High Capacity Mobile Broadband for Mass Events

NSN White paper October 2013

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CONTENTS

1. Introduction 3

2. TrafficProfilesinMassEvents 4

3. LiquidRadioSoftwareSuites:HSPA+Enhancements 5

4. LTERequirements 7

5. RFPlanningandOptimization 8

6. DistributedAntennaSystem(DAS) 9

7. SmallCells 11

8. SmartWi-FiCapacity 12

9. EnhancedMultimediaBroadcastMulticastServices(eMBMS) 13

10. Summary 14

11. Abbreviations 15

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1. IntroductionThepopularityofsmartphonescreateshugecapacityrequirementsfornetworksduringmasseventsinstadiumshousingupto100,000peopleoracrosslargerurbanareaswithuptoamillionormoreparticipants.Atsuchevents,largenumbersofpeopleusetheirsmartphonestosharepicturesandexperiencesanddownloadinformation.Thisbehaviorcreatestrafficprofilesthatdifferfromthosetypicallyseeninthenetwork,withhigheruplinktrafficandmorefrequentpackettransmission.

Planningfortheseeventsmustconsidertheuplinkcapacityandcontrolplanedimensioning.NetworkRFplanninginlargeopenareascreatesfurtherchallengesintermsofinter-cellinterference.

ThesechallengesandtheNokiaSolutionsandNetworks(NSN)solutionsarediscussedinthiswhitepaper.

NSNisexperiencedinprovidinghighcapacitysolutionsinmassevents.Recentexamplesincludemorethan25GigabytesofdataperhourduringahugesportseventintheUK,morethan150GigabytesofdataperhourinaKoreanfireworksfestival,andmorethan100Terabytesofdataduringthe6-dayHajjpilgrimage.Inallcases,excellentenduserperformancewasachieved.

Figure1.Examplemassevents

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2.  Traffic Profiles in Mass EventsTrafficprofilesinmobilenetworksareusuallydominatedbydownlinktraffic,whichisuptotentimesgreaterthanuplinktrafficvolumes.Downlinktrafficiscreatedmainlybystreamingtrafficfromsmartphones,laptopsandtablets.

Thetrafficprofileduringmassevents,however,tendstobedifferent:

• Relativelyhigheruplinktrafficiscreatedbyparticipantssharingpicturesfromtheevent,forexampleinFacebook.Theuplinkcanevenexperiencemoretrafficthanisseeninthedownlink.Streamingisnottypicallyusedduringmasseventsunlesstherearevenuespecificservices,likeareplayvideoservicetoshowgoalsortouchdowns.Figure2showsthepotentialasymmetry.

• Theaveragedatavolumeperchannelallocationissmallerinmasseventsbecausethetrafficisgeneratedbysmartphonesinsteadoflaptopsortablets.Figure3showsanexampledatavolumeperchannelallocation.Eachchannelallocationalsoconsistsofseveralsmallerpacketswithaveragesizesofjust120bytesintheuplinkand840bytesinthedownlinkasmeasuredinlivenetworks.

Network wide Mass events

250

200

150

100

50

0

Data volume (kB)

Figure3.Datavolumeperchannelallocation

Figure2.Trafficasymmetrybetweendownlinkanduplink

2100 MHz

2100 MHz

Handoversbetween

LTE and HSPA

2100 MHz

10x

Global Mobile Traffic Forecast

Annu

al tr

affic (

PB)

25,00

20,00

15,000

10,00

5,000

50,00

45,00

40,00

35,000

30,000

02010 2011 2012 2013 2014 2015

Mobile voice (16kbps) Mobile tablet Mobile laptop Mobile handheld

Mobile Internet Traffic (ExaByte/year)

25

20

15

10

5

02010 2011 2012 2013 2014 2015

Mobile Laptop

Max subscribers per cell with 60 s packet period

5,000

4,500

4,000

3,000

3,000

2,500

2,000

1,500

1,000

500

0

0.5 1.0 2.0 4.0 8.0 16.0 32.0 64.0

Packet size [kB]

Release 6

Release 7 (CPC)

Release 8 (HS-RACH)

Network wide Mass events

8

7

6

5

4

3

2

1

0

Asymmetry downlink vs uplink

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3. Liquid Radio Software Suites: HSPA+ Enhancements

HSPA+hasturnedouttobethemostsuccessfulandwidespreadmobilebroadbandsolutionglobally.HSPA+offersattractiveenduserdatarates,highspectralefficiencyfordataandgoodvoicecapacityinlivenetworks.

