An example of a low-powered sensing device, capable of sending wireless signals to a home electrical system, acting as an antenna. (Photo: University of Washington, Gabe Cohn.)

Looks like our homes are smarter than we knew.

Researchers at the University of Washington and Georgia Tech have figured out how to use the common electrical wiring in residential walls as giant antennas to receive wireless signals from all sorts of sensors. The discovery could enable efficient systems for collecting a variety of data in the home -- from room temperature and air quality to light level and even human health.

The UW is spinning out a company to commercialize a base station that will leverage the approach and serve as a platform for a variety of sensors and applications. Those involved in the as-yet-unnamed startup include Shwetak Patel, the principal investigator on the project. Patel is the 28-year-old UW assistant professor of computer science and electrical engineering who sold another startup to Belkin in April.

The latest project is dubbed SNUPI, which stands for "Sensor Nodes Utilizing Powerline Infrastructure." The key is that using the home wiring system as an antenna allows the sensors themselves to consume far less energy, letting them run for freakishly long periods of time, stretching into decades, on a watch battery.

The project is being presented this month at the Ubiquitous Computing conference in Copenhagen, Denmark. Here's the research paper for further reading: PDF, 10 pages. An excerpt:

The use of the powerline as a receiving antenna offers a number of advantages because its length makes it an ideal receiving antenna at low frequencies (10–40 MHz). First, this allows us to greatly reduce the power output of the radio, while still achieving a practical communication range. Second, the efficiency of the powerline antenna, allows us to reduce the size of the antenna on the sensor node itself (see Figure 1), despite it having to operate at lower frequencies where ideal antennas are prohibitively large. Finally, only a single powerline-connected base station receiver is needed for whole-home coverage, thereby reducing the installation time by an end-user.

See this UW article for a more detailed description of the technology.