COLLOQUIUM
Department of Computer Science and Engineering
University of South Carolina
 
Client-Centered Energy Savings for TCP Downloads

David Lowenthal

Department of Computer Science
University of Georgia

Date: August 6, 2004 (Friday)
Time: 3:30-4:30PM
Place: Swearingen 1A03 (Faculty Lounge)

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.  Results show that our scheme can save significant WNIC energy
with only a modest increase in the transmission time.

David Lowenthal is an associate professor in the Department of
Computer Science at the University of Georgia.  His research interests
are in parallel and distributed computing and mobile computing.  He is
also interested in energy issues for a broad range of systems, from
handheld and laptops to supercomputers.  Dr. Lowenthal received his
M.S. in 1992 and his Ph.D. in 1996 from the University of Arizona,
where he worked on the Filaments project. He also holds a B.S. degree
from the University of California, Davis.