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VIP : a Virtual Interface-based aPproach for vertical handover in single-subnet networks. Wei-Cheng Xiao 1 , Ling-Jyh Chen 2 , Shih-Hsuan Tang 1 , Cheng-Fu Chou 1 1 National Taiwan University 2 Academia Sinica. Introduction. The emerging network applications
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VIP: a Virtual Interface-based aPproach for vertical handover in single-subnet networks Wei-Cheng Xiao1, Ling-Jyh Chen2, Shih-Hsuan Tang1, Cheng-Fu Chou1 1National Taiwan University 2Academia Sinica
Introduction • The emerging network applications • Multi-interface/channel/radio Technologies • Human Mobility IEEE AINA 2007
Handover A seamless handover is defined as a handover scheme that maintains the connectivity of all applications on the mobile device when the handover occurs. Challenges: maintaining application sessions (e.g., TCP) IEEE AINA 2007
Seamless Handover • 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) • Proxy-based Approaches (e.g., USHA) • New Session Layer Protocols (e.g., MSOCKS) • Transport Layer Protocols (e.g., TCP-MH and SCTP) Question: Which one are you using? Why? IEEE AINA 2007
Our Contribution • We propose a vertical handover solution, called VIP, for single-subnet scenarios. • We implement the proposed solution in Linux and perform a set of experiments on our testbed. • We show that VIP is a simple and practical vertical handover solution for single-subnet networks. IEEE AINA 2007
VIP - Architecture • VIL: a 2.5th layer solution • VI: a dummy network interface • KIS: a handover manager that determines the “best” network interface and links it to the VI IEEE AINA 2007
VIP Implementation • Implement on Linux platform • Invoke ARP updates dynamically to link MAC address of a newly selected interface to the VI to complete a vertical handover IEEE AINA 2007
VIP – Kernel Interface Selector (KIS) IEEE AINA 2007
VIP – Kernel Interface Selector (KIS) IEEE AINA 2007
VIP - Evaluation Scenarios • Linux-based laptop • Debian Linux with kernel version 2.6.12.6 • IEEE 802.11a: D-Link DWL-AG660 • IEEE 802.11b: Intel Pro/Wireless 2200BG • Access points • IEEE 802.11a: Linksys WAP55AG router • IEEE 802.11b: Buffalo WLA2-G54C router IEEE AINA 2007
VIP - Evaluation Results (L2H) • IEEE 802.11b -> IEEE 802.11a IEEE AINA 2007
VIP - Evaluation Results (H2L) • IEEE 802.11a -> IEEE 802.11b IEEE AINA 2007
VIP - Evaluation Results (H2L) • IEEE 802.11a -> IEEE 802.11b freeze period IEEE AINA 2007
VIP - Evaluation Results (H2L) • Solution for Freeze Period • Employ specialized TCP variant (e.g., Freeze-TCP [8]) • Implement other QoS enhancement schemes (e.g., Explicit Handover Notifications [9] or ERR+EHN [5]) IEEE AINA 2007
Summary • We propose a vertical handover solution, called VIP, for single-subnet scenarios. • VIP is a 2.5th layer solution that combines a virtual interface and ARP update messages to achieve vertical handovers. • VIP can run stand-alone, and thus ready for immediate real-world deployment. • Using testbed experiments, we show that VIP is a simple and practical solution for vertical handover in single-subnet networks. IEEE AINA 2007
Thanks! http://www.iis.sinica.edu.tw/~cclljj/ http://nrl.iis.sinica.edu.tw/ IEEE AINA 2007