The Quiet Zone

Sat Feb 21 09:01:26 CST 2004

Wired Magazine
Issue 12.02 - February 2004

The Quiet Zone

Cell phones, pagers, Wi-Fi, Bluetooth - the wireless revolution is 
everywhere. Except here.

By John Geirland

I'm 1 mile east of command central in the Quiet Zone, sitting in a Dodge 
pickup with Wesley Sizemore, Keeper of the Quiet. In a world saturated 
with radio waves, the Quiet Zone is a haven and an anomaly. A unique 
combination of geography and legislation has rendered its 13,000 square 
miles nearly free of electromagnetic pollution. Sizemore's job is to 
keep it that way. On this freezing afternoon, he's showing me the scene 
of his most storied success: a double-wide modular home amid brown grass 
and patches of snow in Pocahontas County, West Virginia (population 8,996).

One morning several years ago, Sizemore got a call. Broadband 
interference - noise, in common parlance - was wreaking havoc with the 
sensitive equipment at command central. After loading up his truck with 
a receiver, amp, spectrum analyzer, and directional antenna, he 
thundered into the countryside. Every quarter mile or so, he stopped, 
whipped out the antenna, and scanned the electromagnetic spectrum for 
spikes of activity. He methodically triangulated his way to this spot, 
where an elderly couple live with a nasty old dog penned in back. The 
couple had given the mutt a heating pad to lie on, but the pad had 
become worn; cracks in the wiring were causing tiny electric arcs to 
leap across the gaps. "Not enough electricity to shock the dog," 
Sizemore explains, but enough to produce a radio-frequency signal. He 
promptly disposed of the heating pad and bought the couple a new one. 
Just one more small step in humankind's exploration of the cosmos.

The Quiet Zone is a generous margin of mountainous terrain and rustic 
communities surrounding the Robert C. Byrd Green Bank Telescope, a 
485-foot, 17 million-pound structure that emerges improbably from this 
remote valley. Astronomers here observe the universe by studying faint 
radio waves emitted by stars, evaporating comets, and distant galaxies. 
These signals inhabit many areas of the electromagnetic spectrum - often 
the same areas prized by broadcasters, cellular providers, and other 
communications companies.

The subjects of radio astronomy are astronomically large, but the 
signals they produce are astronomically weak by the time they reach 
Earth. These emissions are measured in Janskys, named for the father of 
radio astronomy, Karl Jansky. A Jansky is based on 
0.00000000000000000000000001 watts - and that's a big signal at Green 
Bank. Even a musical greeting card playing at the base of the telescope 
could produce anomalous spikes in the data of an unlucky astronomer 
trying to study stellar gases. If the interference is strong enough, the 
telescope's ultrasensitive first amplifier - cooled by liquid helium to 
minimize internal noise - shuts down.

Sizemore, 49, has safeguarded the telescope and its mission since 1983. 
One minute he's running signal propagation models, the next he's 
sledgehammering the base of a power-line pole to rejigger its 
insulation, and then he's alerting the site director about an unexpected 
incursion: North American flying squirrels tagged with telemetry 
transmitters, a project of the US Fish & Wildlife Service.

In the past few years, however, Sizemore's job has become overwhelming. 
The wireless revolution has swept the country beyond the Zone. First 
pagers and cell phones, then satellite radio, souped-up walkie-talkies, 
Wi-Fi, and Bluetooth - one after another, these technologies have 
cranked up the surrounding cacophony. There are even sources of 
radio-frequency interference raining from the sky: Transmissions from a 
Russian Glonass satellite recently derailed efforts to study a faraway 
cluster of galaxies.

Sizemore's efforts to shield Green Bank's radio waves from the 
encroachment of civilization may make him seem a quaint relic of the 
past. Actually, he's a harbinger of the future: The problems that keep 
him awake at night are increasingly everyone else's problems, too.

While electromagnetic spectrum is a finite resource, the number and 
variety of gadgets emitting electromagnetic energy continue to grow. As 
the airwaves become more crowded, signals from devices operating in 
neighboring frequencies spill into one another's bands. When spectrum 
allocation frays at the edges, devices go haywire: Garage doors open and 
close by themselves, phone conversations blare over baby monitors. The 
stakes also can be frighteningly high, as when emergency workers can't 
coordinate a disaster response effort. Some observers fear that 
interference is becoming so severe that soon there won't be enough 
spectrum to go around.

