intra-bandcontiguousandnon-contiguousinFR1/FR2,(ii)inter-bandwithinandacrossFR1/FR2,and(iii)considerationsforDL-ULlinkbalanceinhigh-frequencybandsanddifferentduplexingschemes(FDD/TDD).

Duplexing(FDD/TDD)

SpectrumusageisregulatedintoFDDandTDDdomains.WhileFDDusesseparatefrequenciesfortheuplinkandthedownlink,TDDusesasinglefrequencyforbothuplinkanddownlink.

Generally,theunpairedspectrumforTDDisallocatedinhigherfrequenciesthanFDD.Thelow-bandFDD,duetophysicalpropagationcharacteristics,offersawidercoverageareathanthehigher-frequencyTDDspectrum.Typically,thelow-bandFDDislimitedincapacity.Mid-bandTDDhasahigherbandwidthandcapacitycomparedtothelow-bandFDD.However,mid-bandTDDuplinkcoverageismorelimitedthanthelow-bandFDD.SpectrumaggregationacrossFDDandTDDcarrierscanimproveTDDcellcoverageanddeliverhigherthroughputthanaTDD-onlysolution.

REFfig_tdd_fdd_ca\h

Figure-1

illustratesapossiblewaytoaggregatethelow-bandFDDcarrier(primarycell)andmid-bandTDDcarrier(secondarycell).Byusingthelow-bandFDDastheprimarycell(PCell),thecoverage-limitingULdataandcontrolchannelsofthemid-bandTDDcarriercanbemovedtothelow-bandFDD.Thisincreasestheoverallmid-bandcellcoverage,whichmeansthatnowthemid-bandspectrumcanbeaccessedbymoreusersinthenetwork.Byusingthemid-bandTDDassecondarycell(SCell),thedownlinkthroughputcanbesignificantlyimproved.Thisusecaseprovidestheuniquecapabilityofaggregatinglow-bandFDDandmid-bandTDDforhigherpeakratesandincreasedcellcoverage.

Figure-

SEQmyfig\*ARABIC\s5

1

:Aggregatelow-bandFDDcarrier(PCell)andmid-bandTDDcarrier(SCell)

MaximizethenumberofCCsbeingaggregatedirrespectiveofinterorintra-band

MNOcanaccessmultiplecarriersacrossvariousbandsenabledby5Ginlow,mid,andhighfrequencies.NationalregulatorsoftengrantadditionalspectrumlicensestoMNOsinaphasedmanner.Asaresult,MNOscanofferservicesinmultiplefrequencybandsandaddspectruminaphasedmanneratlaterdatesincludinglow,midandhigh-frequencybands.Toincreasebandwidthandbitrateaggregation,MNOsneedtoconsiderspectrumaggregationfromsameordifferentvendor’sequipment,involvinglow,mid,andhigh-bandcellswithconsiderationsonavailability,functionality,costetc.Thisenablestheuseofdownlinkforallaggregatedcellswhileensuringconnectionstabilitythroughacommonuplinkonthelowerfrequencyaggregatedcarriers.TheMNOsprimarilybenefitfromleveragingthecumulativespectrumbandwidthoftheseallocationsfromdifferentvendorstoachievehigherdateratesforendusers.

REFfig_3ca\h

Figure-1

illustratesascenariowherethreeco-locatedandoverlaidcellsareprovidedbydifferentvendorequipment;alow-bandcarrier,amid-bandcarrier,andahigh-bandcarrier.MaximizingthenumberofCCsbeingaggregatedcanbeconsideredforbothNSAandSAscenarios.

Figure-

SEQmyfig\*ARABIC\s5

1

:Aggregatemultiplecellsfromdifferentvendorequipment

Spectrumaggregationbetweenlowbandandmid/highband

Thisusecasecoverstheneedofspectrumaggregationbetweenlowandmid/highband.LetusconsiderthattheMNOhasO-DUs/O-RUsoperatingonlowbandallocatedtotheMNO,deployedinthecellsite.Later,theregulatorybodyallocatesanewmid/highbandspectrumtothesameMNO.Bysupportingaggregationbetweenlowandmid/highbandcells,theMNOcanachievebettercoverageformid/highbandandcanimprovethethroughputforUEsconnectedtolowbandcells.IfexistingO-DUwithlowbandisrestrictedbycapacityissueandhencecannothostnewcellswithmid/highband,anewO-DUmayberequiredtobeinstalledtoutilizethenewlyallocatedband.ExistingcellmaybesupportinglowbandFDDcapabilitywhilenewcellsmaybesupportinghighormidbandwithTDDduplexingcapability.Theintroductionofnewmid/highbandcellscanreducethecapacitydemandofthelowbandcellasUEsingoodcoverageconditionscanbeservedbythenewcellasshownin

REF_Ref143092761\h

Figure-1

.

Figure-

SEQmyfig\*ARABIC\s5

1

:Exampleofspectrumaggregationbetweenlowandmid/highband

Intra-bandspectrumaggregation(contiguousornon-contiguous)

Thisusecasecoverstheneedofspectrumaggregationbetweentheintrabandcells.MNOdeployscellswithspectrumallocatedfromBandB.LatermorespectrumfromsameBandBisallocatedtotheMNO.Newlyallocatedspectrumcanbecontiguousornon-contiguous.TheMNOwantstoinstallcellsfromsameord