Network-based Mobility Extensions (NetExt) BOF proposal: ------------------------------------------------------- Background and Motivation: ------------------------- Proxy MIP6, which is the IETF Network-based Mobility Protocol specified in RFC 5213, has been incorporated into the evolved architecture of Long-Term Evolution (LTE) and Wimax networks. The respective standards organizations are in the process of specifying the Proxy MIP6 protocol for their current requirements and outlining the enhancements for subsequent releases of these networks. In light of the above, the following observations can be made: o as the trials and deployments of 4G networks are expected to begin in 2009, their evolution to support features such multihoming, inter-access technology handovers and localized routing continues o while the base PMIPv6 protocol is completed, improvements are necessary in some areas, most notably multihoming and inter-access technology handovers o certain deployment considerations, including localized routing and bulk refresh of lifetime are already emerging In summary, improvements, deficiencies and deployment considerations are identified to extend the network-based mobility (i.e., PMIPv6) to better meet the evolution of 4G mobile networks. Prior activity: -------------- The NetExt Bar BoF was held during the Dublin IETF meeting on Thursday, July 31 from 1300 - 1500. The primary purpose of the BOF was to investigate problems of relevance to the Network-based mobility protocol (i.e., PMIPv6) and its adoption in the industry. Three main categories of problems - Improvements, Deployment Considerations and Deficiencies were discussed. There were a total of 12 presentations, and a summary presentation/discussion was held in the final half hour. There was consensus that the current charter and roadmap of the NETLMM Working Group makes it imperative to pursue the above-mentioned categories of problems in a separate, complementary WG. There was overwhelming support among the approximately 40 people who attended the Bar BoF in working on the proposed items. There were no objections to creating a potential WG in the Internet Area. Proposed Work: ------------- The proposed NetExt Working Group will focus on the following topics relevant for network-based mobility: Improvements: o Multihoming: a specification including the target scenarios, preservation of IP sessions and load balancing (Proposed Standard) o Inter-access Technology handovers: a specification for IP session preservation when changing access technologies (PS) Deployment Considerations: o Localized Routing: a specification for constraining routing to the MAG(s) without involving the LMA within a single PMIPv6 domain (PS) o Bulk Refresh: specification of improving the signaling load for binding lifetime refresh (PS) Deficiencies: o MN involvement: documentation of scenarios where MN involvement may be seen as beneficial (Informational) The BoF proposes to discuss the above items and gauge interest in forming a working Group. There is already work in progress addressing the identified problems, which is expected to be the starting point for the deliverables. The proposed activity will be complementary to the existing IETF Working Groups, notably the NETLMM and MEXT WGs. Approximate Timeline for Deliverables: ------------------------------------- December 2008 WG approved by IESG 2H09 Submit Inter-access Tech Handover, Localized Routing and Multihoming I-Ds to IESG 4Q09 Submit the I-D on MN Involvement to IESG 1Q10 Submit Bulk Refresh I-D to IESG 2H10 Recharter or close WG Relevant Activity: ----------------- In WiMAX forum the Network Working Group (NWG) is specifying PMIP6 as part of Release 1.5 and work on Release 1.5 is expected to be completed by the end of the year (2008). NWG has also specified interworking with the 3GPP Rel 8 Evolved Packet Core using PMIP6 (S2a reference point). In 3GPP, PMIP6 is part of the IP mobility solution and enhancements to the protocol to support inter-technology handover as well as other optimizations are being considered for Rel 8 and Rel 9. Multihoming with simultaneous 3GPP access and non-3GPP access is being considered for better user experience as well as traffic offloading. 3GPP2 has also specified PMIP6 as part of IS-835 Rev E. Specification is nearing completion on handovers between the HSGWs (HRPD Serving Gateways), which is based on PMIP6 Fast Handovers being specified in IETF (MIPSHOP WG). Inter-technology handover between WiMAX and 3GPP networks as well as WiMAX and 3GPP2 networks is now being specified in WMF and 3GPP/2. PMIP6 is one of the solutions which enables handover and session continuity. There is expectation that additional work on enabling inter-tech HO using PMIP6 is needed. It is better that the IETF specify a solution for inter-tech handover instead of every SDO doing something on their own. Localized Routing is of interest to all deployments involving real-time packet data services which can benefit from significant improvements in performance and backhauling costs. Reducing signaling overhead due to PMIP6 Binding Refresh is an important deployment consideration. Similarly, understanding the implications to the Mobile Node as PMIP6-based trials begin and extensions are proposed is important. There are a large number of companies that are active in 3GPP, WiMAX forum and 3GPP2 which have a keen interest in developing PMIP6. Companies which have expressed interest and plans to enhance PMIP6 for various purposes include Alcatel-Lucent, Cisco, Huawei, Nokia Siemens Networks, Samsung, Starent, ZTE, and many others. Many of the delegates in various SDOs from these companies are contributing to PMIP6 extensions for various features.