1. Nortel Confidential Information 1 Core network integration issues for inter- RAT, inter-SDO mobility (HRPD – WiMax Focus) Nortel

2. Nortel Confidential Information 2 Harmonizing core network functionality Most SDOs have some form of an ‘All IP’ core network that incorporates IETF defined functional elements and protocols. However, each SDO defines their own ‘All IP’ architecture and procedures for how these IETF tools are utilized. Specifically, each SDO defines its own policy framework, AAA framework and mobility management solutions. Therefore, inter-working between radio access technologies that are defined by different SDOs requires a much broader scope than just mobility management alone. This contribution highlights the other topics that require consideration (policy, authentication) and it suggests four potential core network solutions.

3. Nortel Confidential Information 3 Policy Frameworks Current releases of other SDOs with dynamic policy control (3GPP2 All-IP, TISPAN R1.0) use off-path signaling All new releases incl. WiMAX specify the ref. point to ASN/visited network to be: bearerless (provide IP flow information per individual AF session) out of band (Diameter-based) off-path (WiMAX also allows parallel option) Bearerless, off-path model is agreed at ITU-T level in Rec. Y.2111 for Policy Control of Next Generation Networks WiMAX R1.5 PCC (draft) 3GPP2 evolved network architecture (draft) TISPAN RACS R2 Architecture (draft) AF Rx (Tx) Gx/(Ty) R3 R6 SFM BS SFM BS R4 ASN PCRF C-PCEF Anchor SFA A-PCEF Anchor SFA A-PCEF MS HA CSN Policy Distribution Function Policy Distribution Function Serving SFA PCC-R3 PCC-based AAA OCS/ OFCS OCS/ OFCS Visited Network eBS serving AGW serving AGW LMA/HA AF AT Tx anchor AGW anchor AGW implementation option Home Network U18 V-PCRF VAAA H-PCRF HAAA U23 U20 U15 U16 NGN Access Network Provider NGN Connectivity Provider Access Node Access Node IP Edge IP Edge A-RACF v-NASS SPDF h-NASS Core Border Nd Core Border Nd AF SPDF UE Ri’ Di Re e4 Ds Ia Gq’ Sources: WiMAX PCC NWG Rel 1.5 (Unapproved draft, March 2007) X50-2070514-030r8 Proposed text for X.P00xx-000 UMB Network Specification Draft ETSI TS 182 019 V0.6.1; TISPAN; Resource and Admission Control Sub-system (RACS) Rel 2.0; (2007-05)

4. Nortel Confidential Information 4 AAA Frameworks EAP Method (EAP-TLS, EAP-AKA, EAP-MD5, etc..) EAP MSBTSGWProxyAAA AAA ProtocolEAP Transport UDP / IPData Link Encap. User Identity Alignment? Authenticator Authenticator Location? Which EAP methods? RADIUS, DIAMETER or Both? Is it EAP in both RATs? Single or Double EAP? Common AAA server?

5. Nortel Confidential Information 5 Core network integration for inter-RAT mobility models: Pair-wise coupling Model: WiMAX integrated under HRPD architecture HRPD integrated under WiMAX architecture IETF-based Common Core Core elements meet both WiMax and 3GPP2 requirements 3GPP EPC Model: WiMAX and HRPD integrated under 3GPP EPC architecture EPC architecture has specified a number of non-3GPP interfaces and protocols that can be leveraged for inter-working with EUTRAN and between other RATs. CAN WiMAX and HRPD both integrated under CAN architecture. CAN architecture has specified non-3GPP2 interfaces, but has yet to define how policy, authentication and mobility will behave.

6. Nortel Confidential Information 6 WiMAX BTSRNCPDSN IMS (CSCF) AAA HRPD HA BTS PCRF ASN GW ASN A10, A11 R6 R3 AAA HA CSN PF Staring Point (non-roaming) Ty

7. Nortel Confidential Information 7 WiMAX BTSRNCPDSN IMS (CSCF) AAA HRPD HA BTS PCRF PF ASN GW ASN A10, A11 R6 R3 AAA HA CSN PF WiMax integrated into HRPD architecture (non-roaming) Ty R3/PCC Tx/Rx? Tx or Rx semantics? Authentication, credential and identity alignment Migration to PMIPv6? WiMax aligns to the HRPD core network.

8. Nortel Confidential Information 8 WiMAX BTSRNCPDSN HRPD BTS ASN GW ASN A10, A11 R6 R3 AAA HA CSN PF WiMax integrated into HRPD architecture (non-roaming) Ty modification? Service Authentication? MIP evolution? Ty modification? Service Authentication? MIP evolution? IP Services Ty HRPD aligns to the WiMax core network.

9. Nortel Confidential Information 9 WiMAX BTSRNCPDSN HRPD BTS ASN GW ASN A10, A11 R6 WiMax and HRPD integrated into common IETF Core IETF core relies on vendors to meet both WiMAX forum and 3GPP2 requirements IMS (CSCF) AAA HA PCRF PF Common IETF Core Ty R3 HA support both HRPD MIPv4 (IS835) and WiMax PMIPv4 (NWGv1.0) The PCRF / PF supports both Ty and R3/PCC semantics and a common Rx/Tx solution. AAA support different authentication schemes and EAP methods. IP services

10. Nortel Confidential Information 10 WiMAX AT/eAT eANePDSN AN eHRPD BTS ASN GW ASN R6 S2a PMIPv6 Legacy HRPD HA AN AAA PCRF S7a HRPD and WiMax architecture integrated under EPC (non-roaming) IMS (CSCF) HSS/ AAA P-GW PCRF PF AAA S2a PMIPv6 PDSN S7a AAA Tx Ty AAA WiMax support PCC R.7. WiMax R1.5 is considering PMIPv6. WiMax support PCC R.7. WiMax R1.5 is considering PMIPv6. Re-use ePDSN framework as is proposed for LTE- HRPD inter-working. IP services

11. Nortel Confidential Information 11 WiMAX HRPD AN SRNC aGW HRPD AN 1xEV-DO V-LMA PDSN BTS vPCRF ASN GW ASN R6 eBS UMB Legacy 1xEV-DO H-LMA CMIP PMIP CMIP H-AAA hPCRF V-AAA IP services U19a U24a U22a WiMax and HRPD integrated into 3GPP2 CAN architecture

12. Nortel Confidential Information 12 Summary – Finding a common reference architecture Service providers will deploy and support a mixture of legacy and emerging technologies. Sometimes more that one emerging technology. Inter-technology HO requirements will vary – reference architecture should accommodate both different performance requirements A common reference architecture must be the starting point for the discussion of all technology pairings. The reference architecture must cover: Mobility Authentication / Security Policy Charging Fixed / Mobile convergence Some technology pairings have already settled on a reference architecture HRPD-LTE (based in EPC) (agreed in 3GPP, decision in 3GPP2 pending) HRPD-UMB (based in CAN) WiMax-HRPD (TBD)