VoLTE-SRVCC基本原理與系統(tǒng)結構

IMS2G/3GVoLTE網(wǎng)絡架構LTEeNodeBSGWHLR/HSS

IMS-HSSHLRLTE-HSSPGWMMEPCRFGERAN/UTRANMSSSGSNMGWP-CSCFA-BGWI-CSCFS-CSCFTASUEMRFCMRFPIMS-MGWMGCFBGCFMRFPVoLTE網(wǎng)元列表網(wǎng)元名稱網(wǎng)元所屬域網(wǎng)元功能歸屬網(wǎng)元eNodeBLTE無線支持VoLTE專用承載，支持SRVCC功能eNodeBMMEEPC核心網(wǎng)支持SRVCC功能MMES/P-GWEPC核心網(wǎng)支持VoLTE專用承載S/P-GWPCRFEPC核心網(wǎng)支持Rx接口用于建立VoLTE專用承載PCRFMSS/eMSSR4核心網(wǎng)支持SRVCC功能MSSMGCF互通關口局設備支持IMS/R4話音互通MGCFIM-MGW互通關口局設備支持IMS/R4話音互通IM-MGWI-SBCIMS核心網(wǎng)媒體域用于IMS互通本次測試暫不需要BCFIMS核心網(wǎng)控制域控制BGF用于IMS媒體面P-CSCFBGFIMS核心網(wǎng)媒體域用于IMS媒體面連接，與BCF共同承擔SBC功能BGWP-CSCFIMS核心網(wǎng)控制域接入側IMS核心網(wǎng)控制網(wǎng)元P-CSCFI/S-CSCFIMS核心網(wǎng)控制域用戶歸屬域IMS核心網(wǎng)控制網(wǎng)元I/S-CSCFBGCFIMS核心網(wǎng)控制域IMS用戶呼叫其他網(wǎng)絡時的路由功能I/S-CSCFDRAIMS核心網(wǎng)控制域提供Diameter接口(如Cx/Dx/Sh/Rx)路由功能DRAENUMDNSIMS核心網(wǎng)控制域將E.164號碼翻譯為IMS用戶的IMPUENUMDNSVoLTE網(wǎng)元列表網(wǎng)元名稱網(wǎng)元所屬域網(wǎng)元功能歸屬網(wǎng)元TASIMS核心網(wǎng)業(yè)務域用于支持VoLTE話音以及補充業(yè)務TASMRFCIMS核心網(wǎng)業(yè)務域VoLTE話音服務器中錄音通知與混音控制功能TASMRFPIMS核心網(wǎng)業(yè)務域VoLTE話音服務器中錄音通知與混音媒體功能BGWIP-SM-GWIMS核心網(wǎng)業(yè)務域提供VoLTE與CS的短信互通TASIM-SSF(可選)IMS核心網(wǎng)業(yè)務域提供VoLTE與CS的智能網(wǎng)互通TASIMS-HSSBEIMS核心網(wǎng)數(shù)據(jù)域用于存儲IMS有關用戶數(shù)據(jù)

HSS-BEIMS-HSSFEIMS核心網(wǎng)數(shù)據(jù)域用于提供HSS到CSCF或者業(yè)務服務器的接口HSS-FESCC-ASIMS核心網(wǎng)業(yè)務域提供SRVCC錨定功能的業(yè)務服務器TASATCFIMS核心網(wǎng)控制域提供eSRVCC控制面功能P-CSCFATGWIMS核心網(wǎng)數(shù)據(jù)域提供eSRVCC媒體面功能BGWCGIMS核心網(wǎng)支持域提供IMS計費數(shù)據(jù)整合功能開通網(wǎng)關(可選)IMS核心網(wǎng)支持域提供HSS/TAS統(tǒng)一開通功能OSSIMS核心網(wǎng)支持域提供IMS網(wǎng)管Needtobeadded3GPPVoLTENetworkInterfaceInterfBetweenProtocolFunctionGmUE?P-CSCFSIPAspartofitisover-the-air,signalingcompressionisneededMwCSCF?CSCFSIPUsedforsessionsetup,maintenanceandteardownMrS-CSCF?MRFCSIPS-CSCFrequestformediaresourcesfromMRFCduringsessioncontrolMxS-CSCF?ALGSIPDestinationnetworkrequiresIPversioninter-workingMiS-CSCF?BGCFSIPCSbreakout:

