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Tiny Sensors That Can Track Anything

"Wireless sensors have moved out of the labs," said Intel spokesman Kevin Teixeira. "The technology is being figured out."

Researchers said the devices, also known as "motes," can include any number of sensors to track activity or assess the surrounding circumstances, such as weather, light and heat. When the devices collect meaningful information, their systems turn on a low-power transmitter and broadcast the data to the next closest device, up to about 100 feet away. Researchers and analysts claim the devices can sometimes operate for up to three years on a pair of double-A batteries.

If one device in the network fails, the data are picked up by another one, an echo of the sort of redundancy that makes the Internet so reliable. Dust Networks officials call it "smartmesh." They say their software is designed to enable a central PC or laptop to fuse or triangulate reports of the same activity from different angles within the network. In doing so, they said, the network can determine with far more nuance the direction a person is moving, the weight of a vehicle or even the likelihood that a machine is failing.

"This is no longer futuristic. This is real deployment for real customers," said Kris Pister, an electrical engineering and computer science professor at Berkeley who began studying smart dust in 1997. He founded Dust Networks two years ago. "It's a huge threshold to have a product we can actually shop to customers."

Researchers still face formidable technological challenges. Communication can be disrupted by hills or electrical interference. Developers have to figure out how to ensure the increasingly tiny machines don't burn through their meager power supplies too quickly, or overwhelm the networks with false alarms. In addition, the devices can still cost hundreds of dollars, scaring away some potential customers.

But analysts said they're making progress. In 2002, researchers from the Intel Research Laboratory at Berkeley linked 32 sensors about the size of a prescription bottle to the Internet to take readings of the weather on Great Duck Island, Maine, and to assess the condition of nesting burrows used by local seabirds known as Leach's storm petrels. In the second season last year, they used more than 150 second-generation sensors that were smaller than size D batteries.

"These networks monitor the microclimates in and around nesting burrows used by the Leach's Storm Petrel," said a report on the project. "Our goal is to develop a habitat monitoring kit that enables researchers worldwide to engage in the non-intrusive and non-disruptive monitoring of sensitive wildlife and habitats."

In August, two dozen Dust sensors were installed in a Supervalu grocery store in suburban Minneapolis. That network is monitoring temperatures and energy use, which typically accounts for the second-largest cost of operating a grocery store.

As for SAIC, it's adopting "smartmesh" sensor networks to create electronic perimeter systems for defense and intelligence customers. Thomas J. Sereno Jr., manager for the SAIC monitoring systems division, said tests found the technology can use small magnetometers to detect whether someone is carrying a gun. SAIC plans to use microphones to search for "acoustic signatures" of vehicles, moving groups of people and such. Sereno said it also will build in cameras of the sort used in mobile phones.

Sereno speculated that some SAIC clients may use unmanned airborne vehicles to fly over rugged and dangerous environments and deposit the technology. SAIC will also be pitching it for homeland and border security. He said the ability of the network to be "self-healing" if some of the devices fail is appealing. The company intends to unveil a model for customers next month.

"If you combine all the information from these sensors and fuse it, you can make inferences," he said. "We're starting to get the firm belief this is truly going to work."

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