1. ABSTRACT: This contribution proposes the HRPD-WiMAX handoff solution. TITLE: HRPD-WiMAX Handoff TSG-A WG4 RECOMMENDATION: Review and Adopt Samsung Electronics grant a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. Samsung Electronics are also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution. This document has been prepared by Samsung Electronics to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on Samsung Electronics. Samsung Electronics specifically reserves the right to amend or modify the material contained herein and to any intellectual property of Samsung Electronics other than provided in the copyright statement above. DATE: November 5, 2007 Notice SOURCE: Samsung : Bill Semper and BeomSik Bae b.semper@samsung.com, bsbae@samsung.comb.semper@samsung.combsbae@samsung.com

2. 1 Principles Single radio operation –Dual radio operation should be supported, but is not mentioned in this material. Support bi-directional handoff Support for active handoff for real-time service (such as VoIP) –To maximize handoff performance, session setup (e.g. HRPD session, PPP setup, and CMIP/PMIP binding update) should occur before handoff commences HRPD-WiMAX handoff solution may impact existing infrastructure as little as possible –Minimum change of legacy HRPD networks. –IOS signaling interfaces should be used as much as possible Minimal impact on terminal complexity

3. Overview AT performs pre-registration/pre-setup with target RAN node (HRPD AN or WiMAX BS). IP-level tunneling method is used for pre-registration/pre- setup. –WiMAX->HRPD: AT communicates with HRPD AN over IP-level tunnel through WiMAX network without service interruption. HRPD session negotiation Device authentication Set up of PPP session User authentication TFT configuration MIP registration –HRPD->WiMAX: AT communicates with WiMAX BS over IP- level tunnel through HRPD network without service interruption. IP-level tunneling can be considered as just another IP applications in HRPD network.

4. Handoff Architecture Basic architecture PDSN AN HA/LMA BS PCF (SC/MM) ASN-GW AT HRPD WiMAX A8/A9/A14/A20 A10/A11 AAA IP connectivity IP connectivity Note: HRPD architecture is based on A.S0009

5. IP-level Tunneling Example (HRPD to WiMAX) PDSN AN HA/LMA BS PCF (SC/MM) ASN-GW AT HRPD WiMAX A8/A9/A14/A20 A10/A11 AAA IP connectivity L3 tunnel from AT to WiMAX BS

6. IP-level Tunneling Example (WiMAX to HRPD) PDSN AN HA/LMA BS PCF (SC/MM) ASN-GW AT HRPD WiMAX A8/A9/A14/A20 A10/A11 AAA IP connectivity L3 tunnel from AT to HRPD AN

7. Protocol Stack WiMAX to HRPD HRPD to WiMAX Note: IPsec can be used to provide secure IP-level tunnel.

8. Basic Call Flow: WiMAX to HRPD [1] AT AN ASN-GW PCF PDSN WiMAX HRPD WiMAX BS 5. HRPD session negotiation and device authentication 6. PPP establishment and user authentication 10. HO Indication IP Tunnel 12. Service over HRPD 3. Target AN discovery (e.g DNS lookup) 4. AT Authentication and IPSec establishment (if needed) 8. HO Decision IP Tunnel 9. Traffic Channel Assignment 11. HRPD Air access 1. Service over WiMAX 7. TFT configure, MIP Registration (FFS) 2. HRPD pilot detect Handoff trigger

9. Basic Call Flow : WiMAX to HRPD [2] Step 1: AT is in active state in WiMAX network Step 2: AT reaches the edge of WiMAX network and detects HRPD pilot Step 3: AT performs target HRPD AN discovery Step 4: If needed, AT and target HRPD AN can establish IPsec tunnel. Step 5/6/7: AT and target HRPD network configure HRPD session, establish PPP session, perform device/user authentication, and configure TFTs like legacy HRPD setup Step 8/9: If handoff is decided, the target AN sends Traffic Channel Assignment message to AT through IP tunnel –We can consider other implementation architecture with lite AN. With that architecture, this may be different. Step 10/11: AT tunes from WiMAX carrier to HRPD carrier and accesses to HRPD. Step 12: After completing the air interface establishment, the service for AT is continued.

10. AT AN ASN-GW PCF PDSN WiMAX HRPD WiMAX BS 5. Authentication and 802.16 Registration procedure (IEEE802.16 & WiMAX standard) 10. HO Indication IP Tunnel 12. Service over WiMAX 3. Target BS discovery (e.g DNS lookup) 4. IPSec establishment (if needed) 9. HO Decision 11. WiMAX Air access 1. Service over HRPD 2. WiMAX detected Handoff trigger Basic Call Flow: HRPD to WiMAX [1]

11. Basic Call Flow: HRPD to WiMAX [2] Step 1: AT is in active state in HRPD network Step 2: AT reaches the edge of HRPD network and WiMAX BS is advertised. Handoff preparation is triggered by AN or AT. Step 3: AT performs target WiMAX BS discovery –DNS lookup (FQDN can be generated based on neighbor list information) Step 4: If needed, AT and target WiMAX BS can establish IPsec tunnel. Step 5-8: AT and target WiMAX network perform authentication, registration, and connection establishment. (IEEE802.16 & WiMAX standard) Step 9: Handoff from HRPD to WiMAX is decided by AN or AT. Step 10: HRPD AN sends HO indication to AT (FFS). Step 11: AT access WiMAX air interface using negotiated parameters. (IEEE802.16 & WiMAX standard) Step 12: After completing air interface establishment, service for the AT continues.

12. Conclusion Samsung proposes IP-level tunneling method to support HRPD-WiMAX handoff –Has minimal impact on legacy systems. –Seamless handoff for real time service (e.g. VoIP) can be achieved. –Bi-directional Less standard impact –If CMIP is used, PDS standard impact is small. –Reuse most of existing standards. PMIP should be supported: –[FFS] Samsung recommends that this approach be adopted for HRPD-WiMAX interworking