White space approval: Is it a matter of when?

The FCC will begin field testing white space devices today to see whether the devices that access unused television airwaves, called "white spaces" will interfere with television broadcasts. That means the stakes are higher for everyone on both sides of what has become a contentious debate full of paranoia and fear.

Nearly everyone has weighed in on the debate. Companies such as Google and Microsoft want to use this unused spectrum to develop new mobile communications devices, but the initiative has raised the ire of the National Association of Broadcasters, which argues that "white space" devices may interfere with existing television broadcasts. Meanwhile, wireless carriers and the CTIA have advocated auctioning off the white space spectrum as has the NAB. Entertainers, sports leagues and hospitals have all voiced their concerns about potential interference with wireless microphones and hospital devices.

For its part, the Wireless Innovation Alliance, made up of a number of different companies advocating white-space services (Skype its its most recent member), says the FCC's approval of such devices is not a matter of if, but just when. "It's not a question of science. It is a question of politics," said spokesman Jake Ward in an interview. He expects the FCC to move forward with its final order immediately after this round of testing.

Of course, talk to the NAB and you get a whole different story. It remains highly skeptical that these field tests will prove themselves given the failures of prototypes in the lab. The first round of prototypes from Microsoft and Philips did indeed fail in lab test, but a second set of devices have done well enough on the lab that now the FCC is moving to field tests.

But the NAB isn't totally against white space spectrum per say. It's just against the unlicensed part. "We would like to see a fixed license system that would allow broadcasters, if there are interference issues that come up, to go to the FCC and figure out where interference is coming from," said spokesman Kristopher Jones. "In unlicensed world, we don't know where it would be coming from. The problem with unleashing these devices is that once they are out on the market, there's no pulling them back."

Can this spectrum actually be offered on a licensed basis? Steve Sharkey, senior director of regulatory and spectrum policy with Motorola, also an unlicensed white-space advocate, says no. "White space encompasses about 300 megahertz of television spectrum (after the DTV transition), but at many locations there are only portions available as you move from place to place. It's much more difficult to have usable spectrum. When you have to share with incumbent providers, it has to be an unlicensed approach," he said.

And there is strong evidence white-space devices can operate on an unlicensed basis, Sharkey says. All of the tests the FCC has done to date incorporated sensing technology--a technology similar to one used for cognitive radio communications. But Sharkey says more technologies can be incorporated to make sure interference doesn't happen. Motorola advocates geolocation technology that maps the location of the device and compares its location to that of TV stations in the area. Motorola's devices will be among the group of devices that will be tested in the field, and some will include geolocation. Sharkey says other technologies such as beacons can also add another layer of assurance.

Will all of this allay the concerns of the naysayers? Even if these prototypes, which are big boxes at this point, don't come out passing with flying colors, you can bet the FCC will go back to the drawing board because Chairman Kevin Martin and other commissioners want to see more broadband competition in the market. White space advocates say it's a matter of when and not if, but that when could turn out to be a long time if all doesn't go well during the next several weeks of testing. --Lynnette