Wednesday, May 11th, 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