AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
SimonFraserUniversity|SchoolofEngineeringScienceENSC894-G100:CommunicaBonNetworksProf.LjiljanaTrajkovic April,2017
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• MoBvaBon• LiteratureReview• OverviewofRelevantLTEComponents
– E-UTRANArchitecture– ElementsoftheHandoverProcess
• SimulaBonMethodology• Results• Discussion• FutureWork• References
OUTLINE
E-UTRAN:EvolvedUniversalTerrestrialRadioAccessNetwork
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• TheintegraBonofsmall-cellnetworknodeswithinaconvenBonalcellularnetworkprovidesapromisingsoluBontoincreaseoverallnetworkcapacity.
• Offloadingusersfromthemacro-cellBertothesmall-cellBerfreesbandwidthonthemacro-cellBerforothermoremobileusers.
• HandoverisakeycomponentofguaranteeingtheexpectedqualityofservicewhileeffecBvelymanagingresourceswithintheseheterogeneousnetworks.
MOTIVATION
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• Significantresearchandcommercialinterestindeploymentofsmall-cellsandopBmizaBonofhandoveralgorithms.
• MulBtudeofproposedhandoveralgorithmsexist.– MajorityrelyonweighBngfuncBonstoalterbehaviourofconvenBonal
receivedsignal–basedalgorithms.
• Driversare:– SelfOrganizingNetworks[1,2]
– Load/trafficmanagement[3,4]
• Challengesare:– Unpredictabilityofsmall-celldeployment[3,5]– IntegraBonwithexisBngnetworks[5,6]
LITERATUREREVIEW
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• eNBsareinterconnectedviaX2interface.
• eNBsconnecttoEPCviatheMMEandS-GWoverS1interface.
• LTEsupportsbothS1andX2interface–basedhandover.
E-UTRANARCHITECTURE
E-UTRAN:EvolvedUniversalTerrestrialRadioAccessNetwork MME:MobilityManagementEnBtyeNB:E-UTRANNodeB S-GW:ServingGatewayEPC:EvolvedPacketCore
FigurecourtesyofETSITS136300V9.4.0
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
1. ChannelMeasurement– UEmeasuresRSRPandRSSI(atleast).– RSRQcanbederivedfromreportedRSRPandRSSI:RSRQ=(NRB*RSRP)/RSSI
2. HandoverDecision– UEwillreportameasurementeventtotheservingeNBiftheappropriatecondiBonsaremet.
3. HandoverPreparaBon,ExecuBon&CompleBon– TunnelingofpacketsfromsourcetotargeteNB.– TargeteNBconnecBonsetup,sourceeNBconnecBonteardown.
ELEMENTSOFTHEHANDOVERPROCESS
eNB:E-UTRANNodeB RSRP:ReferenceSignalReceivedPowerUE:UserEquipment RSRQ:ReferenceSignalReceivedQualityRB:ResourceBlock RSSI:ReferenceSignalStrengthIndicator
SelectedMeasurementEvents
EventA2 Servingcell’sRSRQbecomesworsethanthreshold.
EventA3 Neighbouringcell’sRSRPbecomesoffsetbeqerthanservingcell.
EventA4 Neighbouringcell’sRSRQbecomesbeqerthanthreshold.
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• Usens-3LTEModuledevelopedbyLENAProject.• Installalocalizedsmall-cellnetworkwithinamacro-cell
hexagonalgridtopology.• AlleNBsareconnectedviaanX2interface,andareconnected
totheEPCthroughanS1interface.
SIMULATIONMETHODOLOGY
eNB:E-UTRANNodeB SINR:SignaltoInterference+NoiseRaBoEPC:EvolvedPacketCore
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
SIMULATIONMETHODOLOGY(conLnued)
RSRP:ReferenceSignalReceivedPower RSRQ:ReferenceSignalReceivedQuality
• EmployRSRPmeasurementandRSRQmeasurement–basedhandoveralgorithms.
• Analyzetheefficiencyofbothalgorithmsatoffloadingtrafficfromthemacro-cellBerwhileensuringacceptablequalityofservice.
• AnalyzeeffecBvecellradiiandcoverage.
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• A2/A4measurementevent–basedhandoveralgorithm.
RESULTS
High
threshold
Lowthreshold
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• A3measurementevent–basedhandoveralgorithm.