However,masseventsstillrequirespecialattentionforoptimizedperformance.Duringanevent,HSPA+performancecanbelimitedbyinterferencefromRandomAccessChannel(RACH)andfromDedicatedPhysicalControlChannel(DPCCH)inboththeuplinkanddownlink.Thetransmissiontimeoftheuserdataisjustafewmillisecondsforsmallpacketsizes,whileDPCCHrunsforafewseconds,seeNSNWhitepaper“HSPA+BoostersforMultifoldPerformance”.ThemainsolutionsforminimizinguplinkinterferenceareNSNMassEventHandler(MEH),andNSNLiquidRadioSoftwareSuitesoffering featuressuchasContinuousPacketConnectivity(CPC),HighSpeedRACH(HS-RACH),4-branchuplinkreception(4RX)andInterferenceCancellation(IC).

Thebenefitsofthesesolutionsinclude:

• MEH:dynamicadjustmentofcelllevelparameterswhencongestionisidentified

• CPC:discontinuousDPCCHtransmission

• HS-RACH:moreefficientcommonchanneltransmissionwithoutdedicatedchannelallocation

• 4RX:3dBlowerterminaltransmissionpower

• IC:cancellationofintra-cellinterference

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Combiningallthesesolutionsyieldsahugeimprovementinuplinkcapacityforsmallpackettransmission.Figure4illustratesthatthecapacitycanbeenhancedby50to75times.

Themainsolutionsforminimizingdownlinkinterferenceare:

• FractionalDPCH(F-DPCH)whichremovestheneedforanyRelease99channeltothereforeavoiddownlinkDPCCH

• HS-FACH,whichisthesameasHS-RACHbutforthedownlink

• MassEventHandler(MEH)whichdynamicallyallowsmorepowertobeusedforRelease99channelsifrequiredandthereforeavoidsrepetitiveattemptsandrejectionsforRelease99highpriorityservicessuchasvoice.

AlltheseHSPA+improvementsareavailablecommerciallyinnetworksandindevices(wheresupportisneeded)during2013.

CPC

HS-RACH

4RX

Interferencecancellation

Total

5x

5x

2x

1.5x

75x

4x

4x

2x

1.5x

50x

0.5 kBpacket size

1 kBpacket size

Figure4.UplinkcapacityincreasewhenusingNSNsolutionforuplinkinterferenceminimization

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4.  LTE RequirementsBeingpacket-based,LongTermEvolution(LTE)isinherentlywellsuitedtotheburstytransmissionofsmallpackets,althoughchallengesstillexistduringextrememassevents,suchascontrolplaneprocessingcapacity,RACHcapacityandinter-cellinterference.

Figure5showsanexamplelivenetworkwithhighlyloadedLTEbasestations.Thenetworkexperiencesupto60handoverspersecond,upto50EUTRANRadioAccessBearer(eRAB)setupspersecond,andupto40RadioResourceControl(RRC)setupspersecond.Thetotalnumberofallocationsoverthehourexceeds200,000perbasestation.Suchhighsignallingfrequencyrequireshighcontrolplanecapacityinthebasestation.NSNFlexiBaseStationisdesignedforhighcapacityinthecontrolanduserplanes.

PhysicallayerRandomAccessChannel(PRACH)collisionscanoccurin3GandLTE.IftwoterminalsselectthesamePRACHresource,unnecessarilyhighpowerisneededforthePhysicalUplinkSharedChannel(PUSCH),whichcausesmassiveinter-cellinterference.PRACHcapacityallocationandexpectedPRACHtrafficandcapacityrequestsonPRACHmustbemanagedproperlytoavoidcollisions.