Sizemore has been feeling that way for a long time. He has been tracking 
down and stifling stray signals for more than two decades; engineers and 
regulators are just beginning to explore ways of operating in a 
spectrum-saturated environment. "In terms of the RFI issue," says Green 
Bank site director Philip Jewell, "we're the canary in the coal mine."

The astronomers who selected Green Bank as the site for the telescope in 
the mid-1950s chose carefully. The surrounding Allegheny Mountains 
provided a natural shield against radio and television broadcasts. 
Flanked by national forests teeming with black bears and wild turkeys, 
the area would remain undeveloped in perpetuity. And for all its 
physical isolation, it was only a day's drive from many East Coast 
universities. Even back in the '50s, though, farsighted scientists 
feared that radio-frequency emitters would eventually creep into the 
area. More aggressive protection would be necessary.

Thus, in 1958 the FCC set aside a rectangular-shaped territory the size 
of Massachusetts and Connecticut combined and called it the National 
Radio Quiet Zone, to be administrated by the National Radio Astronomy 
Observatory, a government-funded research facility in Charlottesville, 
Virginia. The NRAO later built other radio telescopes - in Socorro, New 
Mexico (the setting for the film Contact with Jodie Foster), and Tucson, 
Arizona - but it never again had the clout to impose quiet around them. 
Today, Green Bank is radio astronomy's crown jewel. Over the years, the 
telescope has played a key role in understanding the behavior of 
pulsars, searching for extraterrestrial life, and probing the halo of 
hydrogen that surrounds the Milky Way galaxy. It's one of the few 
facilities on the planet where radio astronomers can make observations 
at most points along the electromagnetic spectrum.

All major transmitters in the Zone are required to coordinate their 
operations with the national observatory. Radio stations point their 
antennas away and operate at reduced power. Cell phone base stations are 
few and far between, and entirely absent deep in the Zone. Even 
incidental electromagnetic emitters are regulated: Power lines must be 
buried 4 feet belowground. The wireless LAN card in your laptop? Forget 
about it.

"Your cell phone and pager won't work here," Sizemore warned me before I 
came out for a visit. He was right. As I negotiate the snowy switchbacks 
on Route 250 West, my cell phone passes out of service while the FM dial 
gradually becomes depopulated. By the time I reach the tiny burg of 
Green Bank, all I can get is a static-shrouded episode of A Prairie Home 
Companion from a radio station outside the Zone.

The facility itself looks like any high tech office building, except for 
the full-scale replica of the antenna Jansky used in 1932 to discover 
"mysterious radio waves" emanating from the Milky Way - a natural 
phenomenon that, for a time, he mistook for communications from an alien 
civilization.

The next morning, I meet Sizemore for breakfast in the dining hall. He 
shows up in a black leather jacket and an earth-toned, Navajo-print 
flannel shirt. His beard is a thicket of graying bristles. Sizemore grew 
up in the mountain hamlet of Trout, West Virginia. He spent six years in 
the Navy, during which he was stationed in the Bahamas and the 
Mediterranean before returning to West Virginia to attend Bluefield 
State College. Then he was off to the Cleveland Institute of 
Electronics, where he earned an associate degree in electrical 
engineering. He's an Appalachian-high tech hybrid who makes his own wine 
and listens to NPR.

He's also a verbal snowplow when he gets worked up about the Quiet Zone. 
Once he latches onto a subject like "tropo-scatter" or "free space 
loss," he's unstoppable. "I take the maintaining of the Quiet Zone very 
personal," he explains in a West Virginia lilt. "It's my way of making a 
contribution to the body of mankind's knowledge."

The quiet lets astronomers measure electromagnetic waves thrown off by 
space-borne molecules when they become heated or collide. Each type of 
molecule emits energy in a unique frequency band; hydrogen, the most 
abundant molecule in the universe, is in the 1,400 to 1,427-MHz range. 
This band and a few others have been set aside by international treaty 
exclusively for radio astronomy. In practice, spillage from neighboring 
bands can cause interference even in these tiny slivers of spectrum.

Although just about any electronic or electromechanical device can blind 
Green Bank's telescope, the biggest culprit in the first category is the 
observatory itself. After all, it's a high tech operation crammed with 
sophisticated electronics and PCs. Green Bank director Jewell believes 
that some of the steps taken to mitigate interference at the facility 
may someday be adopted in the wider world, such as innovative circuit 
board designs and extensive shielding. The cafeteria's microwave oven is 
kept in a shielded cage. Large chambers designed to absorb radio waves - 
including a 5,000-square-foot conference room - have been built to make 
sure that, as Sizemore tells it, "radiation generated in the building 
stays in the building." Outside, spark plugs are notorious 
radio-frequency emitters, so Green Bank maintains a fleet of 
diesel-powered, electronics-free '69 Checker cabs and '70s Dodge trucks.

