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White Spaces: Now It’s GE

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Medical device manufacturers now fear using unused television channels (”white spaces”) to transmit data could interfere with older medical devices, reports C/Net.

As detailed in the Journal Biomedical Instrumentation & Technology a few years ago, wireless heart monitors, used at Baylor University Medical Center in Dallas a decade ago, went on the fritz. The trouble, it turned out, was interference from a nearby broadcast television station.

In an effort to mitigate the problem, the FCC cordoned off spectrum on channel 37 just for medical devices. Broadcasters were banned from Channel 37. So are the so-called “white space” devices that operate like miniture WiFi radios which are expected to have a maximum power of 1 watt (fixed) and 100 mW (mobile).

But the FCC also allowed hospitals to continue operating existing devices on other TV frequencies, with the understanding that they would be best served by moving to channel 37 eventually.

Now, hospital administrators are worried that patients using older devices, not using Channel 37, will receive harmful interference — and that the move to Channel 37 could cost them money.

Patients wear a small transmitter that allows doctors and nurses to check on the patient from anywhere in the hospital. Patients are free to walk around with the wireless transmitter.

The medical industry isn’t asking for a ban on all unlicensed TV white spaces. Rather, GE and others are seeking a compromise of sorts, in which certain channels would be off-limits, and device operators would be required to alert hospitals and other medical centers before deploying them nearby.

GE, for its part, would like to see the FCC continue to block off not only channel 37 but also adjacent channels 36 and 38, in an effort to create a greater buffer for its devices. It also wants the FCC to require new white spaces users to refrain from releasing new devices that use another popular location for medical telemetry devices–channels 33 to 35–for one year after any rules are developed. In addition, it’s asking for the FCC to limit the power output of the new devices to reduce interference potential.

The American Society for Healthcare Engineering, a division of the American Hospital Association, has also weighed in, asking the Federal Communications Commission to require that anyone operating devices in the unused TV channels notify hospitals, nursing homes and other health facilities within range of the signals beforehand.

Google, for its part, has already embraced at least some of those suggestions, proposing in a recent filing with the FCC that unlicensed white spaces be prohibited from operating in a “safe harbor” between channels 36 and 38, specifically citing concerns over medical telemetry devices.

Brian Peters, a spokesman for the Wireless Innovation Alliance, which is pushing for the unlicensed white-space use, said discussions with GE are “ongoing” and voiced confidence that they can reach an agreeable solution that allows for unlicensed use of mobile broadband devices. “We are also fully confident that the FCC engineers can write the rules necessary to prevent interference to medical devices,” Peters said in an e-mail interview with C/Net.

Wireless Innovation Alliance members include Google, Microsoft, Dell and HP, and consumer advocacy groups like Public Knowledge, U.S. Public Interest Research Group, and Free Press.

The National Association of Broadcasters, of course, are provided free use of VHF and UHF frequencies for “public service”. They are opposed to anyone using their unused channels.

The FCC is currently retesting early-stage “white space” equipment.

Interference by the proposed “white space” transmitters would be prevented in two ways:

“Sniffing” the spectrum for transmitters
Checking a GPS-linked database for nearby transmitters.

The FCC is not expected to issue any rules for the white spaces for several months. Even then, the spectrum won’t be available for use until at least February 2009, when over-the-air broadcasters are required to vacate that band as part of the congressionally mandated shift to all-digital television.