There’s a historic vote coming Nov. 4. FCC Chairman Kevin Martin has outlined his plan for the use of devices on the unused DTV channels used at white spaces, potentially spawning major new developments in consumer devices and wireless Internet access.
The issue is on the commission’s agenda for its meeting Nov. 4—Election Day—although Martin has habitually placed items on the agenda in the hopes of having a majority of votes, only to yank them at the last moment when the votes did not materialize.
The long-awaited report from the FCC Office of Engineering and Technology, describing its tests on the technical issues of potential white space devices, was released Wednesday evening. In a conference call with reporters, Martin provided some details on the proposed order, which would allow enormous use of unlicensed devices and potentially spawn billions of dollars in equipment and content-delivery opportunities.
Under the plan, the FCC heeded the wishes of the White Spaces Coalition (a group of large high-tech companies) that there would be no auction and licensing of the spectrum. Portable devices that use both spectrum-sensing technology and geolocation databases to prevent interference to DTV would be limited to 100 mW of power, or 40 mW when operating on channels adjacent to active DTV channels.
If the devices used only sensing-spectrum policy, they would be limited to 50 mW, or 40 mW on adjacent channels.
Fixed devices would operate at a maximum of 4 W, and not at all on adjacent channels unless they can show to the commission that they can avoid interfering with DTV.
The power limits comes close to a recent proposal by Google. Its regime would rely on geolocation but not spectrum sensing. For non-adjacent channels, it proposed maximum power levels of 36 dBm (about 4 W) for fixed devices and 20 dBm (100 mW) for portable devices.
The Association for Maximum Service Television has called for lower power levels. MSTV wants no fixed devices in adjacent channels and portable devices at just 5 mW on those channels and 10 mW on the other channels.
MSTV also said Google’s approach “has not been examined, much less tested by the FCC.”
Martin said that while tests had shown “proof of concept” of spectrum-sensing, manufacturers would still have to subject devices to FCC Office of Engineering and Technology to show that the spectrum sensing works. Broadcasters have said spectrum sensing doesn’t work.
He did not mention so-called beacon technology to protect wireless mic use, a concept opposed by broadcasters and mic users.
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