IEEE 802 21 Media Independent Handover MIH Raj Jain Professor of Computer Science and Engineering Washington University in Saint Louis Saint Louis MO 63130 Audio Video recordings of this lecture are available at http www cse wustl edu jain cse574 10 Washington University in St Louis CSE574S 14 1 2010 Raj Jain Overview Types of Handovers 802 21 Key Functions MIH Services MIHF Protocol Amendments for MIH Washington University in St Louis CSE574S 14 2 2010 Raj Jain Types of Handovers Old Old New Make before Break New Break before make Hard handover Break before Make Soft handover Make before Break Need to use two radios Horizontal Handover Same radio access technology RAT Vertical Handover Different technologies Terminal Controlled Terminal Initiated Network assisted Network Initiated Network controlled Washington University in St Louis CSE574S 14 3 2010 Raj Jain Intra Technology Handovers 802 11i defines pre authentication 802 11r is defining fast BSS transition 802 16e defines handover process optimization 802 1af is defining port access control revised 802 1X Most of these reduce handover time by preauthentication with next target using current service Washington University in St Louis CSE574S 14 4 2010 Raj Jain 802 21 History and Timeline 1H2004 WG created 1H2005 Initial draft 2H2005 Changes to 802 11u 802 16g MIPSHOP 1H2006 WG letter ballot 2007 Sponsor ballot 2008 Standard 2009 10 Deployments Washington University in St Louis CSE574S 14 5 2010 Raj Jain 802 21 Key Functions Reduce power consumption by avoiding unnecessary scanning and using information 802 16 module is turned on only if 802 16 is available Reduce power consumption by using backend core network Reduce handover time by passing security QoS information to next point of service Allow service providers to enforce their policies and roaming agreements 802 16 Washington University in St Louis 802 11 CSE574S 14 6 802 3 2010 Raj Jain IEEE 802 21 Features Network Selection Allows users to select between 802 3 802 11 802 16 3GPP 3GPP2 networks MS can automatically connect to the right network by observing user selections or by user policies MS can notify user when available networks change or a switch occurs Session Continuity Allows make before break handovers Open Interface for Link state event reporting Intersystem information service Handover control command service Washington University in St Louis CSE574S 14 7 2010 Raj Jain IEEE 802 21 Goals and Non Goals Goals Architecture to enable low latency handover across multiple technology access networks Help in handover decision making Standard functions to help gather network characteristics Standard command procedures for seamless handovers Supports both station initiated and network initiated handovers Non Goals Define handover policies Specify network selection procedure Execute handover Network detection procedure Washington University in St Louis CSE574S 14 8 2010 Raj Jain 802 21 Concepts Point of Access PoA Base Station or Access Point Mobile Node L2 Trigger Layer 2 events Radio Access Technology RAT 802 11 802 16 Washington University in St Louis CSE574S 14 9 2010 Raj Jain MIH Services Event Service Delivers triggers on events e g link up link down new link available Command Service Set of standard commands for handover control e g Switch Link Configure Link Initiate handover etc Information Service Defines a service that provides information for faster handovers e g list of available networks IP version network operator etc MIH users access these services using well defined service access points SAPs Washington University in St Louis CSE574S 14 10 2010 Raj Jain Event Service Local terminal side and remote network side events are supported User preferences determine the delivery of events Events may trigger user actions Layer 3 MIH Event MIH Link Event Layer 2 Washington University in St Louis Layer 3 Layer 3 MIH Event MIH Remote MIH Event Layer 2 CSE574S 14 11 MIH Link Event Layer 2 2010 Raj Jain Triggers Link Layer Events Link up Link Down Link Going Down Link Detected new link Link Parameters Change threshold crossing Link Even Rollback Link SDU Transmit Status Link Handover Imminent Link Handover Complete Washington University in St Louis Link Link Going Link UP Down Down Ethernet Link Up Link Switch 802 11 Time CSE574S 14 12 2010 Raj Jain Command Service Commands flow from user to MIH and then to link layer Commands allow users to switch links User communicates separately with each technology Commands do not flow from one technology to another Layer 3 MIH Command MIH Link Command Layer 2 Washington University in St Louis Layer 3 Layer 3 MIH Command MIH Remote MIH MIH Command Link Command Layer 2 CSE574S 14 13 Layer 2 2010 Raj Jain MIH Information Service Provides information about networks in a particular geographical area Information delivery via queries or by broadcast multicast Generally static information 802 21 defines what information is required Does not define how the service is accessed 802 21 Information Server 802 16 Washington University in St Louis 802 11 802 3 CSE574S 14 14 2010 Raj Jain MIH Information Service Cont Common information representation List of available networks Location of POA Operator ID Roaming Partners Cost Security QoS Capabilities emergency services IMS Washington University in St Louis CSE574S 14 15 2010 Raj Jain MIH Users L3 or Higher Mobility Protocols Info Command Event Info Washington University in St Louis LLC SAP Network 1 CSE574S 14 16 LLC SAP MIH LINK SAP MIH Function Command Event MIH LINK SAP MIH SAP MIH Services Network 2 2010 Raj Jain Network Initiated Handovers MIH Handover Initiate Suggested PoA MIH Handover Prepare current to target network MIH Handover Commit Client commits to do handover MIH Handover complete New network to old network Send all buffered packets Washington University in St Louis CSE574S 14 17 2010 Raj Jain MIHF Protocol MIHF message sent between peer entities Communicates events commands and information MAC independent messages defined in 802 21 Container for MIH messages for 802 11 defined in 802 11u Container for MIH messages for 802 16 defined in 802 16g Transport for MIH protocol defined in IETF MIPSHOP Mobility for IP Performance Signaling and Handoff Optimization Washington University in St Louis CSE574S 14 18 2010 Raj Jain 802 21 Transport CS ES IS messages are transported over L2 or L3 802 11u is defining transport of 802 21 messages over 802 11 MIPSHOP is defining transport over IP
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