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TABLEOFCONTENTS

INTRODUCTION 3

WIRELESSDATAMARKET 5

Trends 5

EDGE/UMTS/HSDPADeployment 7

Statistics 8

TECHNOLOGYCAPABILITIESANDMIGRATION 9

TechnicalApproaches(TDMA,CDMA,OFDM) 10

3GPPEvolutionaryApproach 11

GPRSandEDGE 13

EDGEDeployment 19

EDGEEvolution 20

UMTS/HSPATechnology 26

UMTSRelease99DataCapabilities 28

HSDPA 29

HighSpeedUplinkPacketAccess(HSUPA) 33

EvolutionofHSPA(HSPA+) 34

HSPAVoiceoverIP 35

3GPPLongTermEvolution(LTE) 36

4G 38

UMTSTDD 38

TD-SCDMA 39

INFRASTRUCTUREANDSERVICEADVANCES 40

IPMultimediaSubsystem(IMS) 40

MultimediaBroadcast/MulticastService(MBMS) 41

SystemArchitectureEvolution(SAE) 41

EDGE/HSPA/LTEDEPLOYMENTANDMIGRATION 43

COMPETINGTECHNOLOGIES 45

CDMA2000 46

WiMAX 48

FlashOFDM 50

IEEE802.20 50

Wi-Fi 50

MarketFit 51

COMPARISONOFWIRELESSTECHNOLOGIES 53

DataThroughput 53

HSDPAThroughputinRepresentativeScenarios 56

Release99andHSUPAUplinkPerformance 58

Latency 59

SpectralEfficiency 60

PowerConsumptionComparison 65

CostandVolumeComparison 66

CompetitiveSummary 67

CONCLUSION 68

ADDITIONALINFORMATION 70

REFERENCES 70

ACRONYMS 74

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Introduction

UniversalMobileTelecommunicationsSystem(UMTS)/HighSpeedPacketAccess(HSPA)technologyanditsevolutiontobeyondThirdGeneration(3G)willcompetewithanyandallmobilewirelesstechnologiesavailabletodayandinthefuture.BuildingonthephenomenalsuccessofGlobalSystemforMobileCommunications(GSM),theGSM/UMTSecosystem,unmatchedbyanyothermobilewirelesstechnologyandpossiblyunmatchedbyanyothercommunicationtechnologyever,isnotjustafuturedream.Itisherenow.UMTS/HSPAhasmanykeytechnicalandbusinessadvantagesoverothermobilewirelesstechnologies.

Whereasotherwirelesstechnologiesshowgreatpotentialonpaper,UMTStodayhasglobalcommercialdeploymentsprovidingcustomersmobilebroadbandservice.

OperatorsworldwidearenowdeployingHighSpeedDownlinkPacketAccess(HSDPA),oneofthemostpowerfulcellular-datatechnologieseverdeveloped.HSDPA,whichwillbewidelydeployedin2006,followsthesuccessfuldeploymentofUMTSnetworksaroundtheworldand,formanyofthesenetworks,isarelativelystraightforwardupgrade.Infact,someoperatorswilldeployUMTSenhancedwithHSDPAimmediatelyupontheirinitiallaunch.

TheUMTStoHSPDAupgradeissimilartoEnhancedDataRatesforGSMEvolution(EDGE),whichhasalreadyproventobearemarkablyeffectiveupgradetoGSMnetworks,andisnowsupportedbyalargenumberofoperatorsandvendorsworldwide.

HighSpeedUplinkPacketAccess(HSUPA1)willquicklyfollowHSDPA,withthecombinationofthetwotechnologiesbeingcalledsimplyHighSpeedPacketAccess(HSPA).HSPAisstronglypositionedtobethedominantmobiledatatechnologyfortherestofthedecade.ToleverageoperatorinvestmentsinHSPA,standardsbodiesareexaminingaseriesofenhancementstocreate“HSPAEvolution,”alsoreferredtoas“HSPA+.”HSPAEvolutionrepresentsalogicaldevelopmentoftheWidebandCodeDivisionMultipleAccess(WCDMA)approach,providingthestepping-stonetoanentirelynewThirdGenerationPartnershipProject(3GPP)radioplatformcalled3GPPLongTermEvolution(LTE).LTE,whichusesOrthogonalFrequencyDivisionMultiple(OFDM),shouldbereadyfordeploymentinthe2009timeframe.Simultaneously,standardsbodies,recognizingthesignificantworldwideinvestmentsinGSMnetworks,arenowdefiningenhancementsthatwillsignificantlyincreaseEDGEdatacapabilitiesthroughaneffortcalledEnhancedGSM/EDGERadioAccessNetwork(GERAN).