2100 MHz

2100 MHz

Handoversbetween

LTE and HSPA

2100 MHz

10x

Global Mobile Traffic Forecast

Annu

al tr

affic (

PB)

25,00

20,00

15,000

10,00

5,000

50,00

45,00

40,00

35,000

30,000

02010 2011 2012 2013 2014 2015

Mobile voice (16kbps) Mobile tablet Mobile laptop Mobile handheld

Mobile Internet Traffic (ExaByte/year)

25

20

15

10

5

02010 2011 2012 2013 2014 2015

Mobile Laptop

Max subscribers per cell with 60 s packet period

5,000

4,500

4,000

3,000

3,000

2,500

2,000

1,500

1,000

500

0

0.5 1.0 2.0 4.0 8.0 16.0 32.0 64.0

Packet size [kB]

Release 6

Release 7 (CPC)

Release 8 (HS-RACH)

Handovers eRAB setups RRC setups

70

60

50

40

30

20

10

Control plane actions per base station per second

0

Figure5.ControlplanefrequenciesinhighlyloadedLTEbasestations

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5.  RF Planning and OptimizationThemasseventcapacitydependsheavilyonthenumberofcellsandonnetworkRFplanning.Morecellscan,intheory,providemorecapacity,butifcelloverlappingincreases,theadditionalcellsmayonlyincreaseinterferencelevels.Therefore,thecelldominanceareasneedtobeplannedcarefullytoavoidunnecessarycelloverlapping.

Practicalsolutionsincludeselectionofantennalocationsandselectionofantennadowntilts.However,physicalantennalocationsmaybelimitedinmassevents,soanactiveantenna,suchastheNSNFlexiMultiradioAntennaSystem,canbeusedtobringflexibilitytobeamsteering.TheactiveantennaincludessmallRFelementsinsidetheantennawhichmakesthesitesolutioncompactandbringsflexiblebeamformingcapability.Figure6showstheactiveantennaconcept.

Figure6.Activeantennaforverticalsectorization

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6.  Distributed Antenna System (DAS)DASisbecominganincreasingpopularwaytoaddressboththecoverageandthecapacityneedsofmassevents.

TheDASinfrastructureistypicallypartofthevenueandisprovidedbythevenue’sowner.Itisabletohostmultiplewirelessoperatorswhopayafee.Itisalsoabletohostmultipletechnologies.

AnoperatorusestheDASbyattachingitsRFHeadantennaportstotheDASnodeasshowninFigure7.TheDASNetAggregatorcombinesmultipleoperatorsandRATsthroughamixedactive/passivenetworkthatprovidesanalogtofiberconversionanddistributionwithinDASequipment.Figure8showsatypicalstadiumwith12LTEandWCDMAcellseachwithsixantennas(twoineachtier.)Theantennasitesareshownastrianglesandrounddotsareuserpositions,whiletheothercolorsdenotethefirstcellattachment.ThesubsequentplotistheuserCarriertoInterferenceNoiseRatio(CINR)wheretheDASantennalocationsbecomevisible.

Tx/Rx

Coax Fiber

Tx/Rx

Tx/Rx To other SPs

Passive DAS

Passive DAS

SP RF Net SP RF Net eNB -LP Head

DAS RF Head

DAS RF Head

DAS RF Head

DAS RF Head

DAS RF Head

eNB -LP Head

DAS Net Aggregator DAS Net Aggregator DAS Net Aggregator

Flexi MultiradioBase Station

Flexi MultiradioBase Station

Flexi MultiradioBase Station

Flexi MultiradioBase Station

Band B eNBRF Head

Band A eNB RF Head

Band B eNBRF Head

Band A eNB RF Head

Figure7.DistributedAntennaSystem

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Figure8.Stadiumwith12cellseachwithsixantennas

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7.  Small CellsMasseventcapacitycanberaisedefficientlybymicroandpicobasestations.Althoughpicobasestationsaresmall,theydoprovidehighcapacitytosupportmassevents(allowinghundredsofuserstobeconnectedtoasinglebasestation),andareavailableforoutdoorandpublic-spacedeployment.Thiscontrastswithenterprisefemtoaccesspoints,forexample,whicharedesignedforenterpriseusecases,bothfromenvironmentalaspects,butalsofromacapacitypointofview.

