MWIF Gap Analysis MWIF BOD Led Core Network Standard Initiative Nov. 13th, 2001

Contents –Overview of 3GPP/3GPP2/MWIF NRAs –Brief comparison of 3GPP and 3GPP2 legacy components –Comparison of functionality of 3GPP/3GPP2/MWIF Core Network Reference Architectures –Summary of Gaps

Emergency Services Network 3G-HLR UTRAN BSS/ GERAN Fundamental requirement to support evolution from current GSM Circuit switched and GPRS Packet switched network in support Of an IP Multimedia Domain for IP based services support for UMTS. 3G-HLR G-MSC Server IP Multimedia Subsystem PS Domain 3G-SGSN 3G-GGSN R-SGW MGCF MGW PSTN/ Legacy/External T-SGW Legacy mobile signalling Network Multimedia IP Networks *this diagram has been modified from that in the specification for illustrative purposes. Any inaccuracies are unintentional Multimedia IP Networks Gr Gn Gc Gi Mm Mg Mc Gi Cx Mr MSC Server Gi Mb Gi Signaling only User Data and Signaling Ms BGCF Mi Mj Applications & Services SCP CAP CSCF Mw Application Service Control Transport CS Domain RAN 3G-HLR UMS HSS MRF Lg GMLC MTTE 3GPP Network Reference Architecture – R5*

Application Service Control Transport Media Gateway Control Roaming Signaling Gateway Service Application Network Capability Gateway Subscription QoS Manager Databases EIRDSISubPoli Trunk Signaling Gateway MAP 41 & GSM PSTN IP Network Session Control Manager Core QoS Manager Media Gateway Border Router Position Server Position Determining Entity AAA Legacy MS Domain Support Media Resource Function Mobile IP Home Agent Access Net. Access Gateway FA/ Attendant BSC + PCF BTS MM Other Access Networks MS Signaling-Control Bearer Radio CDMA selection for Packet Switch support was much more Internet friendly than the GSM GPRS choice. Thus, the CDMA All IP architecture (aka 3GPP2) defines more discrete IP based functional elements. 3GPP2 All IP Network Reference Architecture

Directory Services il Application Service Control Transport INTERNETIntranetPSTN MAP 41 & GSM Enterprise Home Mobility Manager Access Network TerminalUIM Access Gateway IP Address Manager Access Transport Gateway Mobile Attendant Transport Gateway Functional Entities Media Gateway IP Gateway Signaling Gateway Media Gateway Controller Multimedia Resource Function Communications Session Manager (CSM) Session Proxy Session Anchor AAA Functional Entities Authentication Server Home IP Address Manager Authorization Server Accounting Server Location Server Global Name Server Policy Repository Profile Server Application Functional Entities Core Network Application(s) 3rd Party Application(s) Multimedia Resource Controller Resource Manager Geographic Location Manager Service Discovery Server Bearer Signaling-Control Resource Directory MWIF NRA (MTR-004v2.0) MWIF’s objective was to define an Access Independent Core Network architecture based on IP.

Functional Element 3GPP (GSM evolved) 3GPP2 (CDMA evolved) Deltas Circuit Switch Call Control MSC, GMSC MSC, GMSC Functionally equivalent but different signaling protocols are used. Packet Switch Data SGSN/ GGSN PDSN, Mobile IP Home Agent 3GPP mobility is handled by the PS domain (and does not support heterogeneous access). 3GPP2 mobility is handled by the PDSN and the Mobile IP Home Agent User Subscription Data HLR Different formats for data Different signalling interfaces to access the data. Mobile Station UEMSGSM/UMTS supports separation of the subscriber (SIM) from the TE. UMTS - comprised of the Mobile Terminal (MT) and Terminal equipment.. CDMA - supports separation of the subscriber (SIM) from the TE. Functional Comparison of 3GPP & 3GPP2-Legacy

Functional Element 3GPP (R5) 3GPP2 (All IP) MWIFDeltas Access Gateway GGSNAccess Gateway (FA/Attendant) Access Gateway (Mobility Attendant, IP Address Manager, Access Transport GW) 3GPP GGSN is the Access Gateway from the perspective of the IM Subsystem. From the perspective of the RAN, the SGSN can be viewed as the Access Gateway. IP Address Manager and Access Transport GW are inherent functions of GGSN and 3GPP2 Access GW. Mobility Management SGSN/ GGSN Mobile IP Home Agent, Access Gateway Mobility manager, Access gateway 3GPP mobility is handled by the PS domain (and does not support heterogeneous access). 3GPP2 and MWIF mobility is based on IETF Mobile IP model. Media Gateway Control BGCF, MGCFL-SCM, MGCFSession Anchor, MGCL-SCM of 3GPP2 approximates the functionality of the 3GPP BGCF, but is not yet fully defined. Media Gateway MGWMedia Gateway None. All should be based upon MEGACO. Signaling gateway T-SGWTrunk Signaling gatewaySignaling gatewayNone, although, local signaling variants would require different “flavors” of Signaling Gateway. Legacy Roaming R-SGWRoaming signaling gateway Signaling Gateway3GPP/3GPP2 R-SGWs are functionally equivalent, however, protocols are different. MWIF does not have a specific functional element to handle the signaling for legacy roaming, this functionality is deemed to be part of the Signaling Gateway. Functional Comparison of 3GPP-3GPP2-MWIF

