The notion of faster, high-bandwidth, long-distance wireless networks got a boost last week as the U.S. Federal Communications Commission voted to let wireless devices using ultra-wideband radio technology be developed and sold in the U.S.
Ultra-wideband proponents say the technology promises, eventually, a spatial capacity (bit/sec/square metre) 1,000 times greater than 802.11b and has the potential to support many more users – at much higher speeds and lower costs – than current wireless LAN systems.
LANs based on 802.11b have a maximum data rate of 11Mbps, dropping to about 1Mbps at a distance of about 300 feet. Some ultra-wideband developers have claimed peak speeds, with current silicon, of 50Mbps over 30 feet. The actual distance and data rate will depend on variables such as signal power and antenna design.
The unanimous vote represented what commissioners called a “conservative” response to the opportunities, and the controversy, sparked by ultra-wideband.
But the vote is unlikely to defuse the battle. Groups as diverse as the Air Transport Association of America, Global Locate, Nortel Networks Corp., Nokia Corp., Qualcomm Inc., and until recently the U.S. Department of Defense, lobbied against the move to broaden the use of ultra-wideband. They charge that ultra-wideband will interfere with Global Positioning System frequencies as well as other public safety and air safety wireless networks, cellular PCS systems and some satellite services. Both sides say their positions are supported by test results in the past year.
“The FCC said ‘let’s assume [ultra-wideband] might cause interference; now let’s put these products in a frequency range where they won’t interfere [with existing spectrum users],'” says Al Haase, CEO of Skycross, a Melbourne, Fla., antenna builder that has adopted ultra-wideband principles to design a new generation of high-performance products. “Now ultra-wideband should be able to move forward into actual products without the lawsuits and other obstacles that might have appeared if it was operating in lower frequencies.”
The vote pledged the FCC to review this set of standards within six to 12 months, and to act quickly on interference complaints.
The change to the FCC rules means that ultra-wideband devices will be restricted to one part of the spectrum, well away from the frequencies used by other technologies.
There are also restrictions on how much electronic “noise” the devices can create in the lower frequencies.
Ultra-wideband uses short, low-frequency, very fast pulses that are spread over a range of radio frequencies. By contrast, radios in existing wireless LANs create a continuous wave along a narrow frequency.
The technology is in use by the military and intelligence agencies, and some civilian agencies, in the form of highly secure communications and ground- or building-penetrating radar and imaging systems.
Advocates were jubilant. Staff at XtremeSpectrum, a Vienna, Va., company creating ultra-wideband chips, broke open a case of champagne after the vote. Vice-President of Marketing Chris Fisher says the company will move forward on building chips for consumer electronics manufacturers.
Among the best-known ultra-wideband vendors are Aether Wire and Location, Multi Spectral Solutions, Pulse-Link, Time Domain and Xtreme Spectrum. Intel has a laboratory focused on ultra-wideband research. The Ultra Wideband Working Group, an advocacy organization, lists 150 members, including Compaq, DaimlerChrysler, Intersil, Lockheed Martin and Motorola.
