NC State University

Department of Computer Science Colloquia 2003-2004

Date:   Friday, October 3, 2003
Time:   2:00 PM (Talk)
Place:   Textiles, Room 2431, NCSU Centennial Campus (click for courtesy parking request)

Speaker:   David K. Lowenthal , Computer Science Department, University of Georgia

Client-Centered Energy Savings for TCP Downloads

Abstract:   In mobile devices, the wireless network interface card (WNIC) consumes a significant portion of overall system energy. One way to reduce energy consumed by a device is to transition its WNIC to a lower-power sleep mode when data is not being received or transmitted.

This talk discusses client-centered techniques for saving energy during TCP downloads. The basic idea is that the client predicts when packets will arrive, keeping the WNIC in sleep mode only when necessary. Furthermore, the client increases the amount of time that can be spent in sleep mode by shaping the traffic; in particular, the client convinces the server to send data in bursts rather in a smooth manner, trading lower WNIC energy cost for increased transmission time. Our technique uses client-side modifications to TCP and does not rely on any assistance from the server, a proxy, or IEEE 802.11b power-saving mode. Initial results show that while there is a modest increase in the transmission time, our scheme can save significant WNIC energy.

Short Bio:   David Lowenthal is an associate professor of computer science at the University of Georgia. He holds a B.S. in computer science from the University of California at Davis and an M.S. and Ph.D in computer science from the University of Arizona. His research interests include operating systems, parallel and distributed computing, and mobile and power-aware computing.

Host:   Vincent Freeh, Computer Science, NCSU

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