Initial testing by the Federal Communications Commission (FCC) has
resulted in a thumbs down for prototype devices designed to exploit the
empty spectrum between television channels.
Technology companies such as Microsoft and Google hope to use these
interference buffer zones, known as “white spaces,”
to develop both licensed and unlicensed
wireless devices and services. Licensed use could include delivering
Free, unregulated spectrum is currently used by garage-door openers, baby monitors, microwave ovens, remote controls
and, increasingly, wireless LANs.
“Prototype white space devices submitted to the commission for initial
evaluation do not consistently sense or detect TV broadcast or wireless
microphone signals,” a new FCC report states.
According to the report, the first prototype was “generally unable” to
sense wireless microphones while the second device delivered mixed results.
Despite the disappointing results, the FCC said it was still open to the
possibilities of using white space spectrum. “The devices we have tested
represent an initial effort, and do not necessarily represent the full
capabilities that might be developed with sufficient time and
resources,” the report states.
The White Spaces Coalition that includes Microsoft
“Coalition members are encouraged that FCC engineers did not find fault
with our operating parameters and remain confident that unlicensed
television spectrum can be used without interference,” the group said in
a statement. “In fact in its report, the FCC stated that ‘the bench test
results indicate that under laboratory conditions, this device is
generally able to reliably detect DTV signals.”
The National Association of Broadcasters (NAB), which has long opposed
unlicensed use of white spaces, said the report supported their view.
“FCC testing results confirm what NAB…and others have long contended:
that the portable, unlicensed devices proposed by high-tech firms can’t
make the transition from theory to actuality without compromising
interference-free television reception,” NAB Executive Vice President
Dennis Wharton said in a statement.
Although broadcasters have allocated hundreds of megahertz of spectrum in
every U.S. television market, significant chunks are unused, serving as
buffers against interference from other channels. In Boston and Chicago,
for instance, almost 50 MHz is fallow.
The unused spectrum is considered ideal for wireless broadband because
the radio signals penetrate walls and other objects.