Wireless microphone maker Shure says it has been anticipating Federal Communications Commission rules banning the use of wireless microphones in the 700MHz spectrum for years. Problems, though, still remain for wireless microphone users as the FCC proposes limiting use of the devices to the interference buffer zones between Channels 2 and 51, the same space being eyed by Google, Microsoft, Motorola and other tech companies for the delivery of unlicensed wireless broadband and other advanced services.
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,
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
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.
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
"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."