Thousands of tourists visit Green Bank each year, many of them stuffing 
their day packs with cell phones, two-way radios, and similar wireless 
gadgetry. The good news is that these devices operate at low power 
levels. The bad news is that they're mobile. The FCC doesn't control 
unlicensed transmitters, but West Virginia's Radio Astronomy Zoning Act 
prohibits any RFI-generating device - licensed or not - within 2 miles 
of the telescope.

Sizemore is more anxious about pervasive emitters: cellular telephones, 
two-way pagers, wireless email. Under FCC rules known as geographic area 
licensing, service providers can erect transmitters anywhere in a 
designated region without notifying the commission of the exact 
location. The policy worries Sizemore. "We don't know where the final 
transmitter sites will be," he says, which makes it difficult to assess 
the impact of a new transmitter on the telescope's operations ahead of 
time.

Meanwhile, there are more immediate challenges. Sizemore wants to show 
me a transmitter that poses a direct danger to the telescope, a kind of 
electromagnetic sword of Damocles. "Dress warmly," he warns.

The next morning, we're standing on the icy patio of the Sunrise 
Backcountry Hut, a remote cabin on top of a mountain a couple miles from 
the Snowshoe Mountain ski resort. Sizemore was right about bundling up. 
It's 14 degrees, and snow flurries whirl overhead.

Snowshoe wants to install a transmitter to relay the cabin's 
smoke-detector alarm to headquarters. But the cabin is only 7.5 miles 
from the telescope, with no mountains in between. If the alarm went off 
and the transmitter relayed its signal, the result, Sizemore says, would 
be "catastrophic."

Before the resort can install the transmitter, it must obtain a waiver 
from Green Bank. And when it comes to waivers, Sizemore's standard line 
is "If you're going to make a buck with it, don't ask!" But this case is 
different. Public safety trumps research.

The trick is to configure the system so it won't blow an amp at Green 
Bank the moment a hapless lodger attempts to cook blackened salmon. It 
may be possible to equip the emergency transmitter with a directional 
antenna aimed at a 90-degree angle away from the telescope toward a 
Verizon wireless base station in Warm Springs Mountain, Virginia, about 
40 miles south. Then the base station would redirect the signal back to 
Snowshoe. Sizemore and Nathan Sharp, a lanky Green Bank technician, test 
the idea with their own equipment, which includes an antenna that looks 
like a high tech coatrack. "Slow and easy. Keep going to the right," he 
tells Sharp, who is gripping the antenna. "That's a nice strong signal 
there."

While Sizemore and Sharp fiddle with the antenna, I catch a bumpy 
snowmobile ride down the mountain to talk to Jim Haas, VP of resort 
services at Snowshoe. Haas, a pale, beefy man with a wispy soul patch, 
wears a blue jacket and matching Snowshoe cap.

The smoke detector is just one detail in a much larger system that 
Snowshoe has had to adapt to Quiet Zone priorities, Haas tells me. "It 
has made our communications more difficult and cost us more money," he 
says without rancor. The resort has staff operating on both sides of the 
mountain, and normal practice would be to install a repeater at the peak 
to boost signals to employees' handsets. But that would fry the 
telescope, so he's had to install hardwired components at double the cost.

Still, Haas isn't complaining. "Wesley has worked as hard as anyone to 
find ways for us to operate," he says. Haas has been an employee at 
Snowshoe for more than 25 years - he knows the rules of the Quiet Zone. 
Skiers are a different matter. "People are bringing Motorola Talkabouts 
on the mountain," he says, and there's little Sizemore can do about that.

By the time I get back up to the Sunrise Lodge, Sizemore is showing the 
Snowshoe staff how the directional antenna can be placed under the metal 
roofing, further shielding the telescope from the transmitter's signal. 
The beauty of the scheme is in its economical use of power and spectrum. 
A typical antenna would radiate 48 watts of power in all directions. The 
directional antenna concentrates only 3 watts in one direction - toward 
the Verizon tower - accomplishing the same goal far more efficiently.

Sizemore's solution is typical of his stingy approach toward spectrum. 
He uses an optical analogy to make his point. "Why do we have 
streetlights that shine up into the night sky?" he asks. "We're 
illuminating the bellies of airplanes for no reason. So why would you 
have an antenna radiating in all directions when you want to communicate 
in one direction?"

