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FCC mulls thin spectrum for wireless

Federal regulators are deciding whether to let private wireless companies operate in a very hard to manage patch of spectrum that accommodates only pencil-size radio waves.

Federal regulators are deciding whether to let private wireless companies, such as broadband providers or telephone companies, operate in a very hard to manage patch of spectrum that accommodates only pencil-size radio waves.

This "Upper Millimeter Wave band" is the only area of broadcast spectrum where the wavelengths that make up a wireless transmission are required to be that small. Usually, they can be more than a meter wide as they travel through the air.

Creating radio signals the size of laser beams is so difficult that this patch of spectrum has been all but unused, even by the military and other U.S. agencies, which have the exclusive rights to it. But if harnessed, the handful of companies now experimenting with the spectrum, between 71GHz and 95GHz, say it could deliver up to 12.5 gigabyte Internet access to homes or businesses as many as 12 miles away from an antenna.

"That's about 1,000 T1 lines," said Lou Slaughter, CEO, Loea Communications, which has been experimenting with the bandwidth.

The FCC this week began the process of trying to license the spectrum for commercial use, a process that could take years. FCC Commissioner Kathleen Q. Abernathy said that bandwidth in general has become scarcer and scarcer, forcing the FCC to begin exploring what were once even the most technically challenging bandwidths to use.

"There was certainly a time when...interests looked askance at...the 70-, 80- and 90GHz bands we examine today," she wrote.

The FCC said it would begin seeking comment on whether to create licenses for this spectrum or make it free to use. How much bandwidth in these areas should be used and whether it should be shared with government users are also part of the inquiry, the FCC said.

It will be a unique inquiry, FCC Commissioner Michael J. Copps wrote in comments released this week.

"We've been dealing with apples and oranges in comparing this spectrum to other bands," he wrote. "These bands are very different than most of our other bands, and we need to keep our minds and options open."

Sharpening ideas for the spectrum
One possible use of this spectrum would be to help find a new way to circumvent what is usually a laborious and expensive process to deliver broadband Internet service from an underground fiber-optic network into a home or office, according to the FCC.

Most broadband access is confined to large metropolitan areas, where service providers build fiber-optic networks that literally ring a city. That makes it easier to add new customers just by stringing a few hundred feet of wire from the fiber-optic ring to a home or office.

But to add a customer in rural areas means either extending the fiber-optic network, which can be very expensive to do, or stringing hundreds of miles of cable or wire, which can sometimes be impossible to do because of rough or remote terrain. As a result, broadband services have largely skipped rural areas.

Some service providers have begun exploring the use of fixed wireless networks to cover rural areas. Fixed wireless equipment showers high-speed bandwidth through the air, sometimes miles at a time.

The FCC began looking at this area of waves in July 2000 after a workshop on new uses of spectrum in the 90GHz range. In July 2001, Loea Communications let the FCC know about some of its experimental success with the technology.

The Hawaii-based company, according to a representative, put its equipment into a Maui resort hotel and began broadcasting a signal several miles away. The company said patrons at the hotel used the system for broadband access, video-on-demand services and teleconferencing.

Slaughter said the trials proved an important point: that the waves will stay densely packed and not spread out that much as they travel through the air.

In related news, the FCC recently approved the commercial use of ultrawideband, which provides a fast and secure way of sending wireless transmissions.