06.20.2008 09:10 AM
Originally featured on BroadcastEngineering.com
MSTV rejects coalition proposal for dual-layer protection of wireless mics
A proposal advanced this week by the White Space Coalition (WSC) to rely on spectrum sensing and a protection beacon to prevent interference with wireless microphones drew a sharp rejection from the Association for Maximum Service Television (MSTV).
The coalition sent a letter June 17 to the FCC saying it should require rules setting up additional protection for wireless mics, which share TV spectrum, from potential interference generated by unlicensed white space devices. In the letter, the coalition said it would “support a requirement that all white space devices include, in addition to spectrum sensing capability, the ability to recognize a wireless microphone protection beacon and to avoid the TV channel in which the microphone is operating whenever they encounter such a beacon.”
However, MSTV President David Donovan rejected the proposal. “Combining two defective approaches will not prevent interference,” he said.
“Millions of viewers are receiving critical information about levies breaking and emergency services,” he said in the statement. The use of wireless mics by news crews on the scene is producing information that “is saving lives,” he said.
The coalition proposal offers three elements of wireless mic protection, including:
- No use of spectrum below channels 21 to protect public safety bands in channels 14-20 and reserve channels for wireless mic use
- Spectrum sensing and dynamic frequency selection
- A beacon to protect wireless mics
In calling for the FCC to reject the proposal, Donovan said, “sensing does not work… none of the devices submitted to the FCC sensed wireless microphones.” He also pointed out that “essentially the same plan” has been rejected by IEEE 802.22 “because it would not provide sufficient protection to TV viewers and incumbent wireless microphone users.”
“Promises of non-interference based on proposals that have failed or been rejected by IEEE are not sufficient,” Donovan said.
To read the WSC proposal, visit http://www.wirelessinnovationalliance.org/files/Beacon%20ex%20parte%20FINAL.pdf.