Combinedwiththeseimprovementsinradio-accesstechnologyarenewapproachestoinfrastructure,suchasIPMultimediaSubsystem(IMS)andSystemArchitectureEvolution(SAE).Thesewillfacilitatenewtypesofservices,theintegrationoflegacyandnewnetworks,theconvergencebetweenfixedandwirelesssystems,andthetransitionfromcircuit-switchedapproachesforvoicetraffictoafullypacket-switchedmodel.

Theresultisabalancedportfolioofcomplementarytechnologiesthatprovidesoperatorsmaximumflexibilityinhowtheyenhancetheirnetworksovertimeaswellassupportbothvoiceanddataservices.ThispaperdiscussestheevolutionofEDGE,HSPAenhancements,3GPPLongTermEvolution,thecapabilitiesofthesetechnologies,andtheirpositionrelativetosomecompetingtechnologies.

1WhiletheprimarydownlinktrafficchannelsupportingHSDPAservicesisasharedchanneldesignedforthesupportofservicesdeliveredthroughthePacket-SwitchedDomain,theprimaryuplinktrafficchanneldefinedfor“HSUPA”isadedicatedchannelthatcouldbeusedforservicesdeliveredeitherthroughtheCircuit-SwitchedorthoughthePacket-SwitchedDomains.Nevertheless,byextensionandforsimplicity,theWCDMAenhancedUplinkcapabilitiesareoftenidentifiedintheliteratureasHSUPAandhence,thistermanditsextensionHSPAarealsousedinthiswhitepaper.

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Followingaresomeoftheimportantobservationsandconclusionsofthispaper:

GSM/UMTShasanoverwhelmingglobalpositionintermsofsubscribers,deployment,andservices.Itssuccesswillmarginalizeotherwide-areawirelesstechnologies.

The3GPProadmapprovidesoperatorsmaximumflexibilityindeployingandevolvingtheirnetworks.Theroadmapiscomprisedofthreeavenues,includingthecontinuedevolutionofGSMsystemcapabilities,UMTSevolutionand3GPPLTE.Eachtechnologyisdesignedtocoexistharmoniouslywiththeothers.

EDGEtechnologyhasprovenextremelysuccessfulandiswidelydeployedonGSMnetworksglobally.EDGEimprovementswillbeabletomorethanquadruplecurrentEDGEthroughputrates.

UMTS/HSPArepresentstremendousradioinnovationandcapability,whichallowsittosupportawiderangeofapplications,includingvoiceanddataonthesamedevices.

ThehighspectralefficiencyofHSPAfordataandWidebandCDMA(WCDMA)forvoiceprovidesUMTSoperatorsanefficienthigh-capacitynetworkforallservices.Inthelongerterm,UMTSprovidesforacleanmigrationtopacket-switchedvoice.

Incurrentdeployments,HSDPAusersunderfavorableconditionsregularlyexperiencethroughputrateswellinexcessof1megabitpersecond(Mbps).Thesepeakuser-achievablethroughputrateswillincreasewithplannedenhancementsofHSDPA.

HSUPAusersunderfavorableconditionswillexperiencepeakachievableratescloseto1Mbpsintheuplink.

ContinualHSPAenhancementsareplanned.Beginningwithenhanceduplinkperformance,advancedreceiversinthemobileandinthebasestation,andthenMultipleInputMultipleOutput(MIMO),theseimprovementswillextendHSPAcapabilityevenfurther.

3GPPisdevelopingaLongTermEvolutiontechnologypathwiththegoalofinitiallydeployingnext-generationnetworksinthe2009timeframe.Expectpeakdownlinkspeedsof100Mbpsandpeakuplinkspeedsof50Mbpsin20MHzchannels.LTEusesOFDMonthedownlinkandSingleCarrierFrequencyDivisionMultipleAccess(SC-FDMA)ontheuplink.