Picobasestationsshouldbedesignedaroundfeatureparitytomacrocellstodeliverconsistentenduserperformanceacrossdifferentcellsandinordertomakenetworkoptimizationandinterferencemanagementsimplebetweenmacroandsmallcells.Thepicobasestation’ssmallsizeandlightweightreducessiteandinfrastructurerequirementssignificantly,anditslargecapacitymakesittherightchoiceforhandlingmasseventcapacity.

Smallbasestationsarealsovisuallydiscreteandcanbecamouflagedeasilytoblendwiththesurroundingenvironment,makingthemvirtuallyunnoticeableasabasestation.AnexamplesmallcellproductisshowninFigure9:NSNFlexiLiteBaseStationwithavolumeof10litersandweightof10kilograms,offeringoutputpowerof10wattsforWCDMA/HSPA.

Figure10showsaNSNFlexiZoneMicroBaseStationwithLTEcapability,andwhichhasasizeofonly5litersandweighsjust5kilograms,butoffersanoutputpowerof5watts.Meanwhile,theNSNFlexiZonePicoBaseStationwith1wattoutputpowerandoptionalWi-FicouldformthebaseofaverydensedeploymentinmasseventlocationsbycombiningthecapacityofLTEandWi-Fiwithaverycloselyspaceddeploymentgrid.

FlexiZoneenableshotspotstobeevolvedintoahotzonecoveredbyaclusterofsmallLTEbasestationsconnectedtoalocalcontroller,forservinghighestcapacityrequirements.FlexiZone alsominimizesthebackhaulload,optimizesradioresourcemanagementandsimplifiesnetworkoperation.Formoredetails,seehttp://www.nsn.com/sites/default/files/document/flexizone_brochure_120124.pdf.

Figure9.NSNFlexiLitehighcapacitysmallbasestation

Figure10.NSNFlexiZonemicrohighcapacitysmallbasestation

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8.  Smart Wi-Fi CapacityTomeetgrowingdemandforadditionalcapacityanddataservices,Wi-Fiisusedincreasinglyasacosteffectivemeanstoaddcapacityandtocomplementavailablemobilenetworks.Wi-Fihasbecomeastandardfeatureinsmartphonesandtablets,providingmasseventorganizerswithanopportunitytotakeadvantageofthisunlicensedspectrumtoimprovetheuserexperienceandoffervenue-specificapplications. TherecentlylaunchedNSNSmartWi-Fiisanend-to-endsolutionforbuilding,optimizingandcontrollingWi-Finetworks.

Theoverwhelmingnumberofusersandbusinesscriticalapplications,liketicketing,canintroduceasignificantstressontheavailableWi-Finetwork,requiringcarefulWi-Finetworkplanning.Useofthe5GHzbandprovideswiderfrequencyspectrumandmorebandwidth,aswellasahighernumberofavailablechannels,allowingmoreAccessPoints(APs)tobedeployedtomeetthecapacitydemandwithoutinterference.The2.4GHzbandwillalsoneedtobesupportedandbecausethebandhasthreenon-overlappingchannels(1,6,11),reusingthosechannelsistheprimaryalternative.

Asmostdevicesinamasseventareexpectedtobesmartphonessupporting3G/LTEandWi-Fiaccesses,theuseofallavailablenetworksshouldbeconsideredforachievingthebestoveralluserexperience.TheSmartWi-FisolutionintegratesmobileandWi-Finetworksforaseamlessexperiencebysupporting3GlikeusabilityandsecurityforWi-FiaccessandharmonizingtraffichandlingacrossmobileandWi-Finetworks.

Inaddition,SmartWi-Fibalancestrafficacrossavailablemobileand Wi-FinetworksbycontrollingwhenandwhereuserdevicesutilizemobileandWi-Finetworksaccordingtotheoperator’sbusinessstrategy.

