May 11, 2005 —
"Wireless sensor networks are expected to operate for months, if not
years, on small inexpensive batteries with limited lifetimes," begins
this year's EE best student paper, by Ph.D. candidate Gang Lu.
Lu, who expects to defend his thesis at the end of this summer, was the
lead author of a study setting forth a strategy for optimizing the
conflict between energy conservation and speedy communications.
Lu says that the way to save batteries is for individual units to go to
sleep for part of the time. The challenge is deciding when and
for how long units should sleep while still guaranteeing that the
sensor array sends a message with minimal delay.
Attacking the problem in abstraction, Lu's paper proved that an
optimal, general solution to the problem is computationally
intractable..
But by adopting specific architectures ("rings," and "trees"), Lu and
co-authors Narayanan Sadogopan and Bhaskar Krishnamachari of USC, and
Ashish Goel of Stanford found some optimal solutions. They also
discovered through simulations that simple adjustments in wake-up
scheduling over a network could significantly cut communications delay
without affecting energy efficiency.
The paper appeared in IEEE Infocom 2005, a prominent and highly competitive conference
in the area of communication networks.
A native of Xiang Fan in China's Hubei Province, Gan received his B.S.
from the University of Science and Technolgy of China in Hefei, and his
M.S. from the Chinese Academy of Science.
He has been at USC since Spring, 2001, and is a member of the
Autonomous Networks Research group led by Assistant Professor
Bhaskar Krishnamachari. The ANR website is at
http://ceng.usc.edu/~anrg