OFDMapproachesmayprovidehighspectralefficiencyandhighpeakrates.However,HSPA+systemscouldmatchOFDM-basedapproachesinspectralefficiencyandpeakdataratesin5+5MHzradioallocationsthroughtheuseofequalizersandinterferencecancellationtechniques.

Withrelativeease,operatorscantransitiontheirGeneralPacketRadioService(GPRS)networkstoEDGEandtheirUMTSnetworkstoHSDPA/HSUPAand,inthefuture,toHSPA+andLTE.Insomecasesoperatorscanattaintheseimprovementsbyupgradingthesoftwareintheirplatforms(i.e.,nohardwarechangerequired).

WithaUMTSmulti-radionetwork,acommoncorenetworkcanefficientlysupportGSM,WCDMA,andHSPAaccessnetworks,offeringhighefficiencyforbothhighandlowdataratesaswellasforbothhighandlowtrafficdensityconfigurations.

VoiceoverInternetProtocol(VoIP)withHSPAwilleventuallyaddtovoicecapacityandreduceinfrastructurecosts.Inthemeantime,UMTSenjoyshighcircuit-switchedvoicespectralefficiencyandcancombinevoiceanddataonthesameradiochannel.

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LTEassumesafullInternetProtocol(IP)networkarchitectureandisdesignedtosupportvoiceinthepacketdomain.

Ongoing3GPPevolutionincludessignificantenhancementswitheachnewspecificationrelease.Theseincludehigherthroughputrates,enhancedmultimediasupport,andintegrationwithothertypesofwirelessnetworks.

Thispaperbeginswithanoverviewofthemarket,lookingatadoptionofservicesanddeploymentofGSM-UMTStechnologies.Itthenexplainsthecapabilitiesandworkingsofthedifferenttechnologies,includingGPRS,EDGE,WCDMA2,HSPA,HSPAEvolutionandLTE.Thisdiscussionincludestheprogressionofcapability,deployment,andmigrationconsiderations.Thepaperthenexaminesotherwirelesstechnologies,includingCDMA2000andWorldwideInteroperabilityforMicrowaveAccess(WiMAX).Finally,thepapertechnicallycomparesdifferentwirelesstechnologieswithrespecttoperformanceandspectralefficiency.

WirelessDataMarket

AttheendofJune2006,twobillionoftheworld’s2.41billioncellularsubscribersusedGSM/UMTS.Informa’sWorldCellularInformationService3projectsthreebillionGSM/UMTScustomersby2009,with511millionofthesesubscribersusingUMTSservices.Clearly,GSM/UMTShasestablishedglobaldominance.Althoughvoicestillconstitutesmostcellulartraffic,wirelessdatanowexceeds10percentofAverageRevenuePerUser(ARPU),andthisnumbercouldeasilydoublewithinthreeyears.OperatorsacrosstheAmericasareconfirmingthistrendwiththeirreportsofrisingdataARPU.Forinstance,forthesecondquarterof2006,CingularWirelessreportedARPUfromdataservicesrose38percentto

$5.77permonth.T-MobilereporteddataARPUrepresented10.9%ofblendedARPUinthesecondquarterof2006,ascomparedto10.1%inthefirstquarterof2006,and7.5%inthesecondquarterof2005.RogersWirelessofCanadareporteda65.1%liftindatarevenues,representing10.5%ofthetotalnetworkrevenueofthequarter.

Thissectionexaminestrendsanddeploymentandthenprovidesmarketdatathatdemonstratestherapidgrowthofwirelessdata.

Trends

Usersareadoptingwirelessdatainawiderangeofapplications,includinge-mail,gamedownloads,instantmessaging,ringtones,andvideoaswellasenterpriseapplicationssuchasgroupcollaboration,enterpriseresourceplanning,customerrelationshipmanagement,anddatabaseaccess.Thissimultaneousadoptionbybothconsumersforentertainment-relatedservicesandbusinessestoenhanceproductivityincreasesthereturn-on-investmentpotentialforwirelessoperators.

