Originally featured on BroadcastEngineering.com
MSTV, Motorola trade charges over white space prototype test
The battle over allowing unlicensed TV band white space devices into the spectrum used for television and wireless mic transmission continued last week with charge and countercharge coming from the competing camps.
David Donovan, president of the Association for Maximum Service Television (MSTV), issued a statement May 16 saying a prototype device from Motorola being tested by the FCC “failed to adequately detect DTV signals.”
“According to yesterday’s tests, the device failed to accurately sense a DTV signal when there was a strong or even moderate DTV signal operating on the next channel, a situation that will occur in markets across the country,” he said.
Within hours of the release of the MSTV statement, Motorola responded. “The [MSTV] release claims that our device failed testing; however, the device test was fully successful and did detect DTV signals in the presence of strong adjacent channels at levels that will fully protect viewable television signals,” Steve Sharkey, Motorola senior director of regulatory and spectrum policy, said in a written statement.
According to Sharkey, the Motorola device relies on series of protective measures, including a geolocation database, spectrum sensing and beacon detection. This multitiered approach “is extremely reliable and will fully protect the television viewing public,” he said.
However, the bottom line is detection of DTV signals, Donovan said. In the MSTV statement, he said detection is “a critical issue because there will be multiple DTV signals operating in every market after the transition.”
Eliminating the risk of interference from white space devices is also critical to TV newsgathering, which relies on wireless microphones that are authorized to operate in the TV band.