Motorola has delivered and demonstrated a prototype white space device (WSD)—or, as Motorola calls it, a Cognitive Radio Device—to test whether it can sense, and thus avoid, interfering with DTV signals.
Motorola officials gave the device to FCC Office of Engineering and Technology staff at a meeting Nov. 15 and dropped off a two-page sheet of instructions for operating and testing the device. Motorola previously demonstrated a prototype device to FCC staff Aug. 30.
In an FCC filing, the company said the device uses a "geolocation database that is augmented by sensing algorithms" to determine which TV channels are available for use.
Motorola has proposed a two-tier regime for devices that would operate in the DTV white spaces or, as some broadcasters call them, "interference zones." Under Motorola's plan, fixed, licensed devices would use geolocation databases to help find usable channels, while lower-power devices would operate using spectrum sensing technology, but not the geo-location database.
Broadcasters, citing DTV interference concerns, have opposed rules that would allow mobile, unlicensed devices in the DTV space. Several high-tech companies, including members of the White Space Coalition, say the spectrum could be used for a new generation of consumer devices form home networking tools to portable media centers.
Microsoft and Philips, members of the White Space Coalition, have already submitted prototype devices for FCC test that aim to help the commission make the rules, and both companies have called for further tests of modified devices after their poor performance in initial FCC tests this summer. The FCC in October announced it would conduct more tests, but has been mum about the specific tests of devices involved.
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