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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 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 •MIH •MIH MIPSHOP – November, 2005 Information Services Command Services Event Services 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 intertechnology handover • • Inter-technology Network selection Handover control MIPSHOP – November, 2005 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 Motivations • 802.21 functional definitions are to enable two scenarios •Terminal centric/controlled •Network centric/controlled MIPSHOP – November, 2005 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 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 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 ES/CS Service Model • Event Service model Other Sources Other triggers MIHF (ES) Remote ES Link Indications Network Node MIH (ES) Other triggers Link Indications Link Layer Network Node Link Layer • Command Service Model Other Commands layers/ functions MIHF (CS) Link Commands Network Node MIPSHOP – November, 2005 Link Layer Remote CS MIH (CS) Commands MME Network Node Other Sources Usage Models Direct and Proxy models • Direct model Remote ES/CS MIHFUE MIHFMME • Proxy model MIHFUE MIPSHOP – November, 2005 Remote ES/CS MIHFproxu Remote ES/CS MIHF NW Initiated NW Selection UE MIHFUE Network Operator MME MAC Layers MIHFNW (IS) 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 Link-Detect Beacon Link-Event.Detect(link_info) MIH-Info.Req MIH-Info.Resp Favorable Network => Selection MIPSHOP – November, 2005 802.16-AN 802.11-AN 802.11-AN NW Controlled HO Operator Network UE Mobile IP MIHFUE MME 802.11 MAC Network Selection MIH-Remote-Link-Switch.Req(802.11 nwk) 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 802.11 Network 802.11-AN New-FA HA Legend Mobile-IP Signaling MIH signaling over new link 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 MIPSHOP – November, 2005 at the UE 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 Identifier Mappings • May be possible to make identifier mappings Mobile Node Appl/ Trans/ Netw MIHF ES/CS Network LinkLayers Mapping of Local Identifiers Discovery Registration Authentication Security Association Media independent host ID MIPSHOP – November, 2005 MME 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