Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Home’s Electrical Wiring Acts as Antenna to Receive Low-Power Sensor Data

17.09.2010
If these walls had ears, they might tell a homeowner some interesting things. Like when water is dripping into an attic crawl space, or where an open window is letting hot air escape during winter.

The walls do have ears, thanks to a device that uses a home’s electrical wiring as a giant antenna. Sensors developed by researchers at the University of Washington and the Georgia Institute of Technology use residential wiring to transmit information to and from almost anywhere in the home, allowing for wireless sensors that run for decades on a single watch battery. The technology, which could be used in home automation or medical monitoring, will be presented this month at the Ubiquitous Computing conference in Copenhagen, Denmark.

Low-cost sensors recording a building’s temperature, humidity, light level or air quality are central to the concept of a smart, energy-efficient home that automatically adapts to its surroundings. But that concept has yet to become a reality.

“When you look at home sensing, and home automation in general, it hasn’t really taken off,” said principal investigator Shwetak Patel, a UW assistant professor of computer science and and of electrical engineering. “Existing technology is still power hungry, and not as easy to deploy as you would want it to be.”

That’s largely because today’s wireless devices either transmit a signal only several feet, Patel said, or consume so much energy they need frequent battery replacements.

“Here, we can imagine this having an out-of-the-box experience where the device already has a battery in it, and it’s ready to go and run for many years,” Patel said. Users could easily sprinkle dozens of sensors throughout the home, even behind walls or in hard-to-reach places like attics or crawl spaces.

Patel’s team has devised a way to use copper electrical wiring as a giant antenna to receive wireless signals at a set frequency. A low-power sensor placed within 10 to 15 feet of electrical wiring can use the antenna to send data to a single base station plugged in anywhere in the home.

The device is called Sensor Nodes Utilizing Powerline Infrastructure, or SNUPI. It originated when Patel and co-author Erich Stuntebeck were doctoral students at Georgia Tech and worked with thesis adviser Gregory Abowd to develop a method using electrical wiring to receive wireless signals in a home. They discovered that home wiring is a remarkably efficient antenna at 27 megahertz. Since then, Patel's team at the UW has built the actual sensors and refined this method. Other co-authors are UW’s Gabe Cohn, Jagdish Pandey and Brian Otis.

Cohn, a UW doctoral student in electrical engineering, was lead student researcher and tested the system. In a 3,000-square-foot house he tried five locations in each room and found that only 5 percent of the house was out of the system’s range, compared to 23 percent when using over-the-air communication at the same power level. Cohn also discovered some surprising twists – that the sensors can transmit near bathtubs because the electrical grounding wire is typically tied to the copper plumbing pipes, that a lamp cord plugged into an outlet acts as part of the antenna, and that outdoor wiring can extend the sensors’ range outside the home.

While traditional wireless systems have trouble sending signals through walls, this system actually does better around walls that contain electrical wiring.

Most significantly, SNUPI uses less than 1 percent of the power for data transmission compared to the next most efficient model.

“Existing nodes consumed the vast majority of their power, more than 90 percent, in wireless communication,” Cohn said. “We’ve flipped that. Most of our power is consumed in the computation, because we made the power for wireless communication almost negligible.”

The existing prototype uses UW-built custom electronics and consumes less than 1 milliwatt of power when transmitting, with less than 10 percent of that devoted to communication. Depending on the attached sensor, the device could run continuously for 50 years, much longer than the decade-long shelf life of its battery.

“Basically, the battery will start to decompose before it runs out of power,” Patel said.

Longer-term applications might consider using more costly medical-grade batteries, which have a longer shelf life. The team is also looking to reduce the power consumption even further so no battery would be needed. They say they’re already near the point where solar energy or body motion could provide enough energy.

The researchers are commercializing the base technology, which they believe could be used as a platform for a variety of sensing systems.

Another potential application is in health care. Medical monitoring needs a compact device that can sense pulse, blood pressure or other properties and beam the information back to a central database, without requiring patients to replace the batteries.

The technology does not interfere with electricity flow or with other emerging systems that use electrical wiring to transmit Ethernet signals between devices plugged into two outlets.

For more information, contact Patel at 206-543-3451 or shwetak@cs.washington.edu. More information on the SNUPI project is at http://ubicomplab.cs.washington.edu/wiki/SNUPI.

Patel’s group is also presenting a system that uses electrical noise to monitor energy use in the home, which is now owned by Belkin International, Inc. through an acquisition earlier this year.

The group also will present a device, powered by water pressure changes, that can use these changes in pressure to monitor water consumption throughout the home from a single point.

All three presentations will be in the Home Infrastructure session Tuesday, Sept. 28 from 2 p.m. to 3:30 p.m. Central European time. The conference website is http://www.ubicomp2010.org/

Hannah Hickey | Newswise Science News
Further information:
http://www.uw.edu

More articles from Power and Electrical Engineering:

nachricht Patented nanostructure for solar cells: Rough optics, smooth surface
18.09.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

nachricht With Gallium Nitride for a Powerful 5G Cellular Network - EU project “5G GaN2” started
17.09.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Hygiene at your fingertips with the new CleanHand Network

The Fraunhofer FEP has been involved in developing processes and equipment for cleaning, sterilization, and surface modification for decades. The CleanHand Network for development of systems and technologies to clean surfaces, materials, and objects was established in May 2018 to bundle the expertise of many partnering organizations. As a partner in the CleanHand Network, Fraunhofer FEP will present the Network and current research topics of the Institute in the field of hygiene and cleaning at the parts2clean trade fair, October 23-25, 2018 in Stuttgart, at the booth of the Fraunhofer Cleaning Technology Alliance (Hall 5, Booth C31).

Test reports and studies on the cleanliness of European motorway rest areas, hotel beds, and outdoor pools increasingly appear in the press, especially during...

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Small modulator for big data

25.09.2018 | Information Technology

NASA's Terra Satellite glares at the 37-mile wide eye of Super Typhoon Trami

25.09.2018 | Earth Sciences

Rice U. study sheds light on -- and through -- 2D materials

25.09.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>