Policy and Regulatory Requirements for Future Mobile Networks June 22nd 2005 F. COURAU M. OLSSON

Introduction Policy and Regulation Network Sharing IP Multimedia System IMS

Network Sharing NETWORK SHARING: Regulation to impose sharing of part of the network elements between two or more operators on a regional basis

Network sharing in Release 99, 4 and 5 CN PLMN2 CN PLMN1 CN PLMN3 One Radio per PLMN

Network sharing in Release 6 CN PLMN2 CN PLMN1 CN PLMN3 Different PLMNS on a single radio

IP Multimedia System

IP support in Mobile Network A bit of history Support of IP services was first introduced in GSM networks in Release 97 of the specifications as complement to the Circuit Switched Services 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. The specifications defines a mobile specific architecture taking the roaming and the mobility aspects into account and offering a differentiated Quality of Service When defining the third generation systems (Release 99) the support of packet services was fully integrated in the architecture Release 99 for both GSM and UMTS introduced the notion of Quality of Service (Background, Real time, Interactive)

GPRS Architecture Overview ISDN MSC/VLR BSS with PCU HLR SGSN GGSN GPRS Mobile Frame Relay GPRS Backbone Internet X.25 DNS DHCP

General Architecture Overview Circuit Switched Domain Packet Switched IP Multimedia Subystem Other Accesses (e.g.WiFi CDMA2000) Network UTRAN BSS/GERAN IP Network PSTN / CS PLMN

Main IMS Features A Multi-phase Standardisation IMS Phase 1 - 3GPP Rel5 SIP Session Control for IMS Signalling Security & IMS Authentication : SIP signalling integrity (IPSec : UE / P-CSCF) IMS User/Service authentication (IMS-AKA) QoS : SBLP (Go : P-CSCF-PDF / GGSN-PEF) SIP Compression (Sigcomp, UE/P-CSCF) Header compression in RAN (UE / RNC, re-use of RoHC) Charging (mainly Offline) and OAM&P Multimedia codecs OSA support CAMEL (Phase 4) for IM-SSF IPv6 use for SIP signalling and IMS user traffic IPv4 optional (guidelines & IPv6 evolution) IMS Phase 2 - 3GPP Rel6 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 QoS optimisation for PS conversational services WLAN/3GPP 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 : PoC  OMA Dynamic QoS policy (including Gq (P-CSCF/PDF)) Lawful interception SIP forking Full charging framework (incl. Online and Flow based) IPv4 option & IPv6 evolution guidelines still applicable Emergency services IMS local services Enhanced QoS (extension for IP Inter-working) MRFP / MRFC (Mp) & ALG/Tr-GW (Ix) interfaces GERAN optimisation for PS conversational services IMS ‘Phase 3’ - 3GPP Rel7 (Draft contents, depends on Rel6 and company proposals) IMS enhancements for Fixed Broadband access Interim Security (IP based authentication) Merging of Go and Gx (TPF/FBC) interfaces

I M S IP Multimedia Subsystem Primarily designed (3gpp R5) to work on top of GPRS using SIP signalling But extended (3gpp R6) to work on top on non-GPRS based access and SIP TEs (Harmonised with the 3GPP2 (CDMA 2000) IP Multimedia Domain (MMD)) On going work with ETSI TISPAN to adapt IMS for requirements of fixed networks Services on top of IMS (e.g. MMS, PoC, IM/PM, DRM, DM are also developed by other organizations like OMA. Circuit Switched Domain Packet Switched IP Multimedia Subystem Other Accesses (e.g.WiFi CDMA2000) Network UTRAN BSS/GERAN IP Network PSTN / CS PLMN

3GPP IMS Architectural Overview Application (Ext. SIP AS, OSA AS, CAMEL SE) HSS OSA SCS IM SSF SIP AS AS IMS Data Handling SLF HLR/AuC (‘CS/PS’) CSCF BGCF S-CSCF I-CSCF MGCF P-CSCF MRF SGW ‘IMS IPGW MRFC PDF ALG CS Networks (PSTN, CS PLMN) MRFP TrGW IMS-MGW IPv4 PDN (IPv4 Network) IP CAN PEF/TPF IPv4/IPv6 BB IMS Terminal ABG TE AN BG IPv6 PDN (IPv6 Network)

Main IMS principles 2 phase registration, UE GPRS IMS 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 (QoS, charging, security,) at Access and at IMS case

IMS in PLMNs & Roaming Two possible Cases Proxy CSCF P-CSCF / PDF are located in the same network as GGSN Two possible Cases The S-CSCF is always located in the Home Network Home Network Visited Network IM Subsystem Inter - Network IP Backbone Internet Intranets UE GGSN BG SGSN PDP Context Gi Virtual presence of UE in visited network IM subsystem ( UE’s IP address is here) Proxy CSCF in Visited Network P-CSCF S-CSCF / AS This case is possible too IM CN SUBSYSTEM Service Network P-CSCF S-CSCF / AS Gi GGSN PDP Context UE SGSN Access network connecting the user Proxy CSCF in Home Network This is in fact the GPRS roaming case

IMS Communication Focus Example with two Roaming IMS Mobile Users Serving Network A Serving Network B Access Network A Service Platform A Service Platform B Access Network B (AS ) (AS ) A B P- CSCF SIP / SDP SIP / SDP SIP / SDP P- CSCF C D S -CSCF S -CSCF PDF A B PDF Gm Gm SIP / SDP Go Go SIP / SDP inviting uey@homeb.com SGSN GGSN Data- Path GGSN SGSN IP Backbone Network UEA UEB PDP Context PDP Context Session level (SIP/SDP signalling ) Bearer level (PDP context activation / modification / Release) Interaction between session and bearer level (COPS) I-CSCF (between P-CSCF and S-CSCF) not shown for simplicity

IMS charging and QoS: interface between service and access network Subscription database Three types of charging On line charging Off line charging Flow based charging Pre-paid IP Multimedia Subystem P-CSCF Policy and charging Relay Gq,Rx Access GW (GGSN) Packet Switched Domain (Access) Go,Gx

Emergency & LI Overview ADMF = LI administration DF = Delivery Function (to LEA= Law Enforcement Agency) For the target IMS only service, Emergency calls via IMS to be deployed (3GPP R7) 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 3gpp, IMS specific interception deals only with signaling plane interception. 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

LI for 3GPP IP/IMS : Simplified Overview of Functional Architecture X1 HI1 IMC MM Call Server P-CSCF/ S-CSCF ADMF Radio Network LEMF IMS Domain Gi X1_2/3p 3GPP Interfaces Iu/Gb Gn X2 IP HI2 Backbone Gi RAN SGSN GGSN* Mobile LI target Internet LIG IP- HI3 Signalling (incl.SIP) X3 DF2/ DF3 User Plane Management * Interception at GGSN is optional Interception of signalling is called “IRI” = Intercept Related Information

Annex: A few abbreviations explained Definitions GPRS GGSN Gateway GPRS Support Node SGSN Serving GPRS Support Node 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

Thank You for Your Attention Alcatel Mobile Solutions laurent.thiebaut@alcatel.fr & sajid.soormally@alcatel.fr Alcatel Mobile Solutions www.alcatel.com