Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks1 Enhancing IP Mobility Handover Management toward Future Internet Koshiro Mitsuya Graduate School of Media and Governance, Keio University WIDE Project (InternetCAR, Nautilus proj.)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks2 Outline Introduction of new handover concepts Flow-oriented smooth handover management Result of the proving test (InternetCAR testbed)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks3 Background Deployment of ubiquitous and heterogeneous wireless access networks Wi-Fi, WiMAX, HSDPA, etc. Overlapped wireless networks Multihomed Mobile node equipped with several network interfaces switches between or simultaneously uses these interfaces Proposition Maximally enhance the end-system to obtain the best possible connectivity in such Multihomed Mobile Internet

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks4 Handover by definition The process of switching the point of attachment (either L2 or L3) to the Internet appli. IP Transport appli. NIC AP AR

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks5 New Handover Concepts Per-flow Handover Each packet determines which path (interface) should be used to transmit the packet Policy-enabled Handover The decision is the results of the comparison of the network conditions with user demand Seamless Handover The decision dynamically changes due to e.g. the mobility Switching without service interruption is required Adaptive Handover The switching also causes network conditions to change drastically Some degree of adaptation (e.g. bandwidth smoothing) improves the user experience

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks6 Discussion Issue 1: Roaming between cell without service interruption (seamless horizontal handover) IP Mobility (MIPv6, NEMO) To support traditional applications Upper layer mobility requires applications to be modified Problems: delay for L2 handover(A), L3 configuration(B,C,D), and CoA registration(E)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks7 Discussion (cont.) + Fast Handovers (FMIPv6) There are many optimizations (below) but only FMIPv6 optimize (B,C,D) at once L2 handover, L3 configuration, CoA registration, F-HMIPv6 Open issue: We cannot avoid packet loss due to the single CoA limitation Inter-layer instructions is necessary to perform the fast handover Link layer information is media dependent

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks8 Discussion (cont..) Issue 2: Roaming between different network interfaces (per-flow handover and policy-enabled handover) IP Mobility (MIPv6, NEMO) MIPv6 only allows to register a single CoA per HoA It results in the hard handover Multihoming Extension (MCoA) Allow to register multiple CoA No other standard exists Open Issue: No mechanism to distribute traffic among available paths No mechanism to maintain the policy

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks9 Discussion (cont..) Issue 3: Path switching is happened often due to the mobility, and it causes network condition to change drastically Network Condition Adaptation can be implemented at several layers Transport: dynamic renegotiation of connection parameters Session: RSTP, RTP Application: bandwidth smoothing, effective compression Open Issue: Each optimization technique solves a specific problem so that a combination of several optimizations are required Each technique independently acquires the link layer info. hence it is hard to integrate them

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks10 Flow-oriented Smooth Handover Management Concept Separation of Path Maintenance and Flow Distribution Separation of Path Maintenance and Flow Distribution Path Maintenance IP path establishment for each interface API to transparently use the IP paths Flow Distribution Path selection Flow distribution Policy management

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks11 Flow-oriented Smooth Handover Management Concept (cont.) + Handover Services Defines a set of primitives to assist handover operations Events (LinkUp, LinkDown, etc.) Commands (LinkConnect, etc.) Each protocol solves a specific problem so that a combination of protocols is efficient to maximally enhance the performance Inter-layer or Inter-node interactions The standard (abstracted) primitives help the integration

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks12 MNNCNMRPARNAR send L2 status update receive NAR info (L2/L3, QoS results) perform L2 handoff Handover Complete Notification Handover Notification (pre-notification of link characteristics) make a handover decision - decide NAR - make L2/L3 QoS reservation Voice+Audio Voice only Fast Handoff(few ms) Adapted to the change of bandwidth dynamically & surely Example System Flow Keep old binding cache for a while

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks13 System Diagram L2 Abstraction IP Mobility MIPv6, NEMO Optimizations FMIPv6 (with proposed binding cache mngmnt) Multiple Care-of Address Flow Distribution Adaptive Application Inter-layer information exchange

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks14 Flow Distribution Policy (draft-mitsuya-monami6-flow-distribution-policy) List of available HoA/CoA pair A HoA/CoA pair

