Research Magazine 2006

Wireless system tracks people in real time

You’re a fire department battalion chief on the site of a four-alarm apartment fire. Firefighters are inside, extinguishing the blaze and searching for people who may be trapped. More firefighters are at various locations outside the complex and in adjacent buildings.

Wouldn’t it be nice to know exactly where everyone was in case the situation quickly deteriorated?

Researchers in the Computer Science and Engineering Department are working on something that would let the chief do just that. Led by Assistant Professor Gergely Zaruba and assisted by Professor Farhad Kamangar, Assistant Professor Manfred Huber and Senior Lecturer David Levine, the researchers are developing an inexpensive wireless mesh sensor network to track small, battery-powered tags.

“This is an ‘active’ system, not like ‘passive’ RFID, which requires a nearby, outside source to activate the signal,” Dr. Zaruba explains. “With their self-contained power source, our tags can send out powerful signals that can be detected over greater distances.” 

The team is evaluating a prototype system on campus. Early results have shown signals received from distances greater than half a mile outside and 200-300 feet indoors. Relays outside and inside a building or in an underground labyrinth such as a coal mine would enable the signals to be tracked from even greater distances.

Tracking the tags is made possible through a combination of inertial navigation systems inside the tags and by measuring signal strength received at various access points (antennas). These will accurately locate the tag, and the person wearing it, within a 1-meter area.

The tags could give the location of people in environments where real-time information is important, like hospitals, military actions and search-and-rescue missions.






— Roger Tuttle