Event Services and Command Services for Media Independent Handover

1. Event Services and Command Services for Media Independent Handover Presentation prepared by: Srini Sreemanthula Presented by: Greg Daley, with some additions MIPSHOP IETF 64 MIPSHOP – November, 2005

2. IEEE 802.21 Introduction • IEEE 802.21 WG defines media independent handover (MIH) services that enable handoffs from one link technology to another involving subnet changes • MIH services aid in handoff based on existing mobility management protocols • MIH services are classified as 3 types • MIH Information Services • MIH Command Services • MIH Event Services MIPSHOP – November, 2005

3. What MIH provides • MIH service carry L2 information that is processed locally or carried to some other network node, remotely • MIH Services enable two facets of inter-technology handover • Inter-technology Network selection • Handover control MIPSHOP – November, 2005

4. ES/CS Introduction • Event Services (ES) provide: • indications from one layer or functionality to another about changes in the connectivity state. • Remote ES convey information from one network node to another • Command Services (CS) provide: • mechanisms for controlling handovers or functions aiding handovers. • mechanisms to establish, redirect, or remove state in either the network or mobile node, so that handovers occur smoothly. • Remote CS convey information from one network node to another MIPSHOP – November, 2005

5. Motivations • 802.21 functional definitions are to enable two scenarios • Terminal centric/controlled • Network centric/controlled MIPSHOP – November, 2005

6. Terminal Controlled Handover • Terminal makes all the decisions of network selection and initiates HO control • Can utilizes native L2 signaling or L2/L3 MIH ES/CS and L3 IS services • Used in operator, enterprise or individual user scenarios MIPSHOP – November, 2005

7. Network Controlled Handover • Network makes decisions of network selection in coordination with the terminal and initiates HO control • Assumption is that • network selection is in core network (beyond L2) • HO control resides where MME (common to both accesses) resides (beyond L2) • This requires that L3 MIH IS, ES and CS services are available • Important for operator models with multiple access technologies MIPSHOP – November, 2005

8. Motivation Summary • Higher layer MIH ES/CS services provide architectural flexibility for 802.21 deployment • does not need 802.21 in certain link technologies • ES/CS are utilized for both network selection and handover control • Applicable to network entity common to both media types • Not scalable to provision these functions within subnet • Easier and faster 802.21 adoption in other SDO e.g. 3GPP • Can coexist or share functions with MIH ES/CS at L2 MIPSHOP – November, 2005

9. ES/CS Service Model • Event Service model • Command Service Model Other triggers Other Sources Other triggers MIHF (ES) MIH (ES) Other Sources Remote ES Link Indications Link Indications Network Node Link Layer Link Layer Network Node Other layers/ functions Commands MIHF (CS) MIH (CS) Remote CS Link Commands Commands Network Node Link Layer MME Network Node MIPSHOP – November, 2005

10. Usage ModelsDirect and Proxy models • Direct model • Proxy model Remote ES/CS MIHFUE MIHFMME MIHFUE Remote ES/CS MIHFproxu Remote ES/CS MIHF MIPSHOP – November, 2005

11. MME MIHFNW(IS) MIHFUE 802.11-AN 802.11-AN MAC Layers 802.16-AN NW Initiated NW Selection UE Network Operator UE Discovery and Registration MIH-Register-Event.Req() MIH-Register-Event.Resp() DL-Burst* Link-Detect Link-Event.Detect(link_info) MIH-Info.Req MIH-Info.Resp Unfavorable Network Beacon Beacon Link-Detect Link-Event.Detect(link_info) MIH-Info.Req MIH-Info.Resp Favorable Network => Selection MIPSHOP – November, 2005

12. 802.11-AN MIHFUE Mobile IP HA New-FA 802.11 MAC MME NW Controlled HO Operator Network UE 802.11 Network Network Selection Legend Mobile-IP Signaling MIH-Remote-Link-Switch.Req(802.11 nwk) MIH signaling over new link L3-switch.Ind Proxy Rtr Solicitation Proxy Rtr Advertisement Link-Associate L2-Procedures (Security, Re-association, QoS Neg.) Link-Event-Up(802.11 nwk) MIH-Link-Event-Up FBU Mobile IP update procedure over new link Release MIH-Remote-Link-Switch.Resp MIPSHOP – November, 2005

13. Remote ES/CS Feasibility • Discussion relevant due to: • Adoba, B., "Architectural Implications of Link Indications draft-iab-link-indications-03.txt", June 2005. • Explicit signaling required • Intertechnology handover may not result in IP subnet change • Mitigation of security issues • Trust issues • Mapping of identifiers • Done at the UE MIPSHOP – November, 2005

14. Explicit Signalling • Command and event signalling • Implicit signalling possible • when path changes or link-aware routing metrics from access network • Explicit signaling required • Intertechnology handover may not result in IP subnet change • May inform devices of mobility management issues which aren’t apparent in the current access net • Needs safeguards to ensure damping/robustness MIPSHOP – November, 2005

15. Mobile Node Network Appl/ MIHF Link- MME Trans/ ES/CS Layers Netw Mapping of Local Identifiers Discovery Registration Authentication Security Association Media independent host ID Identifier Mappings • May be possible to make identifier mappings MIPSHOP – November, 2005

16. ES/CS Higher Layer Requirements • Work is similar to IS higher layer MIIS for • Identifying usage scenarios • Provisioning models e.g. proxy and direct • Finalizing ES/CS MIH functionality • Message sequences, message types, data elements associated with each message • Other higher layer requirement categories • Transport Layer • Discovery • Registration and Deregistration • Capability negotiation • Security • Reliability and failure recovery MIPSHOP – November, 2005