UWB Brings Greater Precision to RTLS

By Jeff Goldman

December 20, 2007

Ultrawideband can be used to track an item’s location within a radius of 12 to 36 inches.

Real time location systems (RTLS) using Wi-Fi are becoming increasingly commonplace, particularly in the healthcare industry, with the market currently being led by Ekahau, AeroScout and PanGo. But RTLS isn’t limited to Wi-Fi and proprietary technologies: a few companies are now offering positioning systems using ultrawideband (UWB), with interesting results.

MSSI introduced the second generation of its Sapphire DART UWB RTLS system in October of 2006; Ubisense launched its Series 7000 solution in August of this year; and Time Domain announced its Precision Location UWB System (PLUS) earlier this month. Other companies offering UWB RTLS solutions include Aether Wire & Location and SandLinks.

Greg Clawson, vice president of sales and marketing for Time Domain, says the company first developed the PLUS system in response to customer requests. About 18 months ago, he says, Time Domain started getting inquiries seeking a solution that could offer more precise positioning than Wi-Fi or proprietary technologies.

The result is a system with an accuracy of one to three feet, while Wi-Fi-based RTLS can generally determine location within a radius of three to 20 feet. Clawson says installations of RTLS over Wi-Fi are “leaving a lot of people scratching their heads, saying, ‘Okay, I kind of like it, but it’s not quite precise enough for what I need.’” And so they turn to UWB.

At the same time, it’s not just about precision.

“It also works great in a highly metallic environment, like manufacturing or a hospital—and it works when you have thousands of tags that need to be read simultaneously, which the other technologies can’t do,” Clawson says.

The system uses antennas that look like 2’ x 2’ ceiling tiles, and Clawson says the installation process is relatively straightforward.

“Regular network installers with a little bit of training can get it up and running, calibrate it, and tie it into their applications… and within a couple of weeks, they’re tracking hundreds or thousands of items within 12 to 36 inch accuracy,” he says.

Alternatively, Clawson says, you can simply deploy a single standalone reader.

“It can monitor a radius of 150 feet around it and just tell you proximity—which is generally what the other technologies do anyway—except it can monitor 5,000 or 6,000 tags simultaneously,” he says.

And, while Clawson admits you’ll pay a premium for the higher volume and greater precision, he says the price isn’t prohibitive.

“When you look at cost per square foot of coverage, you’re definitely below $10 a square foot, even in the worst case scenario, to get the highest precision,” he says.

Early implementations of the PLUS system include a deployment at the 240-bed Nesconset Nursing Center to monitor patient safety and security, as well as at the 926-bed Washington Hospital Center for asset tracking in partnership with Parco Wireless.

And a number of additional deployments are already in the works, Clawson says—not only in healthcare, but also in manufacturing and retail.

“We’re just getting started,” he says. “We’re going to have a lot more announcements in the coming months.”

Jeff Goldman is a freelance writer and photographer based in Los Angeles, California. In addition to his work for Wi-FiPlanet, he writes for Jupitermedia's ISP-Planet, UWB Planet, and VoIP Planet. He blogs about the wireless industry at Wireless Weblog.



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