RESULTS(conLnued)
Lowoffset
Short,me-to-trigger
Highoffset
Long,me-to-trigger
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
RESULTS(conLnued)
TimeasServingTierisdefinedasthecumulaBveBmetheUEwasconnectedtotheassociatednetworkBer,expressedasapercentageofthetotalsimulaBonBme.CoverageAreaisdefinedasthesumoverallsmall-cellnodesoftheareaboundedbyanellipsefittoallenteringandexiBnghandoversforagivennodeasapercentageoftheallowedrangeofUEmobility.
NetworkTier Link Avg.Delay(ms)
Avg.Throughput(Mbps) PacketLoss TimeasServing
Tier CoverageArea
Small-cell UL 5.63 8.43 0.03%62.02% ~47%
DL 35.54 8.27 1.84%
Macro-cell UL 5.66 8.42 0.09%37.98%
DL 81.68 8.19 2.83%
Small-cell UL 5.67 8.43 0.03%59.18% ~51%
DL 42.49 8.18 3.01%
Macro-cell UL 5.72 8.42 0.07%40.82%
DL 95.43 8.02 4.85%
Small-cell UL 5.66 8.43 0.03%61.77% ~35%
DL 50.21 7.99 2.67%
Macro-cell UL 5.70 8.42 0.12%38.23%
DL 92.38 8.04 3.66%
Small-cell UL 5.80 8.42 0.07%62.52% ~55%
DL 50.21 7.99 5.19%
Macro-cell UL 5.73 8.42 0.08%37.48%
DL 92.38 8.04 4.70%
A2/A4
High
A2/A4
Low
A3
Low/Short
A3
High/Long
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• HighA2/A4thresholdschemeshowsbest(byasmallmargin)small-cellandmacro-celldownlinkperformance.Alsoshowssmallestcoveragearea.
• HighA3offset,longBme-to-triggerschemeshowsworst(byasmallmargin)small-celluplinkperformance.Alsoshowslargestcoveragearea.
• HighA2/A4thresholdandhighA3offset,longBme-to-triggerschemesshowmosteffecBveatoffloadingusersfrommacro-cellBer.
DISCUSSION
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
• ExaminetheeffectsonhandoverperformanceofRSRPandRSRQ–basedalgorithmsbyincreasingUEandsmall-celldensity.
• ExaminetheperformanceoffrequencyreuseschemesonRSRPandRSRQ–basedhandoverinheterogeneousnetworks.
• ExaminetheperformanceofweighBnghandoveralgorithmswithfactorsderivedfromaddiBonalmeasurements.
FUTUREWORK
RSRP ReferenceSignalReceivedPower RSRQ ReferenceSignalReceivedQuality
AnAnalysisofHandoverPerformanceinHeterogeneousLTENetworks
NicholasWooster
[1]M.Song,S.MoonandS.Han,“Self-opBmizaBonofhandoverparametersfordynamicsmall-cellnetworks,”WirelessCommunica,onsandMobileCompu,ng,vol.15,no.11,pp.1497-1517,Aug.2015.[2]O.Østerbø,O.Grøndalen,“BenefitsofSelf-OrganizingNetworks(SON)forMobileOperators,”JournalofComputerNetworksandCommunica,ons,vol.2012,Sept.2015.[3]Y.Li,B.CaoandC.Wang,“HandoverSchemesinHeterogeneousLTENetworks:ChallengesandOpportuniBes,”IEEEWirelessCommunica,ons,vol.23,iss.2,pp.112-117,May2016.[4]J.RuizAvilés,M.TorilandS.Luna-Ramírez,“AFemtocelllocaBonstrategyforimprovingadapBvetrafficsharinginheterogeneousLTEnetworks,”JournalonWirelessCommunica,onsandNetworking,vol.15,no.38,Dec.2015.[5]G.Gódoretal.,“AsurveyofhandovermanagementinLTE-basedmulB-Berfemtocellnetworks:Requirements,challengesandsoluBons,”ComputerNetworks,vol.76,pp.17-41,Jan.2015.[6]D.Xenakisetal.,“MobilityManagementforFemtocellsinLTE-Advanced:KeyAspectsandSurveyofHandoverDecisionAlgorithms,”IEEECommunica,onsSurveys&Tutorials,vol.16,pp.64-91,Jul.2013.
REFERENCES
