Thursday, July 24, 2008

Searching For The Internet

WaPo has an interesting story about the quest to use the unlicensed airwaves between television channels, known as white spaces, that could provide a new form of mobile broadband Internet service.

Apparently many of the world's largest technology companies --Google, Microsoft, HP, Dell, Phillips -- are racing to figure out how to do it and not interfere with signals for Seinfeld reruns and other programming.

A lot of the testing to persuade the FCC to approve the technology is going on right in our backyard:

First out of the gate was a team from Motorola. On a recent steamy day in the middle of Patapsco Valley State Park about 10 miles west of Baltimore, Dave Gurney, an engineer for the company, set up shop in a parking lot surrounded by dense forest.

A large black box the size of a suitcase hooked up to a laptop sat near the base of a tree-covered hill. An antenna perched on a tripod rested a few feet away. A group of engineers stared intently at the contraption, as if it were about to spring to life.

"It's done!" Gurney said. He held his breath as the men leaned in further and quickly jotted down a cryptic list of numbers. Then he ran the test again.

...For more than a year, the agency has been testing prototypes with mixed results. An early prototype built by Microsoft failed to operate in the FCC's lab. Microsoft later determined the device was broken.

The FCC is now testing other prototypes built by Philips and Motorola as well as Silicon Valley start-up Adaptrum and Singapore-based Institute for Infocomm Research. The Motorola device connects to a database of TV stations operating within 200 kilometers and scans the airwaves nearly every second for other signals that may pop up unexpectedly, such as a wireless microphone.

If the device senses that it is within or close to a TV station's coverage area, it is supposed to avoid that station's frequency. It then ranks empty frequencies by their proximity to existing signals. If a new signal suddenly appears, the white-space device should automatically switch to another open channel.

Gurney ran the scan twice and recorded the results. He then covered the machine in bubble wrap, rolled it across the parking lot and ran the test again. Signal strengths can change by location, depending on how many trees, hills and people are nearby.

"We're testing multiple times to make sure the results are consistent," he said.

But the results can be hard to decipher. At the first location, Motorola's device indicated that channel 51, for example, was open and available. At the second location, the device picked up a weak signal on the channel, suggesting that it was already in use.

Motorola's engineers say that means the signal changed slightly between locations, and the device would be able to avoid that channel as soon as it was detected. But Bruce Franca, vice president of policy and technology for the Association for Maximum Service Television, a broadcasting industry group, is skeptical.

"The results of every single test were different," he said. "The device failed to recognize that certain channels are actually being occupied by TV signals. . . . Clearly this is not ready for prime time."

A prototype built by Adaptrum also got its turn in the hot seat -- literally. The sun was so bright in the parking lot that Haiyun Tang, chief technology officer of Adaptrum, shaded his device -- a jumble of wires and computer chips -- with an umbrella to protect it from the heat.

"Don't want to take any chances," he said.

Tang has traveled to Washington at least once a month since December to oversee the FCC's testing of Adaptrum's device. He is eager for the field tests to be concluded, he said, so the agency can use the data collected to write rules governing how white space products can be built. Because Adaptrum is a small start-up, Tang's ability to raise venture capital funding hinges on the FCC's decision, which is expected by summer's end.

Shure, which makes microphones and other audio equipment used in Broadway shows and sports games, argues the tests have not proven that the prototypes can consistently detect TV signals, let alone wireless microphones that hop on frequencies without notice.

The FCC plans to test the white-space devices at an entertainment venue in the next few months. The National Football League has offered the Baltimore Ravens' stadium or the Washington Redskins' park as possible venues. And the Recording Academy, which puts on the Grammy Awards, has offered up the Lollapalooza music festival in Chicago next month for testing.

"That's where the rubber will meet the road," said Mark Brunner, senior director of brand management at Shure.

FCC engineers said the tests were not intended to give passing or failing grades to the devices but simply to determine whether the prototypes are capable of sensing occupied signals. White-space proponents say they recognize the technology has a long way to go before it can be offered to consumers.

"The FCC is looking for evidence that using white spaces can be done -- any consumer device will have to go through a rigorous testing process as well," said Ben Scott of Free Press, a consumer advocate group. "Our goal is to take advantage of the available airwaves to offer much-needed broadband service."

Although the companies are working toward the same goal, the FCC's tests have brought out the competitive spirit between the engineers. Motorola's device is the only one with built-in access to geolocation data, while the Philips device can instantly sense a wireless microphone signal. Adaptrum's device has performed well in the tests, but it takes over an hour to scan the airwaves.

"Ours can do it in under six seconds!" Vic Tyagi, a member of Motorola's team, said with a smile. "Beat that."

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