Home without Wires
The FCC’s February decision allows the commercialization of ultrawideband on an unlicensed basis-the same arrangement under which technologies like cordless phones and wireless data networks such as Bluetooth and 802.11b operate. The good news here for companies deploying ultrawideband systems is that they will not have to pay for the spectrum their technology uses. The bad news is that to assuage licensed service providers (like cell phone companies) who fear that ultrawideband might interfere with their slices of the radio spectrum, the FCC put strict limits on the new technology. Consumer ultrawideband radios are permitted to transmit only very feeble signals, at one-thousandth the power that personal computers are allowed to radiate just by being on, and only in specific frequency ranges: below 960 megahertz, between 3.1 and 10.6 gigahertz, and between 22 and 29 gigahertz. Practically, this means that the new radios will be limited in either the distance they can transmit or the data rates they can achieve..But even within those constraints, one of the technology’s most promising applications might well have room to blossom. Ultrawideband could serve as a near ideal medium for short-range
“personal-area networks” that connect electronic devices. This concept is already embodied in the communications standard known as Bluetooth. But ultrawideband radios will be like “Bluetooth on steroids,” says Martin Rofheart, XtremeSpectrum’s cofounder and CEO.
For one thing, ultrawideband will be a lot faster than its rival-capable initially of transmitting 100 megabits per second across a distance of 10 meters, or about 100 times Bluetooth’s speed. That makes ultrawideband suitable for connecting devices like camcorders and TVs or computers and peripherals-applications requiring more bandwidth than Bluetooth can deliver. XtremeSpectrum, for example, has built a prototype that simultaneously sends DVD-quality audio and video across a room from player to TV. The system, cited as “best wireless technology of 2002” at the Wireless Systems Design conference in San Jose, CA, sends data from as many as four players to four television sets. Such a hookup could potentially distribute different cable television signals to multiple TVs in a home. That’s an application that has lured AT&T into studying the technology as well. “There are a lot of benefits,” says wireless researcher Saeed Ghassemzadeh of AT&T Labs-Research-not least of which would be the elimination of the cost of materials and labor to wire multiple access points around a house or apartment.
The same broadband-data capabilities could also make ultrawideband a wireless replacement for the cables that connect computers with peripherals like printers and scanners. Intel began an ultrawideband research project about two years ago and is considering the technology’s potential to replace the newest version of the Universal Serial Bus (USB) standard, which transmits data at 480 megabits per second via cables. Both XtremeSpectrum and another ultrawideband company, Time Domain of Huntsville, AL, aim to reach data rates of 400 to 500 megabits per second within the next year. And Pulse-Link’s Watkins says that by year’s end his company hopes to be making prototypes that approach speeds of one gigabit per second for distances up to 10 meters-faster than Ethernet and other current wired connections. Within three to five years, Watkins adds, Pulse-Link will build devices that transmit data much farther-50 to 100 meters-and at speeds 10 to 50 times faster than today’s 802.11a and 802.11b wireless networking technologies.
But the technology’s real strengths go beyond wireless data transfer. Walter Hirt, ultrawideband-project leader at IBM’s research lab in Zrich, says ultrawideband is exciting because it offers the ability to combine data transmissions with location information in a way other wireless technologies cannot.
Three ultrawideband outfits, for example-ther Wire and Location in Nicasio, CA, Israeli company Pulsicom and Multispectral Solutions-are developing systems of extremely high precision to track people and objects in real time. Small transceivers attached to merchandise would allow stores to accurately track, retrieve and catalogue inventory in warehouses and storerooms; the tracking systems would also monitor against theft. Multispectral Solutions has already built a system for the navy that it hopes to apply to retail shipping and warehousing problems. Hospitals, meanwhile, could use the technology to quickly run down equipment and people in emergencies.
ther Wire also hopes to combine GPS receivers with ultrawideband for positioning systems. GPS, which works best outdoors, would locate an object to within a few meters; then a local ultrawideband infrastructure would pinpoint location to within a few centimeters-even indoors. In the short term, pager-sized versions of the technology could be used for public safety applications like tracking firefighters in a burning building; such devices could transmit temperature, oxygen levels and vital signs to the fire marshals outside. “In an emergency situation, you need to know where people are,” says ther Wire cofounder Robert Fleming. “When you have guys in buildings, you can’t see where people are. Your own guy could be six inches away, across the next wall.” Ultimately, the company envisions systems so cheap that parents could slap sticky ultrawideband tags on their kids to keep tabs on them in malls or theme parks.
Collision avoidance radars-like the one built by Fontana’s Multispectral Solutions-are another ultrawideband strength. Initially built to sense the proximity of obstacles to unmanned aerial vehicles, such systems could serve as backup sensors in cars. DaimlerChrysler has already built a prototype car that couples an ultrawideband-based collision avoidance radar with controllers that gently engage the brakes if the vehicle appears to be heading for a crash. “It’s extraordinary driving it, because as your foot is on the gas and you’re backing up towards a pole, even though your foot is on the gas, the car comes to a gradual stop,” says Tim McBride, who helped DaimlerChrysler push for FCC approval of ultrawideband as the company’s vice president of Washington affairs. McBride says that, with the necessary approvals, cars incorporating the system could be on the road within the next few years.
Ultrawideband companies hope to establish markets for both types of applications quickly. This year, both Time Domain and XtremeSpectrum released their first ultrawideband chips, which electronics makers like Sony (a Time Domain investor) could incorporate into consumer products like TVs, camcorders, computers and stereos. XtremeSpectrum’s Rofheart expects to see ultrawideband radios in high-end consumer electronics (like plasma screen TVs) by late 2003. He says that the wireless links may start appearing in mass-market products a year later.