Anumberofimportantfactorsareacceleratingadoptionofwirelessdata.Theseincludeincreaseduserawareness,innovativefeaturephones,powerfulsmartphones,andglobalcoverage.Buttwofactorsstandout:networkcapabilityandapplications.TechnologiessuchasGSM,WCDMAandHSPAprovidethecapabilitytosupportawiderangeofapplications,includingstandardnetworkingapplicationsaswellasthosedesignedfor

2Althoughmanyusetheterms“UMTS”and“WCDMA”interchangeably,inthispaperweuse“WCDMA”whenreferringtotheradiointerfacetechnologyusedwithinUMTSand“UMTS”torefertothecompletesystem.HSDPAisanenhancementtoWCDMA.

33GAmericaspressreleaseofJune13,2006.

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wireless.Meanwhile,applicationandcontentsuppliersareoptimizingtheirapplications,orinmanycasesdevelopingentirelynewapplicationsandcontent,totargettheneedsanddesiresofmobileusers.

Computingitselfisbecomingevermoremobile,andnotebooks,PDAs,andsmartphonesarenowprevalent.Infact,allphonesarebecoming“smart”withsomeformofdatacapability.Leadingnotebookvendorsarenowofferingcomputerswithintegrated3Gcapabilities.Lifestylesandworkstylesthemselvesareincreasinglymobile,withmorepeopletravelingforwork,pleasure,orinretirement.Meanwhile,theInternetisbecomingprogressivelymoreintertwinedwithpeople’slives,providingcommunications,information,enhancementsformembershipsandsubscriptions,communityinvolvement,andcommerce.Inthisenvironment,wirelessaccesstotheInternetisapowerfulcatalystforthecreationofnewservicesandnewbusinessopportunitiesforoperatorsaswellasthird-partybusinesses.

Withdataconstitutingarisingpercentageoftotalcellulartraffic,itisessentialthatoperatorsdeploydatatechnologiesthatmeetcustomerrequirementsforperformanceandarespectrallyefficient—especiallyasdataapplicationscandemandsignificantlymorenetworkresourcesthantraditionalvoiceservices.Operatorshaveahugeinvestmentinspectrumandintheirnetworks;dataservicesmustleveragetheseinvestments.Itisonlyamatteroftimebeforetoday’smorethantwobillioncellularcustomersstarttakingfulladvantageofdatacapabilities.Thispresentstremendousopportunitiesandriskstooperatorsastheychoosethemostcommerciallyviableevolutionpathformigratingtheircustomers.TheEDGE/HSPA/LTEevolutionpathsprovidedatacapabilitiestoaddressmarketneeds,deliveringever-higherdatathroughputs,lowerlatencyandincreasedspectralefficiency.

Althoughwirelessdatahasalwaysofferedatantalizingvisionofalways-connectedmobilecomputing,adoptionhasbeenslowerthanthatforvoiceservices.Inthepastseveralyears,however,adoptionhasaccelerated;finally,somemightsay,andthankstoanumberofkeydevelopments.Networksthemselvesaremuchmorecapable,deliveringhigherthroughputsatlowercost.Awarenessofdatacapabilitieshasincreased,especiallythroughthepervasivesuccessofShortMessageService(SMS),wirelesse-mail,downloadableringtones,anddownloadablegames.Widespreadavailabilityofserviceshasalsobeenimportant.Thefeaturesfoundincellulartelephonesareexpandingatarapidrateandtodayincludelargecolordisplays,graphicsviewers,stillcameras,moviecameras,MP3players,instantmessagingclients,e-mailclients,Push-to-talkoverCellular(PoC),downloadableexecutablecontentcapability,andbrowserssupportingmultipleformats.Allthesecapabilitiesconsumedata.Meanwhile,smartphones,whichemphasizearichcomputingenvironmentonaphone,representtheconvergenceof:1)thepersonaldigitalassistant;2)afullycapablemobilecomputer;and3)aphoneinadevicethatisonlyslightlylargerthantheaveragecellulartelephone.Manyuserswouldprefertocarryonedevicethat“doesitall.”

