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Sound Advice: Into the Deep White Spaces

Complications arise over the expansion of wireless devices into the analog spectrum. 5/01/2008 8:00 AM Eastern

Sound Advice: Into the Deep White Spaces

May 1, 2008 12:00 PM, By Dan Daley

Complications arise over the expansion of wireless devices into the analog spectrum.




White spaces, the frequency bands between analog television channels, and the channels they separate are up for grabs with the impending February 2009 digital broadcasting switch.

White spaces, the frequency bands between analog television channels, and the channels they separate are up for grabs with the impending February 2009 digital broadcasting switch.

While you're at InfoComm, you may hear a ubiquitous referencing of the term “white space.” It refers to neither art nor fashion, but it is shaping up to become the global-warming issue of the RF universe in the United States. A serious hot button between both manufacturers of wireless audio products and their users, white spaces are the frequency bands between analog television channels. When the United States switches over to digital broadcasting (DTV) in February of next year, those bands and the old analog channels they separate will have gone to the highest bidder amongst a group of huge media corporations who want to use them for a new generation of consumer wireless devices.

We now know who the winners are. On March 20, the Federal Communications Commission (FCC) announced that telecom giants Verizon Wireless and AT&T took home the big prizes. Verizon bid $9.6 billion for most of the licenses in the prime 700MHz radio spectrum. AT&T won most of the regional licenses with bids totaling $6.6 billion.

It's those same white spaces that professional wireless audio users — concerts, theater, and so on — have been using in a very ordered (well, mostly) manner for decades. But now, professional audio is watching the titans in Washington, D.C., play football with their bread and butter.

Consumer electronics manufacturers and service providers that have enormous political clout via trade groups such as the Consumer Electronics Association (CEA) had long eyed these not-so-wide-open spaces. But another pair of giants (the names are about as big as they get in the new-media business) — Google and Microsoft, who are rivals in many other aspects of Internet business — had combined to petition the FCC to make the “unused” white space available for wireless Internet access as well, and in an unregulated manner. Dell, HP, Intel, and other computer-oriented corporations are joining the two technology behemoths in the effort, now called the White Space Coalition. Proponents of white-space networking claim that it could be used to allow broadband Internet connections of up to 80Gbps or 10GBps.

While Google did bid on the spectrum, its top bid barely surpassed the $4.6-billion minimum. It was enough clout to give the online search king what it really wanted: making certain that spectrum owners can't block out Internet or telecom rivals.


Sound Advice: Into the Deep White Spaces

May 1, 2008 12:00 PM, By Dan Daley

Complications arise over the expansion of wireless devices into the analog spectrum.




UHF spectrum after Feb. 17, 2009

UHF spectrum after Feb. 17, 2009

But this doesn't solve the issue of how wireless devices will steer clear of each other in the newly purchased ether. So far, one device — made by Microsoft and tested by the regulatory agency — has failed, and furthermore, it reportedly caused interference with existing licensed frequencies in the process. A second device has been submitted to the FCC, and testing has begun. However, underscoring the increasingly political nature of this issue, those who oppose making the white spaces the wide-open spaces — such as the National Association of Broadcasters (NAB), sports leagues, and professional audio equipment manufacturers — have interpreted the results of that second device so far as failures. NAB spokesman Dennis Wharton reportedly said, “Completing a successful transition to digital television ought not to be jeopardized by introducing risky technology that has proven to be unworkable.”

On the other hand, members of the White Space Coalition have claimed that the results of both tests weren't valid because the devices weren't functioning properly and that the NAB and others opposing the broadened use of the white space have exaggerated the preliminary failures.

“We're up against big business — very big business,” says Mark Brunner, senior director of brand management at Shure. The microphone manufacturer has spent much of the last two years intensively lobbying and educating members of Congress, as well as filing briefs with the FCC — the agency that will oversee the auction of the white spaces — in an effort to create some order in a post-digital broadcasting environment. Shure and other opponents of consumer electronics (CE) use of the white space have provided Congress and the FCC with test results, graphic demonstrations of CE device interference, as well as technical alternatives. These include spectrum-sensing technology and listen-before-talk protocols that can act as frequency traffic cops. Shure is also advising a working group from international standards body the Institute of Electrical and Electronics Engineers (IEEE) on amendments to the 802.22 wireless standard that could address the issue.

The problem is that we're living in an increasingly wireless world. As wireless CE devices such as cell phones and PDAs do more, they will get used more. This civilian use of wireless is encroaching on its professional audio applications in many areas — not least of which is installed systems, which themselves are using more and more wireless elements. The installed professional audio applications that have long used these frequency bands are going to have a tough time finding reliable bandwidth with which to use their increasingly necessary and prolific wireless audio systems. Imagine a typical Thursday night on the Las Vegas Strip: 30 hotels each with one or two multi-million-dollar theatrical productions running during primetime. More than 200 channels of wireless in operation. And at a key moment in any of the shows, a toxic burst creates a deafening noise glob throughout the installed sound system — or perhaps worse, produces the deafening silence of a primetime dropout. Imagine an argument on a cell phone breaking into the closing dance number.

The implications are significant for sectors that use ranged professional audio — not the least of which is the installed/integrated systems sector, the core constituencies of InfoComm and CEDIA (particularly InfoComm, with its emphasis on commercial installations). “InfoComm believes that professional audio productions face significant interference risk from the introduction of unlicensed devices in television broadcast bands unless FCC rules are developed that fully protect wireless microphone systems,” says Betsy Jaffe, director of government relations for InfoComm, in an email. “Wireless microphones should be protected from potential interference, as they are critical to effective and reliable communication.”

But it's a sensitive proposition, too. While entertainment entities such as broadcasters and theatrical organizations are raising the loudest opposition, the clients of systems designers and integrators easily fall into both camps: They'll want the wireless audio systems in the corporate theaters and boardrooms to be reliable, but they're also going to want their Blackberries and iPhones not only to work in that same environment but also to network in it.

Uncertainty seems to be all that's certain. Bob Green, director of Audio-Technica's global product strategy, wireless, says that the FCC's failure to precisely define the nature of the unlicensed devices that will use the newly available spectrum, how much of it they'll use, and what constitutes currently authorized wireless devices is clouding reality. “We'd like to see a test period in place after the analog signals are shut off,” he says. “As it stands, no one will know what's really going to happen until that day.”

Systems designers and integrators should watch how this situation plays out over the next few months. What we can hope for is that science prevails over commerce. Once you get the science nailed down, the commercial end of the equation can usually find a way to accommodate it.


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