UMTS Core Network - unipa.it

1 umts umts CoreCoreNetworkNetworkV. Mancuso, I. TinnirelloUMTS umts CoreCoreNetworkNetworkGSM/GPRS core networkRadio access networkBSSPSTN, ISDNBTSBSCMSCVLRGMSCHLRMSGSM/GPRS NetworkGSM/GPRS Network ArchitectureArchitectureV. Mancuso, I. TinnirellodatabaseIP BackboneInternetPSTN, ISDNBTSSGSNAuCEIRGGSNPCUCore Network (GSM/GPRS-based)Radio access networkUTRANUEIu CSIurUuPSTNBSRNCMSCVLRGMSCHLRIub3 GPP Rel. 99 Network Architecture3 GPP Rel. 99 Network ArchitectureV. Mancuso, I. TinnirelloIurIubUuGnIu PSdatabaseIP BackboneInternetBSRNCSGSNAuCEIRGGSNR adio access networkUTRANUEIurUuBSRNCIub2G => 3G MS => UE (User Equipment), often also called (user) terminal New air (radio) interface based on WCDMA access technology3 GPP 3 GPP RelRel.

2 99 Network architecture . 99 Network ArchitectureV. Mancuso, I. TinnirelloIurIubUuBSRNCNew RAN architecture (Iur interface is available for soft handover,BSC => RNC) core Network (GSM/GPRS-based)Iu CSPSTNMSCVLRGMSCHLRC hanges in the core Network :MSC is upgraded to 3G MSCSGSN is upgraded to 3G 3 GPP Rel. 99 Network Architecture3 GPP Rel. 99 Network ArchitectureV. Mancuso, I. TinnirelloGnIu PSIP BackboneInternetSGSNAuCEIRGGSNSGSN is upgraded to 3G SGSNGMSC and GGSN remain the sameAuC is upgraded (more security features in 3G) Circuit Switched (CS) core networkUTRAN( umts Terrestrial Radio Access Network )PSTNMSC ServerGMSC ServerSGWSGW3 GPP Network Architecture3 GPP Network ArchitectureV.

3 Mancuso, I. TinnirelloPSTNNew option in :GERAN(GSM and EDGE Radio Access Network )PS core as in Rel. 99 SGWMGWSGWMGWC ircuit Switched (CS) core networkPSTNMSC ServerGMSC ServerSGWSGWMSC Server takes care of call control signallingThe user connections are set up via MGW (Media GateWay) Lower layer protocol 3 GPP Network Architecture3 GPP Network ArchitectureV. Mancuso, I. TinnirelloPSTNPS core as in Rel. 99 SGWMGWSGWMGW Lower layer protocol conversion in SGW (Signalling GateWay)RANAP / ISUPSS7 MTPIP SigtranCS corePSTNMGWHSSIMS (IP Multimedia UTRAN( umts Terrestrial Radio Access Network )New core Network part:3 GPP Network Architecture3 GPP Network ArchitectureV.)

4 Mancuso, I. TinnirelloSGSNGGSNI nternetHSSM ultimedia System)PS coreGERAN(GSM and EDGE Radio Access Network )CS corePSTNI nternet / other IMSHSSThe IMS can establish multimedia sessions (using IP transport) via PS core between UE and Internet (or another IMS)IMS (IP Multimedia MGW3 GPP Network Architecture3 GPP Network ArchitectureV. Mancuso, I. TinnirelloSGSNGGSNI nternet / other IMSHSSPS coreCall/session control using SIP (Session Initiating Protocol)Interworking with the PSTN may be required for some time.

5 Multimedia System)Service providerService providerContent providerContent providerNew Service ConceptNew Service ConceptV. Mancuso, I. TinnirelloEnd userEnd userCarrier providerall want to make profitOSA is being standardised, so that services provided by different service/content providers can be created and seamlessly integrated into the 3G Network (this is the meaning of open architecture ) OSA means in practice:OSA (Open Services architecture /Access)OSA (Open Services architecture /Access)V. Mancuso, I. Tinnirello3G networkAPIAPIAPIS ervice Creation Environment (SCE)API = Application Programming Interface (Standardised)CAMEL (Customised Applications for Mobile Network Enhanced Logic) is a set of IN (intelligent Network ) type functions and procedures that make operator-specific IN services available to subscribers who roam outside their home Network .

6 CAMEL = IN technology + global mobilityCAMEL (2G & 3G)CAMEL (2G & 3G)V. Mancuso, I. TinnirelloCAMEL Service Environment (CSE) is a logical entity in the subscriber s home Network which processes IN related proceduresCSE SCP in home networkThe IMSThe IMSV. Mancuso, I. TinnirelloThe IP Multimedia SubsystemVincenzo Mancuso, PhDThe IMSThe IMS The Third generation networks aimto mergetwo most valuable resources in communicationtechnology, along with local PSTN networks Cellular Networks The InternetV. Mancuso, I.

7 Tinnirello Use packet switching, IP TheIP Multimedia Subsystem or IMSis the solution to integrate allthe services that the internet provides with the cellular and othernetworks Triple Play: coordination of voice, video and dataIMS ValueIMS Value--added servicesadded services IMS also can provide integratedservice to the user Third party developed services can be provided byoperators, thus developing value-added services Appropriatechargingformultimediasessions ,V. Mancuso, I. Tinnirello Appropriatechargingformultimediasessions ,according to the content and the service offeredIMS Service IntegrationIMS Service Integration ProblemStatement:variousnetworks providing services have a vertical infrastructure no horizontal links between networksV.

8 Mancuso, I. Tinnirello The challenge:tointegratethesenetworks and tocreate newapplicationsthat would provideservicetonextgenerationnetworksCo mponent #1: the media Component #1: the media transporttransport After many other services, introduction of real time voice/video on Internet The 1stproblem is easy: how to transmit voice/video?IP packetsV. Mancuso, I. Tinnirello RTP (Real-Time Protocol) is a protocol which transports an encoded multimedia stream as pieces, with a timestamp on each piece, and sends them using UDP/IP Any encoding is permitted for voice/video with a Codec: MP3, ACC, MPEG4, Several streams (voice+video) can be sent in parallel with the same timestamp The timestamp is used by the receiver to play the voice/video in a regular way for quality RTP is the media transportCodecRTPUDPIPC omponent #2: session initiationComponent #2.

9 Session initiation The 2ndproblem is more difficult: how to initiate the call? how to know the IP-address of the called phone? It is necessary to have a table which translates a symbolic name Betty into an IP addressRegistration of Betty s phone and addressV. Mancuso, I. Tinnirellosymbolic name Betty into an IP address Each time a terminal service is put on, it must notify its presence to update the table So, thanks to an access to this table, it is possible to make the address resolution : name -> IP address The control of the address table creates a tough of John s phone and addressWhy IMS?

10 Why IMS?Solutions to make the address resolutionsSolutions to make the address resolutionsMSN, Yahoo, AOL have designed a calling architecture hyper-centralized: 1 table worldwide, only 1 operatorSkype promotes a hyper-decentralized architecture : The introduction and development of solution like Skype is highly significant V. Mancuso, I. Tinnirellodecentralized architecture : 1 table per terminal with peer-to-peer update between terminalsas it alters the notion of telecommunications operators by making the process fully electronic IDATE - ART, 2004 Operators dislike such approaches, so they push a way very similar to e-mail: centralization per domain.