FCC lab keeps radio signals in check

FEDERAL WORKERS

April 21, 2006|By MELISSA HARRIS

If children could watch the tests conducted here, inside this bland, boxy building in Columbia surrounded by an unattractive chain-link fence, they would think the place was haunted. An engineer clicks on a small lamp and the picture on the nearby television set immediately contorts into abstract art. Another engineer flips on military radar, and the video being played on a nearby laptop freezes.

The magic wands in both cases are invisible signals that travel through the air and make BlackBerrys, radios, satellite TV, pagers, walkie-talkies, garage-door openers and a lot of other gadgets work. A small group of federal engineers in Columbia ensures that the waves powering these everyday devices do not interfere with each other and that the radiation emitting from them does not harm users.

The efforts of these approximately 30 Federal Communications Commission workers will become even more important during the next few years. Congress eventually will decide whether to stick to its plan to complete the switch to digital television in 2009 - rendering old sets still living on bunny ears useless - and turn over more of the crowded, public-owned spectrum to private companies.

The spectrum is like real estate. A broadcaster's spot on it, for instance, decides whether a TV station airs on Channel 11 or Channel 7, or a radio station is tuned at 88.7 or 101.9. Some spots on the spectrum are like living on Park Avenue, others are like living in the Sahara Desert. If devices do not stick to their assigned spots, radio communications can crackle, television pictures can turn to snow or, more dangerous, hospital equipment can stop and military radars can go blank.

"We ensure that these devices are safe and avoid interference," said Rashmi Doshi, chief of the FCC's lab on Oakland Mills Road next to Guilford Elementary. "But we also want to avoid undue burdens on companies. ... We want them to meet our rules, but not create a bottleneck."

Doshi's staff oversaw the certification of about 9,000 new devices last year. He said that if the FCC does not move quickly, a new, faster gadget could be invented by the time the agency finishes approving the sale.

When the FCC opened this facility inside a World War II-era Columbia farmhouse, the surrounding landscape was rural. Doshi said that the sky was so free of "electromagnetic chatter" - signals - that the staff did most of its testing outside. Today, much of the work is done inside a two-year-old anechoic chamber, a sealed, echoproof box housed inside the current lab, built in 1972 directly in front of the farmhouse.

This week, Steve Jones, a senior electrical engineer, tested what looked to be nothing more than a red, plastic box in the chamber. However, this device, ground-penetrating radar, can do some amazing things. As it is carried over land - either dragged or strapped to a vehicle - it sends a signal into the earth that can detect where potholes might emerge, where bridges might have flaws or even where criminals have buried bodies.

Because of FCC regulations, these devices do not work very well unless they travel at slow speeds. Companies want to be able to drive them faster, so that they do not impede traffic. However, for the radar to work at normal traveling speeds, it needs to emit its signal more frequently. Jones is trying to discover whether doing so would cause interference with other devices.

Doshi and his staff know that it is very difficult for nonengineers to understand their work. So to make the problems that they solve easier to understand, they tell the story of the small lamp.

The lamp's post is a baby monitor wrapped in a teddy bear. Sold in the late 1980s on commissaries at military air bases, the FCC approved the monitor, but the manufacturer made a severe error during production.

Soon after its release, "pilots would report that as the aircraft was coming in, instead of hearing the air traffic control tower, they'd hear babies crying," said Raymond LaForge, chief of the lab's auditing and compliance division. The monitor's signal even interfered with WBAL-TV in Baltimore.

Today, however, the FCC's research focuses on far more high-tech devices, such as Bluetooth earpieces, which wirelessly link up with cell phones.

One such cutting-edge technology is called smart networking. Andy Leimer and Richard Tseng, both electrical engineers, are testing one example of this. The government takes up about half - some would argue hoards - of the spectrum. Consumer groups and private companies are increasingly pressuring the government to share that space.

The way to do that is to build devices that use the spectrum when it is empty, and then move aside when the government needs it. Demonstrating one such device, Leimer has a wireless Internet site - called a hot spot - streaming video to a laptop in the lab. When Leimer turns on military radar sitting on a nearby table, the video stops streaming. If the hot spot were installed in a home or neighborhood, it would automatically move to a different frequency when the military device activated, without the video skipping a beat or the user noticing.

"It gets out of the way," said Bruce Romano, associate chief of the Office of Engineering and Technology. "It gives us the ability to share."

The writer can be reached at melissa.harris@baltsun.com or 410-715-2885. Back issues can be read at baltimoresun.com/federal.

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