Solution

Internet services

Operator services

Enables Wi-Fi networks to deliver an improved mobile broadband experience without costly network expansion and by using the existing network elements

High performance indoor connections

Faster data speeds

3G like Wi-Fi usability and security

Increased customer satisfaction

Retain position in traffic value chain and control over user experience for Wi-Fi access

Harmonized traffic handling with unified core network for mobile and Wi-Fi

By 2015 more than 90% of wireless traffic will be data**

60-70% of traffic is estimated to be generated indoors *

How to manage user experience and network utilization

* ABI Research ** Analysis Mason

Internet

Mobile Core

Figure11.NSNSmartWi-FisolutionturnsWi-Finetworksintoseamlessextensionsofthemobilenetwork

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9.   Enhanced Multimedia Broadcast Multicast Services (eMBMS)

EnhancedMultimediaBroadcastMulticastServices(eMBMS)usetheLTEnetworktosendthesamecontentsimultaneouslytoallusersinthecellcoveragearea.eMBMSiswellsuitedtothedeliveryofvideoorothercontentduringamasseventbecausemanyparticipantswouldliketoseethesamecontentfromgameorevent.Thecell’sresourcescanbeadjusteddynamicallybetweeneMBMSandpoint-to-pointtransmissiondependingontheinstantaneousrequirements,whichallowsquickadaptationtothedifferentmasseventcases.

TheintroductionofeMBMScarriessomechallenges.First,eMBMSsupportisrequiredintheterminals.Currentterminalsdonot supporteMBMSanditwilltakesometimebeforegoodpenetration isachieved.SecondlyeMBMSasabroadcast/multicasttechnologydoesnotaddresschallengesfromincreasinguplinkcapacityrequirement-whichspecificallyinmasseventsmustbeaddressed(e.g.Facebookuserssharingcontent).Asathirdandgenerallyapplicableconsideration,eMBMSishardlyusefuloutsidemasseventssincemostpeoplewanttoseevideo-on-demandcontentratherthanlinearTVbroadcastcontent.Therefore,theeMBMSapplicationareamaybetoolimitedintheshorttermincurrentspectrumallocations.IfmoreUHFspectrumcouldbeusedforeMBMSandifterrestrialTVwasdeliveredovereMBMS,theapplicationareaswouldbemoreattractive.

Point-to-point

eMBMS

Cell resources

Figure12.DynamicsharingofresourcesbetweeneMBMSand point-to-point

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10.  SummaryMasseventssethighrequirementsonmobilenetworks.Alargenumberofusersinasmallarea,relativelymoreuplinktraffic,hightransmissionfrequencyofsmallpacketscombinedwithchallengingRFplanning.NSNradionetworkshaveshownverygoodperformanceinmasseventsandtherearefurthersolutionsavailablein3GandinLTEtoincreasethecapacity-evenupto75xin3G.

NSNispushingthelimitsfurtherwithactiveantennasandefficientuseofdistributedantennasystems.Microandpicobasestationscanbeusedefficientlytoprovidehighcapacitywithsimpleinstallation,andenhancedlatertoaFlexiZonedeployment.Additionally,cellularnetworkcapacityiscomplementedbyWi-FioffloadingwiththeintroductionofreliableandhighWi-FiRFperformancewithintegrationofmobileandWi-Finetworksforthebestpossibleuserexperience.

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11.  Abbreviations3GPP ThirdGenerationPartnershipProject

CINR CarriertoInterferenceNoiseRatio

CPC ContinuousPacketConnectivity

DAS DistributedAntennaSystem

DPCCH DedicatedPhysicalControlChannel

eMBMS EnhancedMultimediaBroadcastMulticastServices

eRAB EUTRANRadioAccessBearers

F-DPCH FractionalDPCH

HSPA HighSpeedPacketAccess

HS-FACH HighSpeedForwardAccessChannel

HS-RACH HighSpeedRACH

IC InterferenceCancellation

LTE LongTermEvolution

MEH MassEventHandler

PRACH PhysicallayerRandomAccessChannel

PUSCH PhysicalUplinkSharedChannel

RACH RandomAccessChannel

RAN RadioAccessNetwork

RF RadioFrequency

RRC RadioResourceControl

WLAN WirelessLocalAreaNetwork

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©2013NokiaSolutionsandNetworks.Allrightsreserved.

Public NSNisatrademarkofNokiaSolutionsandNetworks.NokiaisaregisteredtrademarkofNokiaCorporation.Otherproductnamesmentionedinthisdocumentmaybetrademarksoftheirrespectiveowners,andtheyarementionedforidentificationpurposesonly.

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