Asaconsequence,thisrichnetworkanddeviceenvironmentisspawningtheavailabilityofawiderangeofwirelessapplicationsandcontent.Why?Applicationandcontentdeveloperssimplycannotaffordtoignorethismarketbecauseofitsgrowingsize—anditsunassailablepotential.Andtheyaren’t.Consumercontentdevelopersarealreadysuccessful,providingdownloadableringtonesandgames.Enabledby3Gnetworkcapability,downloadableandstreamingmusicandvideoarenotfarbehind.Intheenterprisespace,allthemajordevelopersnowoffermobilized“wireless-friendly”componentsfortheirapplications.Actingascatalysts,awidearrayofmiddlewareprovidersaddressissuessuchasincreasedsecurity(e.g.,VirtualPrivateNetworks[VPNs]),switchingbetweendifferentnetworks(e.g.,WirelessLocalAreaNetworks

MobileBroadband:EDGE,HSPA,LTE

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[WLANs]to3G),sessionmaintenanceunderadverseradioconditions,andpolicymechanismsthatcontrolapplicationaccesstonetworks.

Thismarketdataisencouraging.Butrealistically,themarketisstillinrelativeinfancy.Thoughconsumerawarenessofservicesishigherthaneverbefore,manypeoplestilldonotunderstandthetruerangeofdataoptionsavailabletothem.Forexample,onlyrecentlyhaveoperatorsstartedencouragingsmartphonesubscriberstousetheirphonesasmodemsfortheirlaptops.However,anumberofpowerfulcatalystswillspurwirelessdatainnovation.Pricingforunlimited4usageplanshasdeclinedbyasmuchasathird,encouraginggreaternumbersofuserstoadoptdataservices.Operatorsareseeingconsiderablesuccesswithsalesofmusic.NewcapabilitiessuchasvideosharingwillsoonbeenabledbyIMS,whichwillalsofacilitatefixed/mobileconvergenceandseamlesscommunicationsexperiencesthatspancellularandWirelessFidelity(Wi-Fi)networks.Location-basedservices,mobilecommerce,andotherapplicationenablerswillhelpfuelgrowthtoo.

Intheenterprisespace,thefirststageofwirelessdatawasessentiallytoreplacemodemconnectivity.Thenextistoofferexistingapplicationsonnewplatformslikesmartphones.Butthefinal,andmuchmoreimportant,changeiswherejobsarereengineeredtotakefulladvantageofcontinuousconnectivity.Allthistakestime,butthemomentum—inthedirectionofincreasedefficiency,increasedconvenience,andincreasedentertainment,allfueledbywirelessdata—isunstoppable.

Thekeyforoperatorsisenhancingtheirnetworkstosupportthedemandsofconsumerandbusinessapplicationsastheygrow,alongwithcomplementarycapabilitiessuchasIP-basedmultimedia.ThisiswheretheGSMfamilyofdatatechnologiesisparticularlycompelling.Notonlydoesitprovideaplatformforcontinualimprovementsincapabilities,butitdoessooverhugecoverageareasandonaglobalbasis.

EDGE/UMTS/HSDPADeployment

NearlyeveryGSMnetworkintheworldtodaysupportsGSMdataservice(GPRS),makingitthemostbroadlyavailableIP-basedwirelessdataserviceeverdeployed.TheGSMEDGEfeatureisanothersuccessstory.AsofSeptember2006,morethan239operatorsin121countriesaroundtheworldwereusingEDGEintheirGSMnetworks.Thisincludes160operatorsofferingcommercialservicein91countriesand74operatorsinvariousstagesofdeployment.5

EDGEhasreachedcriticalmassintermsofcoverageofpopulation,geography,infrastructure,anddevices.Today,GSMoperatorswithEDGEhaveoverhalfabillionpotentialcustomerswithintheirnetworks.BecauseoftheverylowincrementalcostofincludingEDGEcapabilityinGSMnetworkdeployment,virtuallyallnewGSMinfrastructuredeploymentsarealsoEDGEcapableandnearlyallnewmid-tohigh-levelGSMdevicesincludeEDGEradiotechnology.

Meanwhile,UMTShasestablisheditselfglobally.NearlyallWCDMAhandsetsarealsoGSMhandsetssoWCDMAuserscanaccessthewidebaseofGSMnetworksandservices.Therearenownearly75millionUMTScustomersworldwideacross135commercialnetworks.Fifty-oneoperatorsin33countriesareofferingHSDPAservices,andan

4Typically,somerestrictionsapply.