As I gaze out over the snowy Allegheny Mountains, I imagine the area 
surrounding the Quiet Zone as a huge mosaic of RF emitters. Sizemore's 
job is to fit all the pieces into a harmonious whole - and to do so 
constantly, in an ever changing landscape. This concept, as it happens, 
may be the ultimate solution to the interference problem everywhere.

There's no question that use of the electromagnetic spectrum is sharply 
increasing. In 1994, the FCC projected that by 2000 there would be 54 
million users of mobile wireless services in the US; the actual number 
reached 110 million. In spite of industry woes, the number of cellular 
base stations worldwide is expected to climb from 1.3 million in 2003 to 
1.6 million by 2006, serving 1.8 billion wireless users. Meanwhile, 
short-range and satellite transmissions are multiplying.

The parts of the spectrum set aside for unlicensed devices - the 
900-MHz, 5.7-GHz, and 2.4-GHz bands - are getting especially noisy. 
Recent technologies like Bluetooth and Wi-Fi are choking these 
frequencies. To make matters worse, the popular 2.4-GHz band shares 
space with medical, scientific, and industrial devices, like the huge 
microwave ovens used to dry plywood.

The soft signs of a growing interference problem are everywhere. 
Cordless phones in the 2.4-GHz band interfere with Wi-Fi. Until 
recently, some radar detectors (popular among truckers for spotting 
police) disrupted terminals used to authorize credit cards at gas 
stations or pipe Muzak into burger joints.

Some RFI effects are as comical as they are unexpected. Errant radio 
waves caused mischief on the Spider-Man movie set when emissions from a 
high-powered walkie-talkie tweaked a timing processor on a generator, 
killing the lights in the middle of a tear-jerking scene.

Other incidents have been more serious. Six years ago, broadcasts from 
Dallas-based WFAA, the country's first digital TV station, interfered 
with wireless heart monitors at Baylor University Medical Center. (The 
hospital spent $200,000 on new machines.) And last May, a baby monitor 
hindered air-traffic control communications as pilots approached 
London's Luton Airport.

Some experts fear this is the leading edge of a spectrum meltdown, but 
others have high hopes for new technology. Dennis Eaton, chair of the 
Wi-Fi Alliance, is undaunted by reports of Bluetooth devices hopping all 
over Wi-Fi connections or interference between overlapping hot spots 
operating on the same frequency. "I put my faith in the engineers who 
are designing new equipment," he says.

Eaton may be right. Already, phased-array antennas can make more 
efficient use of existing spectrum. An approach known as cognitive radio 
might have an even bigger impact. Unlike your local Top 40 radio 
station, which transmits 24/7, unlicensed wireless devices tend to use 
the airwaves intermittently. At any particular moment, the spectrum is 
rife with unoccupied frequencies, or "white holes." Cognitive radio 
hunts out these holes and makes temporary use of them. If this 
technology catches on, every Wi-Fi base station or cordless phone could 
contain its own little Wesley Sizemore.

Indeed, radios are getting smarter. In January 2003, the US Department 
of Defense reached an agreement with technology companies requiring 
manufacturers to enable Wi-Fi devices to detect activity in frequencies 
used by military radar and, if they sense it, to avoid those parts of 
the spectrum. FCC rule changes are enabling manufacturers to produce 
Bluetooth devices that sniff out Wi-Fi signals and dodge them by 
broadcasting in other frequencies.

Such strategies may ease interference problems in the larger world, but 
the Quiet Zone is a different matter. Sizemore fears that cognitive 
radio would allow people to use spectrum bands that previously had been 
quiet - creating another source of noise rather than a solution. The 
more the FCC loosens the regulatory reins - allowing cognitive radio, 
instituting geographic area licensing, opening more spectrum to 
unlicensed users - the more difficult it becomes to maintain the quiet 
in the Zone. Even if the outside world does evolve into a laissez-faire 
commons, as some observers advocate, the Quiet Zone must remain an 
embattled bastion of command and control.

Sizemore gives me a final spin around the observatory grounds. He looks 
tired. He drives past one of the smaller radio telescopes, used in 1961 
by astronomer Frank Drake, who created the famous equation for 
estimating the number of intelligent civilizations in the universe. 
Sizemore is playing a high-stakes endgame. He's determined to protect 
this last clear portal to the cosmos. "The Quiet Zone is like a 
wilderness," he says softly. "Once it's gone, it's gone for good."