nsn high capacity mobile broadband for mass events white paper
TRANSCRIPT
-
High Capacity Mobile Broadband for Mass Events
NSN White paper October 2013
-
nsn.comPage 2
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
-
nsn.comPage 3
1. IntroductionThepopularityofsmartphonescreateshugecapacityrequirementsfornetworksduringmasseventsinstadiumshousingupto100,000peopleoracrosslargerurbanareaswithuptoamillionormoreparticipants.Atsuchevents,largenumbersofpeopleusetheirsmartphonestosharepicturesandexperiencesanddownloadinformation.Thisbehaviorcreatestrafficprofilesthatdifferfromthosetypicallyseeninthenetwork,withhigheruplinktrafficandmorefrequentpackettransmission.
Planningfortheseeventsmustconsidertheuplinkcapacityandcontrolplanedimensioning.NetworkRFplanninginlargeopenareascreatesfurtherchallengesintermsofinter-cellinterference.
ThesechallengesandtheNokiaSolutionsandNetworks(NSN)solutionsarediscussedinthiswhitepaper.
NSNisexperiencedinprovidinghighcapacitysolutionsinmassevents.Recentexamplesincludemorethan25GigabytesofdataperhourduringahugesportseventintheUK,morethan150GigabytesofdataperhourinaKoreanfireworksfestival,andmorethan100Terabytesofdataduringthe6-dayHajjpilgrimage.Inallcases,excellentenduserperformancewasachieved.
Figure1.Examplemassevents
-
nsn.comPage 4
2. TrafficProfilesinMassEventsTrafficprofilesinmobilenetworksareusuallydominatedbydownlinktraffic,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
-
nsn.comPage 5
3. Liquid Radio Software Suites: HSPA+Enhancements
HSPA+hasturnedouttobethemostsuccessfulandwidespreadmobilebroadbandsolutionglobally.HSPA+offersattractiveenduserdatarates,highspectralefficiencyfordataandgoodvoicecapacityinlivenetworks.
However,masseventsstillrequirespecialattentionforoptimizedperformance.Duringanevent,HSPA+performancecanbelimitedbyinterferencefromRandomAccessChannel(RACH)andfromDedicatedPhysicalControlChannel(DPCCH)inboththeuplinkanddownlink.Thetransmissiontimeoftheuserdataisjustafewmillisecondsforsmallpacketsizes,whileDPCCHrunsforafewseconds,seeNSNWhitepaperHSPA+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
-
nsn.comPage 6
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
-
nsn.comPage 7
4. LTERequirementsBeingpacket-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
-
nsn.comPage 8
5. RFPlanningandOptimizationThemasseventcapacitydependsheavilyonthenumberofcellsandonnetworkRFplanning.Morecellscan,intheory,providemorecapacity,butifcelloverlappingincreases,theadditionalcellsmayonlyincreaseinterferencelevels.Therefore,thecelldominanceareasneedtobeplannedcarefullytoavoidunnecessarycelloverlapping.
Practicalsolutionsincludeselectionofantennalocationsandselectionofantennadowntilts.However,physicalantennalocationsmaybelimitedinmassevents,soanactiveantenna,suchastheNSNFlexiMultiradioAntennaSystem,canbeusedtobringflexibilitytobeamsteering.TheactiveantennaincludessmallRFelementsinsidetheantennawhichmakesthesitesolutioncompactandbringsflexiblebeamformingcapability.Figure6showstheactiveantennaconcept.
Figure6.Activeantennaforverticalsectorization
-
nsn.comPage 9
6. DistributedAntennaSystem(DAS)DASisbecominganincreasingpopularwaytoaddressboththecoverageandthecapacityneedsofmassevents.
TheDASinfrastructureistypicallypartofthevenueandisprovidedbythevenuesowner.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
-
nsn.comPage 10
Figure8.Stadiumwith12cellseachwithsixantennas
-
nsn.comPage 11
7. SmallCellsMasseventcapacitycanberaisedefficientlybymicroandpicobasestations.Althoughpicobasestationsaresmall,theydoprovidehighcapacitytosupportmassevents(allowinghundredsofuserstobeconnectedtoasinglebasestation),andareavailableforoutdoorandpublic-spacedeployment.Thiscontrastswithenterprisefemtoaccesspoints,forexample,whicharedesignedforenterpriseusecases,bothfromenvironmentalaspects,butalsofromacapacitypointofview.
Picobasestationsshouldbedesignedaroundfeatureparitytomacrocellstodeliverconsistentenduserperformanceacrossdifferentcellsandinordertomakenetworkoptimizationandinterferencemanagementsimplebetweenmacroandsmallcells.Thepicobasestationssmallsizeandlightweightreducessiteandinfrastructurerequirementssignificantly,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
-
nsn.comPage 12
8. SmartWi-FiCapacityTomeetgrowingdemandforadditionalcapacityanddataservices,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-Finetworksaccordingtotheoperatorsbusinessstrategy.
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 trac value chain and control over user experience for Wi-Fi access
Harmonized trac handling with unied core network for mobile and Wi-Fi
By 2015 more than 90% of wireless trac will be data**
60-70% of trac 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
-
nsn.comPage 13
9. EnhancedMultimediaBroadcastMulticastServices(eMBMS)
EnhancedMultimediaBroadcastMulticastServices(eMBMS)usetheLTEnetworktosendthesamecontentsimultaneouslytoallusersinthecellcoveragearea.eMBMSiswellsuitedtothedeliveryofvideoorothercontentduringamasseventbecausemanyparticipantswouldliketoseethesamecontentfromgameorevent.ThecellsresourcescanbeadjusteddynamicallybetweeneMBMSandpoint-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
-
nsn.comPage 14
10. SummaryMasseventssethighrequirementsonmobilenetworks.Alargenumberofusersinasmallarea,relativelymoreuplinktraffic,hightransmissionfrequencyofsmallpacketscombinedwithchallengingRFplanning.NSNradionetworkshaveshownverygoodperformanceinmasseventsandtherearefurthersolutionsavailablein3GandinLTEtoincreasethecapacity-evenupto75xin3G.
NSNispushingthelimitsfurtherwithactiveantennasandefficientuseofdistributedantennasystems.Microandpicobasestationscanbeusedefficientlytoprovidehighcapacitywithsimpleinstallation,andenhancedlatertoaFlexiZonedeployment.Additionally,cellularnetworkcapacityiscomplementedbyWi-FioffloadingwiththeintroductionofreliableandhighWi-FiRFperformancewithintegrationofmobileandWi-Finetworksforthebestpossibleuserexperience.
-
nsn.comPage 15
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
-
Nokia Solutions and Networks P.O.Box1 FI-02022 Finland
Visitingaddress: Karaportti3,ESPOO,Finland Switchboard+358714004000
ProductcodeC401-00849-WP-201310-1-EN
2013NokiaSolutionsandNetworks.Allrightsreserved.
Public NSNisatrademarkofNokiaSolutionsandNetworks.NokiaisaregisteredtrademarkofNokiaCorporation.Otherproductnamesmentionedinthisdocumentmaybetrademarksoftheirrespectiveowners,andtheyarementionedforidentificationpurposesonly.
nsn.com