S-CSCFtowardaCSdestinationnetworkMjBGCF?MGCFSIPCSbreakoutMkBGCF?BGCFSIPInter-PLMNIMSinter-workingISCAS?S-CSCFSIPForthecontroltransfertoaASfromS-CSCFCxI/S-CSCF?HSSDiameterI/S-CSCFobtainsandupdatesuserandserviceprofiledatafromHSSDxI/S-CSCF?SLFDiameterI/S-CSCFaskSLFtolocatetheHSSinmulti-HSSnetworkShAS?HSSDiameterAStoobtainandupdateuserandserviceprofiledatafromHSSRfAS/CSCF/MGCF?CDFDiameterForcreatingofflinechargingrecordsRoAS/CSCF/MGCF?OCSDiameterForon-linechargingandsession/servicecontrolRxP-CSCF?PCRFDiameterP-CSCFrequestresourcereservationGxPCRF?P-GWDiameterPolicyandChargingruletoPaCoMpMRFC?MRFPH.248ForcontrolmediaresourcesMnMGCF?IMS-MGWH.248ForcontrolmediaresourcesMbUE?IMS-MGW/MRFPRTPCarryIPpacketsofmediastreamUtUE?ASXCAPForUEapp.Clienttomanageservice-relateddatawithASSrMRFC?ASXCAPMTRFobtaininfoaboutmediafromASVoLTEbearerconceptVoicetraffic-QCI1SIPSignaling-QCI5Videotraffic–QCI2EPCeNBVoLTErequiresownIMSAPN:SIPsignalingalwaysusesaQCI=5bearerwithnon-GBRVoicetrafficalwaysusesadedicatedQCI=1bearerwithGBROtherIMSmedia-ifpresent,e.g.forRCS-useQCI=8/9mediawithnonGBRInternettrafficforanother(internet)APNUMDRBUMDRBAMDRBIMSAPNBesteffortdata-QCI9AMDRBInternetAPNotherIMSmedia-QCI8/9AMDRBQoSaspectsofE2EVoLTECallFlow(IR.92)ThomasHammannPhase5:UserDataandGBR/NoneGBRschedulingE-UTRANS-GWS1-UEPSDefaultBearerforIMSAPN(QCI5,e-RAB=5,EBI=5)EPSBearerforDefaultBearerforDataAPN(QCI9,e-RAB=6EBI=6)P-GWS5/S8RadioAccessBearerismappedtoGTPTunnel.TFTstoselecte-RABinULTFTstoselectBearer(EBI)inDLSIPTrafficNoneGBRBearerforSIPSignallingPriority9,PacketDelayBudget300msec,PacketErrorLossRate10-6