5Informationcompiledby3GAmericasfromInformaTelecoms&Media,WorldCellularInformationServiceandpubliccompanyannouncements,September2006.

MobileBroadband:EDGE,HSPA,LTE

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additional54operatorshavecommittedtothetechnology.6ItislikelythatmostUMTSoperatorswilldeployHSDPAfortwomainreasons:One,theincrementalcostofHSDPAisrelativelylow;andtwo,HSDPAmakessuchefficientuseofspectrumfordatathatitresultsinamuchloweroverallcostpermegabyteofdatadelivered.

Statistics

TheU.S.wirelessdatamarketisgrowingatanimpressiverate.ACellularTelecommunications&InternetAssociation(CTIA)survey7indicatesthatUSrevenuesfromwirelessdataservicesincreased86percentinthepastyear,resultingin$8.58billioninrevenuein2005.AccordingtotechnologyandstrategyconsultingfirmChetanSharma8,thetopfourU.S.carriershadover$6.3billioninwirelessdatarevenuesduringthefirsthalfof2006,andwirelessdataservicerevenuesfor2006arelikelytogrow75percentover2005figures.SMSanddatatransportstilldrivethebulkofdatarevenues,buttheirpercentageshareisdeclining.

Thisisconsistentwithwirelessdata'sglobalgrowth.Lastyear'sglobalrevenuesfrommobiledataservicesexceeded$100billion,anddatarevenuegrowthremainedstronginto2006withQ1growthof17percentfromayearago,accordingtoInformaTelecomsandMedia9.Basedoncurrentgrowthtrends,theYankeeGroupanticipatesthatby2010,wirelessdatashareoftotalARPUwillbe22.6%,translatingtoactualglobalindustryrevenueof$166billion10.

Wirelessdataisahugemarket,onewheresuccesswillbedrivenbytheefficienciesandcapabilitiesoftheunderlyingtechnologies.InformaSeniorResearchAnalystKesterMannconfirmed,"Datarevenuescontinuetobedrivenbytheongoingdeploymentofadvancedtechnologies,improvementsinhandsets,andglobalsubscriptiongrowth."

Fromadeviceperspective,TheShosteckGroup11projectsthefollowingsalesofWCDMAhandsets,includingWCDMA/EDGEhandsets:

2004:22million

2005:50million

2006:112million

2007:225million

2008:310million

AnalystfirmGartnerpredictsthatsalesofHSDPAhandsetswillreach2.1millionthisyearandwillincreaseto89.3millionby2009.12

6“WorldCellularInformationService,”InformaTelecoms&Media,September2006.

7“MobileBroadband:TheGlobalEvolutionofUMTS/HSPA—3GPPRelease7andBeyond,”3GAmericaswhitepaper,July2006.

8“U.S.WirelessDataMarket—MidYearUpdate2006,”ChetanSharma,

/midyearupdate06.htm

9InformaTelecom&Media'sWorldCellularInformationService,July2006.

10“GlobalWireless/MobilePremiumForecast,”YankeeGroupreport,November2005,?Copyright1997-2006.YankeeGroupResearchInc.Allrightsreserved.

11TheShosteckGroup,July2006.

12“Forecast:MobileTerminals,Worldwide,2000-2009(4Q05Update),”Gartner,January12,2006.

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ItisclearthatbothEDGEandUMTS/HSDPAaredominantwirelesstechnologies.Andpowerfuldatacapabilitiesandglobalpresencemeanthesetechnologieswilllikelycontinuetocapturemostoftheavailablewirelessdatamarket.

TechnologyCapabilitiesandMigration

TheEDGE/HSPA/LTEfamilyofdatatechnologiesprovidesever-increasingcapabilitiesthatsupportevermoredemandingapplications.GPRSandEDGE,nowavailableglobally,alreadymakeawealthofapplicationsfeasible,includingenterpriseapplications,messaging,e-mail,Webbrowsing,consumerapplications,andevensomemultimediaapplications.WithUMTSandHSDPA,usersareenjoyingvideophones,high-fidelitymusic,richermultimediaapplications,andefficientaccesstotheirenterpriseapplications.

