Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now


Wireless Mics Concern Radio STL Users

Reallocation of Some UHF Spectrum Could Result in Scramble

LOS ANGELES Concerned about what they describe as misleading information from at least one wireless microphone dealer, the Society of Broadcast Engineers and others in the broadcast industry are worried that interference within spectrum used for STL paths could increase significantly by early next year.

Two complaints against Location Sound Corp. of North Hollywood, Calif., have been filed with the Federal Communications Commission regarding the company’s marketing.

In a recent newsletter, the company encouraged non-broadcasters to use 944–952 MHz for wireless microphone applications.

However, only broadcast licensees and broadcast networks can operate devices in 944–952 MHz, and the band is used extensively by radio broadcasters for licensed aural studio-to-transmitter links.

The reallocation of analog UHF Channels 52–69 from the 700 MHz band will result in a severe reduction of available spectrum for Part 74, Subpart H Low-Power Auxiliary equipment including wireless microphones, industry experts said. Non-licensees have long used 700 MHz for wireless mic operation on vacant TV channels. In February it will become illegal to market or sell 700 MHz band wireless mics in the United States.

Public safety and commercial broadband applications are moving to 700 MHz on Feb. 17, 2009, a move coinciding with the country’s digital television conversion.

Industry observers say as spectrum is pinched for wireless mic users being booted from 700 MHz, broadcasters must be vigilant during what could be a scramble for spectrum.

In addition to the complaints against Location Sound Corp., the SBE posted a statement on its Web site saying that the society is aware of manufacturers producing and selling wireless mics to ineligible parties that operate in the 950 MHz Aural Broadcast Auxiliary Service (BAS) band.

‘Illegally operate’

“The active marketing, sale or leasing to ineligible or unlicensed persons is wrong and unlawful and endangers reliable broadcast and BAS operation,” SBE states in the letter. “SBE will provide assistance and serve as a resource to the FCC Enforcement Bureau in locating entities who illegally operate Part 74 wireless microphones without benefit of the required FCC license.”

Richard Rudman, chairman of the Southern California Frequency Coordinating Committee, was one of the first to notice the article in Location Sound’s newsletter. The company stated that the “little-known area of UHF spectrum (944–952 MHz) is, for the most part, wide-open and available for production use.” Rudman described Location Sound Corp. as a well-established distributor that caters to the TV and film production industry and sells nationally.

In a world of crowded spectrum, with some broadcasters in urban areas already struggling to find space in the 950 MHz band for STL links, anything viewed as a spectrum grab should be met with strong resistance, Rudman said.

He filed an official complaint in September with the FCC about Location Sound’s statements. Rudman also suspects Location Sound previously conducted unauthorized transmissions in the band at Universal Studios. Though the FCC field office in Los Angeles took no immediate action, the complaint was forwarded to its Enforcement Bureau in Washington, Rudman said.

Location Sound, in an e-mail response distributed to several parties including Rudman, stated that it now realizes the company should not have made claims that the 944¬–952 STL band is available for wireless mics by unlicensed users, Rudman said.

“After consulting with our vendors who manufacture products in the 944 MHz band, we have come to the conclusion that Location Sound Corp. will immediately cease marketing wireless microphones that operate in the 944 MHz band to our customers who would be generally classified as motion picture or television producers,” wrote Mike Paul, technical director for Location Sound, in the e-mail to Rudman.

Location Sound also promised to follow up with Universal City, Rudman said.

Efforts to reach Location Sound representatives for comment on this story were unsuccessful.

‘Spectrum chaos’

“I do not think the FCC yet realizes the predicament many wireless mic users, such as bands, theaters, churches, clubs and production companies will face if 700 MHz use goes away as the FCC intends,” Rudman said.

“Either we have a world where FCC license requirements are enforced, or we invite further spectrum chaos if they are not.”

Dane Ericksen, senior consulting engineer with Hammet & Edison, said, “You have a whole pot full of wireless mic users being booted in February from 700 MHz. Some are legal users and others are illegal. However, I believe that the FCC will begin strict enforcement once public safety moves to 700 MHz,” Ericksen said. “FCC non-enforcement has been an issue for years.”

To make matters more confusing, he said, some wireless mic manufacturers appear to be marketing to ineligible groups.

“Part of the confusion is that there are Part 15 wireless mics that are in the 902–928 MHz band and they’re perfectly okay,” Ericksen said. “Unscrupulous dealers could take advantage of the complexity of the issue.”

While the 944–952 STL band in major radio markets, with its limited white space, would seem the most susceptible to interference from unlicensed wireless mic users, smaller radio markets could experience problems, too, said Thomas Ray, corporate director of engineering for Buckley Radio and WOR(AM) in New York, a Radio World contributor.

“I’m more concerned with what will happen in the Midwest where you have hops of 20 to 50-plus miles to the transmitter facility,” Ray said.

Ray said he is unaware of any broadcasters experiencing interference with their 950 MHz STL paths in New York City. That’s despite the theater district’s proximity to 4 Times Square and the Empire State Building, where the vast majority of the city’s FM stations have transmission facilities.

“There is a huge potential for problems here though, particularly near the city’s theater district, where every theater is using wireless mics,” Ray said.

The mobility of wireless mics makes it more difficult to track down sources of interference when it does occur, said other RF experts.

“Each day radio broadcasters everywhere experience unexplained interference. Was it a wireless mic? Was it a bird? Ice? Heat? Was it the green insulator atop a power company transmission tower? There is no way of knowing,” said Ralph Beaver, SBE board member and CEO of Media Alert LLC.

SBE firmly believes the 944–952 MHz Aural BAS band is already heavily occupied in most areas of the United States, Beaver said, and offers little capacity for operation of wireless microphones by eligible licensees and no options for unlicensed or ineligible licensees to use the spectrum.

“That is contrary to what some vendors of wireless microphones are saying,” Beaver said.