Shure, the country's dominant wireless microphone maker, said Sept. 4 the Federal Communications Commission's recent proposal to ban all wireless mics from the 700MHz spectrum band comes as no surprise to the company.
"We've seen this coming for some time," said Mark Brunner, Shure's senior director of public and industry relations. "In fact, we have consciously been moving out of the band for seven years."
The FCC ordered a freeze Aug. 21 on the granting of any equipment authorization requests for wireless microphones that would operate in any of the 700MHz band frequencies. In addition, the FCC is considering a ban on any wireless microphones operating in the space.
The FCC proposed new rules for the operation of wireless microphones as part of the digital television transition set for Feb. 17 of 2009. After that date, television stations must broadcast in digital. To facilitate the transition, broadcasters have been allocated Channels 2 to 51. The remaining channels-popular spots for wireless mics-of the traditional broadcast spectrum, Channels 51 to 69, have been auctioned off for use of advanced wireless services.
Under the proposed FCC rule, wireless microphones would be limited to the spectrum spaces between Channels 2 to 51.
"These actions would ensure that low-power auxiliary operations do not cause harmful interference to new public safety and commercial wireless services in the band," the FCC proposed order stated.
Brunner stressed that the FCC was only proposing the rule and that persons operating wireless microphones in the spectrum of Channels 51 to 69 could still do so legally. Nevertheless, the Shure Web site warns users: "Wireless microphones that operate on frequencies above 698MHz [Channels 51 to 69] should not be used after Feb. 19, 2009."
Added Brunner, "We've known about this for some time and have been behaving and cooperating with the FCC's intent. We have been anticipating this."
Moving to the new spectrum, though, is fraught with potential interference problems for wireless microphone users. Google, Microsoft, Motorola and other tech companies want to move into the same interference buffers, known as white spaces, between Channels 2 and 51 in order to deliver wireless broadband and other advanced services.
Sports organizations like the NFL and MLB, along with entertainment operations, churches and nightclubs that use wireless microphones, maintain that the unlicensed use of white spaces will cause interference with the use their wireless microphones.
"This is pivotal spectrum for wireless microphones," Brunner said.
The FCC began testing white spaces devices with mixed results in January using a prototype device supplied by Microsoft. In July, the agency moved the tests outdoors using devices from Motorola, Philips, Adaptrum and InfoComm International. After the outdoors testing, Motorola declared the tests a success, while Shure said the tests were a failure.
"Simply stated, the prototype devices were unable to consistently identify operating wireless microphones or distinguish occupied from unoccupied TV channels," Brunner said in August.
Motorola's device combined sensing technology with geolocation to find existing channels and route signals around the channel. Motorola, however, did not participate in the testing of white spaces and wireless microphones.
The Wireless Innovation Alliance, a group of tech companies promoting the use of unlicensed white spaces devices, also declared the tests a success.
"Just as the bench testing has shown time and time again, the science behind spectrum sensing is sound. The current field tests, including Saturday's [Aug. 9] test at FedEx Field, have done nothing to contradict the previous results," said Jake Ward, a spokesperson for the Alliance. "The FCC has the information it needs to move forward with their final report and the development of rules of the road for white space technologies."