Itisimportanttounderstandtheneedsenterprisesandconsumershavefortheseservices.Theobviousneedsarebroadcoverageandhighdatathroughput.Lessobviousneedsforusers,butascriticalforeffectiveapplicationperformance,arelowlatency,qualityofservice(QoS)control,andspectralefficiency.Spectralefficiency,inparticular,isofparamountconcern,asittranslatestohigheraveragethroughputs(andthusmoreresponsiveapplications)formoreusersactiveinacoveragearea.Thediscussionbelow,whichexamineseachtechnologyindividually,detailshowtheprogressionfromGPRStoHSPAthenLTEisoneofincreasedthroughput,enhancedsecurity,reducedlatency,improvedQoS,andincreasedspectralefficiency.

Itisalsohelpfultospecificallynotethethroughputrequirementsnecessaryfordifferentapplications:

Microbrowsing(e.g.,WirelessApplicationProtocol[WAP]):8to32kilobitspersecond(kbps)

Multimediamessaging:8to64kbps

Videotelephony:64to384kbps

GeneralpurposeWebbrowsing:32kbpstomorethan1Mbps

Enterpriseapplications,includinge-mail,databaseaccess,andVPNs:32kbpstomorethan1Mbps

Videoandaudiostreaming:32to384kbps

NotethatGPRSandEDGEalreadysatisfythedemandsofmanyapplications.WithHSPA,applicationsoperatefasterandtherangeofsupportedapplicationsexpandsevenfurther.

Underfavorableconditions,EDGEdeliverspeakuser-achievablethroughputratescloseto200kbpsandinitialdeploymentsofHSDPAdeliverpeakuser-achievabledownlinkthroughputratesofwellover1Mbps,easilymeetingthedemandsofmanyapplications.Latencyhaskeptimprovingaswell,withHSDPAnetworkstodayhavinground-triptimesaslowas70milliseconds(msec).Thecombinationoflowlatencyandhighthroughputtranslatestoabroadbandexperienceforusers,whereapplicationsareextremelyresponsive.(Thefinalsectionofthispaperquantifiestheperformanceofthevariouswirelesstechnologiesinconsiderabledetail.)

Inthissection,weconsiderdifferenttechnicalapproachesforwirelessaswellastheparallelevolutionof3GPPtechnologiesandthenprovidedetailsonGPRS/EDGE,UMTS/HSPA,LTE,andsupportingtechnologiessuchasIMS.

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TechnicalApproaches(TDMA,CDMA,OFDM)

ConsiderablediscussionintheindustryhasfocusedontherelativebenefitsofTimeDivisionMultipleAccess(TDMA),CodeDivisionMultipleAccess(CDMA),andmorerecentlyOrthogonalFrequencyDivisionMultiplexing(OFDM.)Manytimes,onetechnologyortheotherispositionedashavingfundamentaladvantagesoveranother.However,anyofthesethreeapproaches,whenfullyoptimized,caneffectivelymatchthecapabilitiesofanyother.GSMisacaseinpoint.Throughinnovationssuchasfrequencyhopping,theAdaptiveMultiRate(AMR)vocoderforvoice,andEDGEforoptimizationofdataperformance,GSMisabletoeffectivelycompetewiththecapacityanddatathroughputofCDMA2000OneCarrierRadioTransmissionTechnology(1xRTT).

DespitetheevolutionofTDMAcapabilities,thecellularindustryhasgenerallyadoptedCDMAfor3Gnetworkingtechnology.AlthoughtherearesomesignificantdifferencesbetweenCDMA2000andWCDMA/HSDPA,suchaschannelbandwidthsandchiprates,bothtechnologiesusemanyofthesametechniquestoachieveroughlythesamedegreeofspectralefficiencyandexpectedtypicalperformance.Techniquesincludeefficientschedulers,higherordermodulation,Turbocodes,andadaptivemodulationandcoding.

Today,peopleareaskingwhetherOFDMprovidesanyinherentadvantageoverTDMAorCDMA.Forsystemsemployinglessthan10MHzofbandwidth,theanswerislargelyno.ThefundamentaladvantageofOFDMisthatbecauseittransmitsmutuallyorthogonalsubchannelsatalowersymbolrate,itelegantlyaddressestheproblemofintersymbolinterferenceinducedbymultipathandgreatlysimplifieschannelequalization.Assuch,OFDMsystems—assumingtheyemployalltheotherstandardtechniquesfor