Radio Freakquency

  • Not long ago, I walked out of the shower in my New York City apartment and came face to face with a man. Given that I'm married, that's not so unusual. But this man was hanging from a lamppost outside my window. I shrieked and ran out of the room. When I returned, clothed, he was gone, but I didn't like what he'd left behind: an odd, toaster oven-size box with a 2-ft. antenna dangling below it.

    What was this contraption? I puzzled over its presence for months, asking anyone willing to look up. I finally got my answer from a city worker. The box was a small relay station designed to send signals to and from wireless modems. It had landed outside my bedroom courtesy of Metricom's Ricochet network. The California-based company is blanketing more than a dozen U.S. cities with pole-top radio transceivers strategically positioned every five to 10 blocks so we can send e-mail, visit websites and otherwise reach out and touch the Internet--wirelessly--anytime, anyplace.

    Hey, I don't even own a laptop. But that doesn't stop me from wondering what kind of radio waves this wireless wonder emits. After dozens of phone calls to government regulators and engineers, I discovered that the boxes give off what's called effective isotropic radiated power, some of it traveling in the same frequency range that microwave ovens operate. Depending on a number of complex technical considerations, the FCC allows Metricom's transceivers to emit anywhere from 1 to 6 watts of EIRP. Radiated power--words that make me want to duck for cover--drops off precipitously with distance, so that at 20 ft. (about how far my bed is from the lamppost), 6 watts is negligible. "It falls way below a level that would put anyone at risk," says Julius Knapp, an engineer at the FCC's office of engineering and technology.

    For most folks, that's reassurance enough. Not for me. After all, I never asked to live in a wireless world. While Metricom says its emissions fall below the FCC guidelines, no one knows the long-term effects of even the lowest levels of radiated power generated 24/7. Metricom's website states that "reports are inconclusive that wireless radio frequencies pose significant health risks to users." Moreover, Metricom's radios operate in two license-free frequency bands. That means, according to Howard Epstein, head of Consolidated Spectrum Services in Atkinson, N.H., that once the boxes are up, "neither the government nor the company is required to go to street corners and audit the invisible electromagnetic field they're emitting."

    What can you do if a strange box appears outside your bedroom window? You can try calling the company to ask if it will move the thing. (That's what Metricom, in the interest of fostering good community relations, finally did for me.) Alternatively, there are a number of products designed to keep out UV light that can also block radio waves. Radio frequencies travel easily through glass, but not through bricks or metal. 3M sells Neutral Series Scotchtint, a professionally applied coating that covers windows with a nearly transparent layer of metal. MSC Specialty Films offers a similar product. If you're desperate, you can always drape your window with aluminum foil (which I actually did one night). Or, you can just relax and enjoy the connectivity.

    Related:
    OSHA'S website on Radiofrequency/Microwave Radiation

    Microwave News

    The EMR Network

    Metricom

    Questions for Janice? E-mail her at jmhtime@aol.com