* Ubicomp 2010 Best Paper Award
ElectriSense: Single-Point Sensing Using EMI for Electrical Event Detection and Classification in the Home, Sidhant Gupta, Matt Reynolds, Shwetak Patel.
ElectriSense is a new solution for automatically detecting and classifying the use of electronic devices in a home from a single point of sensing. It relies on the fact that most modern consumer electronics and fluorescent lighting employ switch mode power supplies (SMPS) to achieve high efficiency. These power supplies continuously generate high frequency electromagnetic interference (EMI) during operation that propagates throughout a home’s power wiring. We show both analytically and by in-home experimentation that EMI signals are stable and predictable based on the device’s switching frequency characteristics. Unlike past transient noise-based solutions, this new approach provides the ability for EMI signatures to be applicable across homes while still being able to differentiate between similar devices in a home. We have evaluated our solution in seven homes, including one six-month deployment. Our results show that ElectriSense can identify and classify the usage of individual devices with a mean accuracy of 93.82%.
* Ubicomp 2010 Best Paper Honarble Mention
SNUPI: Sensor Nodes Utilizing Powerline Infrastructure, Gabe Cohn, Erich Stuntebeck, Jagdish Pandey, Gregory D. Abowd, Brian Otis, Shwetak Patel
The SNUPI paper presents the design and implementation of small ultra-low-power 27 MHz sensor nodes that transmit their data by coupling over the powerline to a single receiver attached to the powerline in the home. We demonstrate the ability of our general purpose wireless sensor nodes to provide whole-home coverage while consuming less than 1 mW of power when transmitting (one order of magnitude lower than existing nodes), and our custom CMOS transmitter consumed only 65 ?W (two orders of magnitude lower than existing nodes). This is the lowest power transmitter to date compared to those found in traditional whole-home wireless systems. (See earlier media coverage here.)