Issue No. 03 - March (2014 vol. 13)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TMC.2013.8
Ahmad Rahmati , Broadcom Corporation, Sunnyvale
Clayton Shepard , Rice University, Houston
Chad C. Tossell , USAF Research Laboratory, Wright-Patterson Air Force Base, OH
Lin Zhong , Rice University, Houston
Philip Kortum , Rice University, Houston
Angela Nicoara , Deutsche Telekom Silicon Valley Innovation Center, Mountain View
Jatinder Singh , Stanford University, Stanford
Is it possible to migrate TCP/IP flows between different networks on modern mobile devices without infrastructure support or protocol changes? To answer this question, we make three research contributions: 1) We report a comprehensive characterization of IP traffic on 27 iPhone 3GS users for three months. 2) Driven by these findings, we devise two simple, effective, and easily deployable system mechanisms to support seamless flow migration without network support, and extensively evaluate their effectiveness using our field collected traces of real-life usage. Wait-n-Migrate leverages the fact that most flows are short lived. It establishes new flows on newly available networks but allows preexisting flows on the old network to terminate naturally. Resumption Agent takes advantage of the resumption functionality of modern protocols to securely resume flows without application intervention. Combined, they provide an unprecedented opportunity to immediately deploy policies that leverage multiple networks to improve the performance, efficiency, and connectivity of mobile devices. 3) We report an iPhone-based implementation of these system mechanisms and demonstrate their overhead to be negligible. Furthermore, we employ a sample switching policy, AutoSwitch, to demonstrate their performance. Through traces and field measurements, we show that AutoSwitch reduces user disruptions by an order of magnitude.
Switches, Electronic mail, Ports (Computers), Protocols, IEEE 802.11 Standards, Smart phones, IP networks
A. Rahmati et al., "Seamless TCP Migration on Smartphones without Network Support," in IEEE Transactions on Mobile Computing, vol. 13, no. 3, pp. 678-692, 2014.