Policy and Regulatory Requirements for Future Mobile Networks
Policy and Regulatory Requirements for Future Mobile Networks June 22 nd 2005 F. COURAU M. OLSSON
Introduction 2 Policy and Regulation n Network Sharing n IP Multimedia System IMS regulation – June’ 05
Network Sharing 3 NETWORK SHARING: Regulation to impose sharing of part of the network elements between two or more operators on a regional basis IMS regulation – June’ 05
Network sharing in Release 99, 4 and 5 4 CN PLMN 1 CN PLMN 3 One Radio per PLMN IMS regulation – June’ 05 CN PLMN 2
Network sharing in Release 6 5 CN PLMN 1 Different PLMNS on a single radio IMS regulation – June’ 05 CN PLMN 2 CN PLMN 3
IP Multimedia System
IP support in Mobile Network 7 A bit of history n Support of IP services was first introduced in GSM networks in Release 97 of the specifications as complement to the Circuit Switched Services n The packet services was introduced in such a way that it did not destabilize the provision of Circuit Switched services and it also minimized the impact on the Radio part. n The specifications defines a mobile specific architecture taking the roaming and the mobility aspects into account and offering a differentiated Quality of Service n When defining the third generation systems (Release 99) the support of packet services was fully integrated in the architecture n Release 99 for both GSM and UMTS introduced the notion of Quality of Service (Background, Real time, Interactive) IMS regulation – June’ 05
GPRS Architecture Overview 8 ISDN MSC/VLR BSS with PCU HLR SGSN GGSN Frame Relay GPRS Mobile Internet X. 25 GPRS Backbone DNS DHCP IMS regulation – June’ 05
General Architecture Overview 9 Other Accesses (e. g. Wi. Fi CDMA 2000) IP Multimedia Subystem IP Multimedia Network UTRAN Packet Switched Domain BSS/GERAN IMS regulation – June’ 05 Circuit Switched Domain IP Network PSTN / CS PLMN
Main IMS Features A Multi-phase Standardisation 10 IMS Phase 1 - 3 GPP Rel 5 ü ü ü ü SIP Session Control for IMS Signalling Security & IMS Authentication : ü SIP signalling integrity (IPSec : UE / P-CSCF) ü IMS User/Service authentication (IMS-AKA) Qo. S : ü SBLP (Go : P-CSCF-PDF / GGSN-PEF) ü SIP Compression (Sigcomp, UE/P-CSCF) ü Header compression in RAN (UE / RNC, re-use of Ro. HC) Charging (mainly Offline) and OAM&P Multimedia codecs OSA support CAMEL (Phase 4) for IM-SSF IPv 6 use for SIP signalling and IMS user traffic ü IPv 4 optional (guidelines & IPv 6 evolution) IMS Phase 2 - 3 GPP Rel 6 ü ü ü ü Inter-working with non-IMS IP networks (e. g. Internet) Inter-working with CS networks (e. g. PSTN, CS PLMN) IMS Services combining CS (rt) & PS (nrt) : CSI Phase 1 Access agnostic IMS specifications UTRAN Qo. S optimisation for PS conversational services WLAN/3 GPP inter-working for using PS/IMS services Presence/Instant Messaging (SIMPLE) OMA Group management & Conferencing (SIP) Immediate and Session based messaging Service enablers for IMS : Po. C OMA Dynamic Qo. S policy (including Gq (P-CSCF/PDF)) Lawful interception SIP forking Full charging framework (incl. Online and Flow based) IPv 4 option & IPv 6 evolution guidelines still applicable IMS ‘Phase 3’ - 3 GPP Rel 7 (Draft contents, depends on Rel 6 and company proposals) Emergency services IMS local services Enhanced Qo. S (extension for IP Inter-working) MRFP / MRFC (Mp) & ALG/Tr-GW (Ix) interfaces GERAN optimisation for PS conversational services IMS regulation – June’ 05 ü IMS enhancements for Fixed Broadband access ü Interim Security (IP based authentication) ü Merging of Go and Gx (TPF/FBC) interfaces
I M S IP Multimedia Subsystem 11 IMS n Primarily designed (3 gpp R 5) to work on top of GPRS using SIP signalling n But extended (3 gpp R 6) to work on top on non-GPRS based access and SIP TEs (Harmonised with the 3 GPP 2 (CDMA 2000) IP Multimedia Domain (MMD)) n On going work with ETSI TISPAN to adapt IMS for requirements of fixed networks Services on top of IMS (e. g. MMS, Po. C, IM/PM, DRM, DM are also developed by other organizations like OMA. Other Accesses (e. g. Wi. Fi CDMA 2000) IP Multimedia Subystem UTRAN BSS/GERAN IMS regulation – June’ 05 Packet Switched Domain Circuit Switched Domain IP Multimedia Network IP Network PSTN / CS PLMN