DataTrafficNoneGBRBearerforDataPriority1,PacketDelayBudget100msec,PacketErrorLossRate10-6EPSDedicatedBearer(QCI1,e-RAB=7,EBI=7)VoIPDataGBRBearerforVoIPDataPriority2,PacketDelayBudget100msec,PacketErrorLossRate10-22ePreconditionUlfSpangenbergerPrecondition:asetofconstraintsthatmustbefulfilledbeforetheuserisalerted(rfc3312)newSDPattributescurr(currentstatus),des(desiredstatus),conf(confirmationstatus)Offer/AnswermessageflowInitialINVITE(SDP)183SessionProgress(SDP)UPDATE(SDP)200OK(SDP)RABsetupARABsetupB180RingingA->BDelayringinguntilcurr=desforAABB->AInformmewhencurr=confA->Bcurr=conf=desIMSInviteProcedure–RxInterfaceUlfSpangenberger2eP-CSCFAS-CSCFAS-CSCFBP-CSCFBPCRFPCRFINVITE(SDP) IPaddress-A,port-A,orderedlistofsupportedcodecs,[bandwidth]180RINGING200OK(SDP) IPaddress-B,port-B,orderedlistofnegociatedcodecs,[bandwidth]ACKSAE-GWSAE-GWSetupdedicatedbearerwithQCI=1AccessAuthorization,AAR/AFlowdescriptor:UL/DLforRTP/RTCPBandwidth:UL/DLforRTP/RTCPCodeclistCallrouting(IMPU)UE-AUE-BPCRFforVoLTE2eElisabethKozielPGWPCRFCreateDedicatedBearerReqPCCRulesProvisioning(PCCRules,EventTriggers)GxRAACreateDedicatedBearerRespServicesP-CSCFSessionandmediainfoPGWdecidesbasedontheQCI/ARPpairwhetheranexistingbearercanbeusedorwhetheranewdedicatedbearerisneededforVoIP12345DefaultBearerforsignalingcreated0Gx_CCR-I,QCI=5,ARP=2,SessionId=1Rx_AAR:MediaComponenDescriptionGx_RAR:Charging-Rule-Install(Flow,Qos),SessionId=1RxAAAIR.92basedQoSmodel:IMSAPNisusedfortheIMStraffic,otherAPNfordatatrafficE2EVoLTECallFlow(IR.92)2ePhase1Attach/PrimaryDefaultBearerwithIMSAPN(QCI=5)Phase2SIPRegisterw/primaryDefaultBearer/2ndPDNconnectionforDataAPNPhase3InitiateVoIPcallusingPrimarydefaultbearerPhase4DedicatedBearerforVoIPDataPhase5UserDataandGBR/Non-GBRsheduleingPhase6ReleaseofVoIPcallanddedicatedbearerLTE/EPCPointofViewPhase1SIPRegisterPhase2SIPInvitePhase3SIPReleaseIMSPointofViewOption1CombinedEPS/IMSIcombinedEPS/IMSIattachUEbehaviourforIMSPSVoicepreferredwithCSVoiceassecondaryTS23.221Option2noncombinedEPS/IMSIattachXVoLTE呼叫流程VoLTEHandoverProcedures

SRVCCHandoverforVoicefromLTEto2G/3GCSIMS/VoIP/VoLTE

DomainCScoverageLTE/EPSDomain2G/3GCS&PSDomainS6aDUE

(A-Party)Gr/S6dUE

(A-Party)LTE

coverageGmCxISCSv/

SGsGxRxMwSingle

Radio

VoiceCall

Continuity

(SR-VCC)eNBSAE-GWMMEPCRFCSCF

(ofA-Party)HSS/

HLRMSC-SMGWTASBSC/RNCSGSNGGSNOtherOperatorsLTE

CellCSCF

(ofB-Party)SCC-ASUE

(B-Party)S1-US1-MMES11VoicepathwhentheA-PartyisinLTEVoicepathwhentheA-PartyisinCSSRVCCrelatedsignallingSignallinginterfacesMAPSIPInvite(STN-SR,SDP=MGW)0.Userplanebefore

SR-VCCHandover6.UserplaneafterSR-VCChandover4.TheSCCASinitiatesa

SIPRe-InvitetotheB-Party

toswitchtheUserPlane

fromPDN-GWtotheMGW5.TriggeredbytheSIPRe-Invite,theB-partyswitchestheUserPlanetotheMGW2.MMEtriggers“PStoCSHand-overRequest”toMSC-SincludingTargetCellID,STN-SR,etc.1.eNbinitiates

SR-VCCHandover3.TheMSC-SreservesCSradioresources

andinitiatesaSIPInvitetowardstheIMS(SCC-AS)usingtheSTN-SR.STN-SRSessionTransferNumberforSRVCC(staticconfiguredinHSS)->SCC-ASIMS/VoIP/VoLTE

DomainCScoverageLTE/EPSDomain2G/3GCS&PSDomainS6aDUE

(A-Party)Gr/S6dUE

(A-Party)LTE

coverageGmCxISCSv/

SGsGxRxMwSingle

Radio

VoiceCall

Continuity

(SR-VCC)SheNBSAE-GWMMEPCRFCSCF

(ofA-Party)HSS/

HLRMSC-SMGWTASBSC/RNCSGSNGGSNOtherOperatorsLTE

CellCSCF

(ofB-Party)SCC-ASUE

(B-Party)S1-US1-MMES11VoicepathwhentheA-PartyisinLTEVoicepathwhentheA-PartyisinCSSRVCCrelatedsignallingSignallinginterfacesMAPATGWATCFMGWP-GW0.Userplaneisbefore

