White-space spectrum debate rages

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.

[darkridedp]

Microsoft, defective. Let me put on my big surprise hat

Leave it to Microsoft of make yet another first attempt at something
so important by supplying a defective product. At least it's
consistent.

[charlesfelts]

White-Space Spectrum

You've over-simplified the situation to the point where it's very confusing.

Very High Frequency (VHF) analog TV channels 2 through 13 are supposed to go dark by March 1, 2009.

This is not a continuous chunk of spectrum. Channels 2 through 6 occupy most of the spectrum between 54 and 88 MHz, but there is a larger "white-space" between Channels 4 & 5 that is used for paging. The Frequency Modulation (FM) radio band occupies the spectrum between 88-108 MHz. General Aviation uses the spectrum between 108-136 MHz. Weather satellites use 136-138 MHz. Then, there's a plethora of police, fire, marine, taxicab, railroad, amateur, etc., users up to where Ultra High Frequency (UHF) TV spectrum starts.

UHF Analog TV Channels 14 through 69 occupy the spectrum 470-800 MHz. UHF Analog TV is supposed to go dark by March 1, 2009, also. UHF Digital TV Channels will continue to use the spectrum up to 700 MHz.

It's the guard bands between individual UHF Digital TV Channels that is being sought after by other potential users. I agree that the transition between Analog & Digital TV should be allowed to complete before allowing possibly interfering services to utilize the guard bands. Then, these additional services should be permitted only if it is determined that they can do so without interfering with the Digital TV signals