Electrical Engineering and Computer Science

Prabal Dutta Wins IPSN Best Paper Award   Bookmark and Share



Assistant Professor Prabal Dutta, along with colleagues Thomas Schmid (Postdoctoral Scholar, UCLA EE) and Mani Srivastava (Professor, UCLA EE), has won a Best Paper Award at the 9th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN'10), which takes place April 12-16, 2010, in Stockholm, Sweden, as part of Cyber-Physical Systems Week.

The paper, entitled "High-Resolution, Low-Power Time Synchronization an Oxymoron No More," shows how it is possible to build a power-proportional time synchronization service that offers a baseline power draw of a low-speed clock (e.g. 32 kHz crystal), but provides the time resolution that only a higher frequency clock could offer (e.g. 8 MHz crystal), and scales essentially linearly with access (i.e. the "reading" and "writing" of the clock).

The researchers achieved this performance by revisiting a basic assumption in the design of time-keeping systems – that to achieve a given time-stamping resolution, a free-running timebase of equivalent frequency is needed. They showed that this assumption is false and instead that the dependence is not on usage (i.e., whether on or off) but rather on access (i.e., reading and writing). Therefore, it is possible to duty cycle the free-running timebase itself, and augment it with a lower-frequency, temperature-compensated one, which achieves comparable resolution, at a fraction of the power, for typical workloads. The key technical challenge lies in duty cycling the fast clock and synchronizing the fast and slow clocks. Their results show power-proportional operation with a 10x improvement in average power over the state-of-the-art and a synchronization accuracy exceeding 1 microsecond at duty cycles below 0.1%.

Prof. Dutta's research interests straddle the hardware/software interface and include systems, networking, and architecture. Recent focus areas include energy management, wireless networking, and embedded systems. He is also interested in emerging mobile sensing, building-scale sensing, and healthcare applications that cut across all of these areas.


Posted: April 14, 2010