Functional Element 3GPP3GPP2MWIFDeltas Multimedia Resource Functions (Conf/Annc Servers) MRFMedia resource Function MRC, Media Resource Function MWIF specifies a separate controller from the Media Resource Function. 3GPP specifies the MRC as part of the MRF. AAA HSS, S-CSCFAAA 3GPP has defined the Cx interface to be DIAMETER, thus an AAA infrastructure is assumed to be part of the architecture, however, the functionality is distributed amongst the entities, thus it’s not entirely clear that AAA infrastructure is deemed to be logically separate from functions such as Session Management or Directory Services. QoS PCF (part of CSCF), GGSN Core & subscription QoS managers, Access Gateway, Border Router Resource manager, Access Gateway All similar in that the QoS Policy Enforcement is done by Access Gateway and Policy data is part of the Database. Interfaces and control flow slightly different. Location of PDP different, but logically equivalent to the IETF model. QoS Policy data is in the databases, auth models are different. Geographic Position GMLC, SMLCPosition Server, Position Determining Equipment Geographic Location Manager 3GPP GMLC/SMLC are access specific and used for support of emergency services. This information is not intended to be generic geographic location information. MWIF assumes Geo Location stored in the Location Server 3GPP2 defines a Position Server outside of the Databases. Databases HSSDatabasesDirectory servicesFunctionally equivalent. Each architecture has a different logical separation of data. Functional Comparison of 3GPP-3GPP2-MWIF

Functional Element 3GPP3GPP2MWIFDeltas Session Management CSCF (S-CSCF, P-CSCF, I- CSCF) SCM (S-SCM,I-SCM, E-SCM,P-SCM, L- SCM) CSM, Session Proxy,S-CSCF, S-SCM and CSM functionally equivalent P-CSCF, P-SCM and Session Proxy equivalent I-CSCF and I-SCM appear to be functionally equivalent (THIG?). This role in MWIF would be partly subsumed by the Session Proxy (Interrogating role). The Topology hiding part could be done with a Firewall (or a more specialized middlebox). Services S-CSCF, Applications & Services S-SCM, NCGW CSM For all the architectures, there will be some services inherent to the Session Managers (S- CSCF, S-SCM, and CSM). Due to the different interfaces, MWIF supports services via the interfaces from the CSM to the AAA entities, Policy, Directory Services, thus the infrastructure is inherently “Service” Oriented. 3GPP2 NCGW role is between Application and Session Mgmt and is more a central point of control. It plays a role in Application Authorization. It is based on the 3GPP OSA gateway. Applications Applications & Services Service applicationCore Network applications, 3 rd party applications Theoretically, there should be none, however, in the end requirements may result in some differences. There may also be differences in the level of programmability for the applications. Service Discovery --Discovery Server MWIF defines separate element for determining service availability. 3GPP restricts the user to the selection of the S- CSCF. (may support this function in R6). Functional Comparison of 3GPP-3GPP2-MWIF

Summary of Gaps Areas with largest gaps: –Legacy support – support for this in a generic manner isn’t possible due to differences in signaling mechanisms, databases, etc. Requires specific protocol inter-working elements. –Mobility support – in order to support heterogeneous access across the different networks (and with additional flavors of access networks), an access independent Mobility mechanism (e.g. IETF Mobile IP based) would be needed to be supported by 3GPP.

Summary of the Gaps Areas with gaps that could prove significant: –The degree to which 3GPP and 3GPP2 deviate or require additions to the IETF SIP protocol could further increase the delta between the 2 networks. –Common mechanism for Geographic Location across the networks (access independent) for support of such things as Emergency calls. –Subtle differences in functional elements like MRF increases the likelihood of services and applications NOT being consistent across the platforms. –Lack of a more formalized AAA infrastructure in the IM Subsystem for 3GPP increases the likelihood that this functionality is not clearly separated from Session Control, Databases (and even areas like Service Authorization).

Summary of the Gaps Areas with workable gaps: –QoS mechanisms and control flow in an access independent manner where possible (with alignment to IETF mechanisms).

Conclusion and next steps –Create a set of operation and business requirements from MWIF’s gap analysis for harmonization –Utilize requirements to formally and informally influence standardization – Initial activities will include: Provide operation and business requirements for OHG’s harmonization meeting in 1Q02 MWIF operators will work behind the scenes to proactively garner support for the requirements –Develop realistic incremental steps to meet harmonization requirements