SR-VCCHandover2.MMEtriggers“PStoCSHand-overRequest”toMSC-SincludingTargetCellID,STN-SR,etc.1.eNbinitiates

SR-VCCHandover6.UserplaneafterSR-VCChandover3.TheMSC-SreservesCSradioresources

andinitiatesaSIPInvitetowardstheATCFusingtheSTN-SR.5.SCC-ASisinformedfortheSRVCCHOwithoutthebearerchangeindication.SincethereisnoSDPupdate,no

SIPRe-InviteissenttotheB-Party.4.ATCFconfiguresATGWwithSDP=MGWwhichswitchesthebearerfromPDN-GW(LTE)totheMGW(CS)VoLTEHandoverProcedures

eSRVCCHandoverforVoicefromLTEto2G/3GCSSTN-SRSessionTransferNumberforSRVCC(updatedduringRegistration)->ATCFAMR簡介全稱AdaptiveMulti-Rate，自適應多速率編碼，主要用于移動設備的音頻，壓縮比比較大，但相對其他的壓縮格式質量比較差，由于多用于人聲，通話，效果還是很不錯的。1.AMR:又稱為AMR-NB，相對于下面的WB而言，語音帶寬范圍：300－3400Hz，8KHz抽樣2.AMR-WB:AMRWideBand，語音帶寬范圍：50－7000Hz16KHz抽樣“AMR-WB”全稱為“AdaptiveMulti-rate-Wideband”，即“自適應多速率寬帶編碼”，采樣頻率為16kHz，是一種同時被國際標準化組織ITU-T和3GPP采用的寬帶語音編碼標準，也稱為G722.2標準。AMR-WB提供語音帶寬范圍達到50～7000Hz，用戶可主觀感受到話音比以前更加自然、舒適和易于分辨。AMR-NBFrameTypeModeIndicationModeRequestFramecontent(AMRmode,comfortnoise,orother)000AMR4,75kbit/s111AMR5,15kbit/s222AMR5,90kbit/s333AMR6,70kbit/s(PDC-EFR)444AMR7,40kbit/s(TDMA-EFR)555AMR7,95kbit/s666AMR10,2kbit/s777AMR12,2kbit/s(GSM-EFR)8--AMRSID9--GSM-EFRSID10--TDMA-EFRSID11--PDC-EFRSID12-14--Forfutureuse15--NoData(Notransmission/Noreception)AMR

一共有16種編碼方式，

0-7對應8種不同的編碼方式，

8-15

用于噪音或者保留用。AMR-WBFrameTypeIndexModeIndicationModeRequestFramecontent(AMR-WBmode,comfortnoise,orother)000AMR-WB6.60kbit/s111AMR-WB8.85kbit/s222AMR-WB12.65kbit/s333AMR-WB14.25kbit/s444AMR-WB15.85kbit/s555AMR-WB18.25kbit/s666AMR-WB19.85kbit/s777AMR-WB23.05kbit/s888AMR-WB23.85kbit/s9--AMR-WBSID(ComfortNoiseFrame)10-13--Forfutureuse14--speechlost15--NoData(Notransmission/Noreception)

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時延和抖動時延：端到端包傳遞的時間ITUG.114規(guī)范建議，在傳輸語音流量時,單向語音包端到端延遲要低于150ms(對于國際長途呼叫,特別是衛(wèi)星傳輸時,可接受的單向延遲為300ms。如果超過300ms則通話的質量會變的讓人不能忍受。過多的包延遲可以引起通話聲音不清晰、不連貫或破碎。經(jīng)驗：大多數(shù)用戶察覺不到小于100毫秒的延遲，當延遲在100毫秒和300毫秒之間時，說話者可以察覺到對方回復的輕微停頓。這種停頓可以影響到通話雙方的交流。超過300毫秒，延遲就會很明顯，用戶開始互相等待對方的回復，通話過程變成類似對講機式的模式。而且較長的時延也會將回聲問題的影響放大。時延的產(chǎn)生因素編碼的處理：模擬形式的