White-space spectrum debate rages
By Marguerite Reardon
News.com
http://news.com.com/White-space+spectrum+debate+rages/2100-1034_3-6202753.html
Story last modified Thu Aug 16 09:02:29 PDT 2007
Technology companies are putting pressure on the Federal Communications
Commission to open up unused wireless spectrum between TV channels for use
with unlicensed devices, but the TV broadcasters say there are still too
many interference issues.
Most broadcast channels are separated by small swaths of spectrum, or
unused channels called white space, which limit interference from other
stations. Technology companies and consumer advocates believe the use of
this unlicensed spectrum could open up a wireless broadband pipe into the
home, providing a competitor to cable and DSL services.
Technology companies in particular say that using the spectrum between the
TV channels could unleash a wave of innovation. These companies, which
include Microsoft, Intel, Google, EarthLink and Dell, have joined forces.
Calling themselves the White Space Coalition, they've been lobbying the FCC
and Congress to open up this spectrum.
Not surprisingly, TV broadcasters oppose allowing any unlicensed device to
use white-space spectrum because, they argue, these devices would interfere
with television broadcasts, potentially harming the federally mandated
transition from analog to digital TV service.
"There are serious interference issues with unlicensed devices," said
Dennis Wharton, spokesman for the National Association of Broadcasters.
"Our suggestion to the FCC is, let's get through the analog transition to
digital TV before we suggest introducing unlicensed devices onto airwaves
that could cause disruption to millions of TV viewers."
Congress has mandated the airwaves in the 700MHz band be vacated in
February 2009, forcing analog TV broadcasters off those channels as part of
the long-anticipated switch to all-digital television. Current and would-be
wireless broadband operators are eager to get their hands on the spectrum
because of its inherent physical properties, which allow signals to travel
farther and more easily penetrate walls.
Countering Wharton's argument, the White Space Coalition says that it can
design devices that don't interfere. And it submitted prototypes to be
tested by the FCC earlier this spring.
Testing of these devices has recently been completed with mixed results. On
July 31, the FCC issued a report saying that a testing prototype developed
by Microsoft failed to detect digital TV signals in order to avoid them in
tests designed by the commission. But another device, made by Koninklijke
Philips Electronics, was able to detect broadcast signals, according to the
commission's report.
Microsoft is now saying that the results of the FCC test are invalid. In a
letter it filed this week with the FCC, Microsoft said the device the FCC
tested was defective. And another model of the same device worked
successfully in a demonstration it gave to the FCC last week, according to
the letter.
"We don't think anything the commission did in its testing in any way
diminishes the potentiality of white-space devices," said Ed Thomas, former
chief engineer at the FCC and now technology policy adviser and partner at
Harris Wiltshire & Grannis, the firm representing the White Space
Coalition. "We still believe that the white spaces could be used without
causing harm to broadcasters. And we want to work with the commission to
product the services of incumbent licensees."
What is white space and why should I care?
The FCC has had an open proceeding on the possibility of using this
spectrum since 2002, but it still hasn't taken any action. The FCC's office
of engineering and technology plans to hold an open meeting Thursday to
discuss testing options for new white-space devices.
White space spectrum, like the 700MHz spectrum that will be auctioned off
early next year, is considered perfect for wireless broadband use, because
it propagates over long distances and penetrates through obstacles.
Today, both the 700MHz and white-space frequencies are used to deliver
analog TV service. But when broadcasters transition to digital TV service
in 2009, the 700MHz spectrum, which includes broadcast channels 52 to 69,
will be auctioned off. And spectrum between channels 2 to 52 will
essentially lay fallow. Public policy experts see this transition to
digital as a perfect opportunity to make spectrum available for new players
who want to compete in the broadband market.
On their own, these slivers of wireless spectrum are not sufficient to
provide enough capacity for companies to build wireless broadband services
that truly compete against high-bandwidth services offered by the cable and
phone companies. But combined with other pieces of spectrum, like Wi-Fi,
this spectrum could provide enough capacity to deliver competitive services.
"The 700MHz spectrum is not enough to compete against a service like
Verizon's Fios," said Harold Feld, senior vice president of public-interest
nonprofit Media Access Project, in reference to Verizon Communications'
high-capacity network featuring fiber-optic connections to the home. "It's
only 62MHz of spectrum. So you're going to need a lot more. That's why it's
important to provide access to licensed as well as unlicensed spectrum."
The amount of spectrum that is available in white spaces varies from market
to market. In rural areas where fewer broadcasters are operating, it can
provide a substantial amount of capacity. But in dense urban areas, white
spaces offer far less capacity because more broadcasters are using the
spectrum. For this reason, white-space spectrum could be particularly
valuable for providing broadband access in rural areas, where large cable
companies and telephone companies have not built wired infrastructure.
But it also could be used in urban areas. Because white-space spectrum is
unlicensed and, therefore, free to anyone who wants to use it, it makes a
nice complement to citywide Wi-Fi networks. Wi-Fi operates in the higher
frequency bands of 2.4GHz and 5.0GHz. But because it's at a higher
frequency, it propagates over much shorter distances and has difficulty
penetrating walls and sometimes even foliage.
White-space spectrum in the analog channels, which operate between 54MHz
and 698MHz, provides an inexpensive way for service providers such as
EarthLink, which is building citywide Wi-Fi networks, to extend their reach
and improve in-home coverage.
And now that the FCC has rejected rules requiring winners of certain 700MHz
auction licenses to offer wholesale access to that spectrum, access to
white-space spectrum is even more important for prospective competitors of
the cable and phone companies.
"We didn't get the open access that we wanted on the 700MHz auction," Feld
said. "So it makes it that much more important that new providers can
access white-space spectrum."
But broadcasters say they don't think it's possible to solve the
interference issues. With roughly 15 percent to 20 percent of the
TV-viewing public still getting their TV service over the air, Wharton
said, the risk is still too high.
"If there was ironclad proof that no person in America would lose access to
over-the-air TV signals, then maybe we wouldn't have a problem with the
introduction of unlicensed portable devices," he said. "But engineering
studies and folks that we have talked to say the likelihood of developing a
product that wouldn't interfere with TV broadcasts in large markets is nil."
================================
George Antunes, Political Science Dept
University of Houston; Houston, TX 77204
Voice: 713-743-3923 Fax: 713-743-3927
antunes at uh dot edu