3 GPP IMS Architectural Overview 12 HSS Application AS IMS Data Handling IM SSF SIP AS SLF (Ext. SIP AS, OSA AS, CAMEL SE) OSA SCS HLR/Au. C (‘CS/PS’) CSCF BGCF S-CSCF I-CSCF MGCF P-CSCF MRF PDF IMS Terminal TE IMS regulation – June’ 05 AN IP CAN PE F/T PF ABG ‘IMS IPGW MRFC ALG MRFP Tr. GW IPv 4/IPv 6 BB SGW CS Networks (PSTN, CS PLMN) IMS-MGW IPv 4 PDN (IPv 4 Network) BG IPv 6 PDN (IPv 6 Network)
Main IMS principles 2 phase registration, 13 GPRS UE 1. Bearer Level Registration: e. g. GPRS Attach (2. Establishing signaling link e. g. PDP Context Activation) 3. CSCF Discovery 4. Application (IMS) Level Registration specific (Qo. S, charging, security, ) at Access and at IMS case IMS regulation – June’ 05 IMS
IMS in PLMNs & Roaming 14 P-CSCF / PDF are located in the same network as GGSN The S-CSCF is always located in the Home Network Two possible Cases Proxy CSCF in Visited Network IM CN SUBSYSTEM Service Network P-CSCF GGSN This case is possible too S-CSCF / AS Gi S-CSCF / AS Home Network IM Subsystem Virtual presence of UE in visited network IM subsystem (UE’s IP-address is here) PDP Context UE SGSN BG Inter-Network IP Backbone BG P-CSCF Visited Network IM Subsystem Access network connecting the user UE SGSN Proxy CSCF in Home Network Visited Network GGSN Gi Internet PDP Context Intranets This is in fact the GPRS roaming case IMS regulation – June’ 05
IMS Communication Focus Example with two Roaming IMS Mobile Users 15 Serving Network A Serving Network B Access Network A P-CSCFC PDF Gm SIP /SDP inviting uey@homeb. com Service Platform A (ASA ) SIP / SDP Service Platform B (ASB) SIP / SDP S-CSCFA SIP / SDP S-CSCFB Access Network B P-CSCFD PDF Gm Go SGSN Go Data- Path SIP /SDP GGSN SGSN IP Backbone Network UEA PDP Context UEB PDP Context Sessionlevel(SIP/SDP signalling) Bearer level(PDPcontext activation / modification /Release) Interactionbetweensession andbearer level(COPS) I-CSCF (between P-CSCF and S-CSCF) not shown for simplicity IMS regulation – June’ 05
IMS charging and Qo. S: interface between service and access network Subscription database Three types of charging Pre-paid IP Multimedia Subystem P-CSCF Packet Switched Domain (Access) IMS regulation – June’ 05 Access GW (GGSN) Policy and charging Relay Gq, Rx Go, Gx -On line charging -Off line charging -Flow based charging 16
Emergency & LI Overview ADMF = LI administration DF = Delivery Function (to LEA= Law Enforcement Agency) 17 For the target IMS only service, Emergency calls via IMS to be deployed (3 GPP R 7) n But absence of deployment of an IMS emergency infrastructure does not block deployment of IMS conversational service provided that UE or Network can detect emergency requests and direct them via CS domain A call back from Emergency Center is always directed to UE via CS domain LI infrastructure in PLMN (ADMF, DF) to be upgraded to take into account IMS and to inter-operate with CSCF. For 3 gpp, n IMS specific interception deals only with signaling plane interception. n User plane interception is to be carried out at Access level (GPRS) Note that user plane generally goes directly from UE to UE without being handled by any MGW (only IW with CS networks) in the network IMS regulation – June’ 05
LI for 3 GPP IP/IMS : Simplified Overview of Functional Architecture 18 X 1 IMC ADM F MM Call Server P-CSCF/ S-CSCF Radio Network HI 1 LEMF IMS Domain Gi Gn Iu/Gb Mobile LI target RAN X 1_2/3 p IP Backbone SGSN X 2 GGSN* HI 2 Gi Internet Signalling (incl. SIP) User Plane Management X 3 * Interception at GGSN is optional IMS regulation – June’ 05 3 GPP Interfaces Interception of signalling is called “IRI” = Intercept Related Information LIG DF 2/ DF 3 IPHI 3
Annex: A few abbreviations explained 19 Definitions n GPRS GGSN SGSN Gateway GPRS Support Node Serving GPRS Support Node n IMS API Application Program Interface AS Application Server BCSM Basic Call State Model BG Border Gateway BGCF Breakout Gateway Control Function CSCF Call Session Control Function MGCF Media Gateway Control Function MGF Media Gateway Function P-CSCF Proxy‑CSCF S-CSCF Serving‑CSCF IMS regulation – June’ 05
20 Thank You for Your Attention laurent. thiebaut@alcatel. fr & sajid. soormally@alcatel. fr Alcatel Mobile Solutions www. alcatel. com IMS regulation – June’ 05
21 IMS regulation – June’ 05
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