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks15 Example

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks16 L2-LinkStatus Acquisition request for the current link status. L2-PeerList Acquisition request for the list of possible access points. L2-PeerFound / L2-PeerLost Indication of discovery/missing of candidate access points. L2-PeerStatus QoS related information about a peer L2-LinkUp / L2-LinkDown Notification that a new link is up / an connected link is down. L2-LinkStatusUpdate Notification changes in the status of the connected link. L2-LinkConnect / L2-LinkDisconnect Request for connection/disconnection of the specific link. L2 Primitives (draft-irtf-mobopts-l2-abstractions) * IEEE WG refer our works

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks17 L3 L2 Time L2-LinkTo BeDown L2-LinkConnectL2-LinkUp L2 Handover L3 Handover Preparation L3 Handover RtSolPr Mobile Node Previous AR New AR HI FBack FNA L2-PeerList L2-PeerFound/Lost L2-PeerStatus AP/AR Discovery FBU PrRtAdv HAck Packets FMIPv6 (predictive mode) with L2 Primitives

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks18 1 packet lost due to L2 handover 1 packet lost due to L2 handover 64kbps traffic 80Byte payload packet 10msec Horizontal Handover Performance (against G.711 VoIP traffic) a, WEP, same channel

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks19 Vertical Handovers with L2 Primitives (A)L2-LinkStatusUpdate-A, (B) L2-LinkStatusUpdate-B, (C ) L2-LinkDown, (D) L2-Connect, (E) LLinkDisconnect Proposed

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks20 IPv4 Internet iBurst Networ k iBurst Networ k KDDI/A U Network KDDI/A U Network In-vehicle Experiment Testbsd MR HUB SIP server VoIP Client Log Analyzer Mobile Network iBurst UT EVDO W01K Kyocera R&D Center Keio Campus VoIP Client IPv6 Internet HA DTCP server G729(20bytes per 20ms) traffic dump L2 info trace VoIP clients are communicating via a MR the MR is equipped with iBurst and EV-DO the MR will switches from iBurst to EVDO

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks21 RSSI History and Link Event (Make-After-Break Handover)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks22 Received VoIP Traffic (Make-After-Break Handover) 37s160s If there is no inteaction, the performance is just terribule

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks23 RSSI History and Link Event (Make-After-GoinToBreak Handover)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks24 Received VoIP Traffic (Make-After-GoingToBreak Handover) 16.9s L2 and L3 configuration takes looong time

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks25 RSSI History and Link Event (Make-Before-Break Handover)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks26 Received VoIP Traffic (Make-Before-Break Handover) 350ms Predictive metho (e.g. pre-configuration) is efficient Packet loss is still observed because of the phased bandwidth allocation algorithm Predictive metho (e.g. pre-configuration) is efficient Packet loss is still observed because of the phased bandwidth allocation algorithm

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks27 RSSI History and Link Event (Multihomed Make-Before-Break HO)

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks28 Received VoIP Traffic (Multihomed Make-Before-Break HO) 0ms, no packet loss

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks29 Adaptive Video Conference Cellular IEEE802.11b Changing the video encoding rate dynamically

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks30 Conclusion Flow-oriented Handover Management + Media Independent Handover Service Successfully developed the new end-system architecture that enables each application to roam seamlessly and adaptively between ubiquitously deployed networks Future work QoS guarantee Power management

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks31 Thank you for your listening!

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks32

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks33 Key Contribution Handover Service Defined the abstracted link layer events and commands for the persistent IP path maintenance Defined the abstracted link layer events and commands for the flow migration FMIPv6 related Modified the specification on the binding management Extended FMIPv6 protocol to carry other information needed for handover optimization Provided the worlds first open source implementation of FMIPv6 Feedback to the spec, Interoperability tests, Demonstrations

Feb. 21, 2008AsiaFI School on Mobile and Wireless Networks34 Key Contribution (cont.) Flow Distribution Defined the policy language to describe user demands for the flow distribution Developed the policy exchange protocol among end and anchor nodes of communications Network Condition Adaptation Developed a protocol to share the network condition among end and anchor nodes of communications