What's Next: Location, Location, Location

What's Next: Location, Location, Location

by Tim Kridel

With data rates of 100 Mb/s or more, ultrawideband (UWB) wireless sounds like a potential fit for bandwidth-intensive AV applications such as high-definition (HD) video, and it is. But UWB also can locate people and objects, an ability that sets the stage for additional pro AV applications.

One example is taking shape at Graz University of Technology in Austria. Researchers in the school's Institute of Computer Graphics and Vision are using UWB for "augmented reality" (AR): a real-world environment enhanced by computer-generated graphics, sounds, and smells. Graz University is using UWB to track AR users in order to update their virtual surroundings as they move about. "Knowing the accurate position and orientation of a mobile user is the key to doing the overlay of virtual information over the real-world video stream properly," says DI Gerhard Schall, a Graz University researcher.

Big pipe
UWB uses brief pulses of energy to transmit data at speeds of 100 Mb/s or more. That Morse code-like approach also makes the UWB signal more resistant to physical obstructions, such as walls. UWB's name comes from the way that it spreads a signal over a far wider swath of spectrum — hundreds of Megahertz — than other wireless technologies do.

UWB has a range of about 30 feet, although it can be tweaked to cover larger areas. (The actual distance depends on the amount of power that regulators allow in a particular country.) It can also be souped up to support throughput of up to 2 Gb/s.

Tag, you’re it
UWB also can be used to locate people and objects via techniques such as triangulation, where multiple sensors around a room essentially compare notes about the wireless signals to pinpoint the location of a UWB tag. "UWB is fairly accurate, with resolution on the order of 6 inches," says Henning Schulzrinne, a Columbia University professor and chair of its Department of Computer Science. "It's hard to find other technologies that can approach that level of accuracy."

Follow me
Another benefit of UWB is that it doesn't require a clear line of sight between the tag and sensor. That robustness provides more flexibility for the integrator designing the system and for the people using it. "It's possible to track an object or person through or around smaller or thinner physical obstructions," says Graz University's Schall. "If, for example, the UWB tag is occluded by the user's body, the tag still can be tracked. For the UWB system, there's no strict need for direct line of sight, which isn’t the case when using infrared tracking systems."

Granularity is good
Ubisense is already targeting applications such as interactive museum exhibits with its UWB-based Real-Time Location System (RTLS) product. "We can tell if a person is in front of an exhibit or, if it’s a large exhibit, which area of the exhibit they’re in," says Jay Cadman, the company's vice president of global marketing. "This enables applications that have a greater granularity of understanding about a person's locations and movements throughout a space, rather than being able to tell if a person is simply inside a particular room."

The more granular a location technology is, the wider the range of AV applications that it can support. "By knowing exact locations, the quality of the experience and the educational value is dramatically increased," Cadman says. "For example, if I know a person spent more time in an exhibit viewing a particular product, I can tailor additional information that person receives to be related to that particular product or line of technology. This greatly enhances the customer experience."

Granularity also can span three dimensions, such as whether a person is on a particular level of a large room. That’s the case with the Ubisense technology that Graz University is using for its AR research.

Making the business case
UWB could be a good fit for AV applications that require both precise location information and a high-bandwidth pipe — an ability that Ubisense is working on.

"In the future, we anticipate having a tag that has integrated communications as well as location," Cadman says. "This would allow us to provide to our partners and OEMs not just precise location information, but also a means of high-bandwidth data communications."