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USHA: A Practical Vertical Handoff Solution

USHA: A Practical Vertical Handoff Solution. Ling-Jyh Chen, Tony Sun, Mario Gerla Computer Science Department, UCLA. Mobility. USHA: A Practical Vertical Handoff Solution. Introduction. The emerging network applications Wireless & Mobility Multiple network interfaces.

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USHA: A Practical Vertical Handoff Solution

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  1. USHA: A Practical Vertical Handoff Solution Ling-Jyh Chen, Tony Sun, Mario Gerla Computer Science Department, UCLA

  2. Mobility USHA: A Practical Vertical Handoff Solution Introduction • The emerging network applications • Wireless & Mobility • Multiple network interfaces MSAN 2005

  3. USHA: A Practical Vertical Handoff Solution Handoff A seamless handoff is defined as a handoff scheme that maintains the connectivity of all applications on the mobile device when the handoff occurs. Challenges: maintaining application sessions (e.g. TCP) MSAN 2005

  4. USHA: A Practical Vertical Handoff Solution Seamless Handoff • Two goals: low latencies and few packet losses • Related Work • Network Layer Approaches • MIPv4, IPv6 • Upper Layer Approaches • End-to-End Approaches (e.g. Dynamic DNS) • New Session Layer Protocols (e.g. MSOCKS) • Transport Layer Protocols (e.g. TCP-MH and SCTP) Question: Which one are you using? MSAN 2005

  5. USHA: A Practical Vertical Handoff Solution Universal Seamless Handoff Architecture • USHA: a “simple” and “practical” handoff solution. NAT server NAT Server All packets are encapsulated and transmitted using UDP Applications are bound to the tunnel and transparent to the handoff. MSAN 2005

  6. USHA: A Practical Vertical Handoff Solution Experiment Scenario (1) • Indoor mobility: Ethernet & 802.11b MSAN 2005

  7. USHA: A Practical Vertical Handoff Solution Experiment (1): LOW_to_HIGH MSAN 2005

  8. USHA: A Practical Vertical Handoff Solution Experiment (1): HIGH_to_LOW MSAN 2005

  9. USHA: A Practical Vertical Handoff Solution Experiment Scenario (2) • Outdoor mobility: 802.11b & 1xRTT MSAN 2005

  10. USHA: A Practical Vertical Handoff Solution Experiment (2): LOW_to_HIGH MSAN 2005

  11. USHA: A Practical Vertical Handoff Solution Experiment (2): HIGH_to_LOW MSAN 2005

  12. USHA: A Practical Vertical Handoff Solution Handoff Server Selection • k network interfaces on the mobile host • n available HS • Di,j: the round-trip delay from the i-th interface to the j-th handoff server • Ci,j: the capacity of the link from the i-th interface to the j-th handoff server MSAN 2005

  13. Detecting handoff events and performing service adaptation Transcoding according to available bandwidth and MH properties Account management and access control Traffic encryption Real-time compression Intelligent handoff: decide the “best” time and target interface to handoff USHA: A Practical Vertical Handoff Solution USHA extensions MSAN 2005

  14. USHA: A Practical Vertical Handoff Solution USHA extensions • Examples: • Traffic encryption: IPsec [6] • Real-time compression: LZO [8] • Intelligent handoff: Wang [18], Chen [ANWIRE’04] • Service adaptation: Chen [QShine’05] MSAN 2005

  15. USHA: A Practical Vertical Handoff Solution Some results of service adaptation • Vertical Handoff from LOW_to_HIGH MSAN 2005

  16. USHA: A Practical Vertical Handoff Solution Some results of service adaptation • Vertical Handoff from HIGH_to_LOW MSAN 2005

  17. USHA: A Practical Vertical Handoff Solution Conclusions • We proposed a practical vertical handoff approach, called USHA. • We evaluated USHA via a set of testbed experiments. • Future Work: • Extending USHA to support more dynamic network scenarios (e.g. MANET), in which the vertical handoff may occur on application servers, clients, and/or intermediate hosts. MSAN 2005

  18. USHA: A Practical Vertical Handoff Solution Thanks! http://www.cs.ucla.edu/NRL MSAN 2005

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