The GPS
industry’s failure to comply with the Department of Defense’s (DoD) filtering
standards is the root cause of potential interference issues involving
LightSquared’s proposed broadband wireless network, LightSquared executive vice
president for Regulatory Affairs & Public Policy Jeffrey Carlisle wrote in
a letter filed today at the Federal Communications Commission (FCC).
“Had the
GPS industry complied with DoD’s recommended filtering standards for GPS
receivers, there would be no issue with LightSquared’s operations in the lower
portion of its downlink band,” Carlisle stated in the FCC filing.
The DoD’s
Global Positioning System Standard Positioning Service Performance Standard,
issued in September 2008, calls for GPS receivers to filter out transmissions
from adjacent bands in order to achieve the performance intended to be provided
by the GPS system.
In addition to
ignoring the DoD standard, the GPS industry also has spurned international
recommendations for GPS receiver design. Since 2000, the International
Telecommunication Union (ITU), the United Nations agency that sets
international standards for radio and satellite spectrum, has cautioned that
“a more stringent pre-correlator filter may be needed to protect [GPS]
receiver operations from adjacent band RF emissions.”
The DoD
standard, in effect, grants GPS a 4 MHz “guard band.” Now, however,
the GPS manufacturers are rejecting LightSquared’s offer of a 23 MHz guard band
that would be created by LightSquared’s decision to begin its terrestrial
operations in the lower half of the downlink band.
Instead, the
GPS industry unreasonably insists on a 34 MHz guard band – 8.5 times as wide as
the DoD recommendation.
“If all
spectrum users demanded the irrational guard band solutions that GPS
manufacturers are demanding, we would not have broadband in this country and
efficient spectrum use would take a backseat to the squeakiest wheel,”
Carlisle said. “This type of precedent would set back the United States’
competitiveness by decades. The GPS industry turned a blind eye to the
Department of Defense’s recommendations regarding the manufacturing of
commercial GPS receivers and a blind eye to the ITU’s long-standing
recommendations regarding GPS receiver performance.”
Given the DoD’s
clear recommendations and the long-standing ITU warnings, it is not credible
for the GPS industry to now claim that it is not responsible for the flawed
design of its receivers. By demanding that LightSquared be prevented from
building a ground service that has been authorized for years, the GPS
manufacturers are simply trying to formalize squatting for free on someone
else’s licensed spectrum.
The GPS
industry has a responsibility to use its licensed spectrum in accordance with
international and federal government standards not for LightSquared’s sake,
but for the sake of the American people who own the public airwaves and who
fund the GPS satellite system.
“The GPS
industry benefits from an estimated $18 billion taxpayer subsidy to offer
a commercial service that is completely dependent on a government
satellite system. Despite the federal handout, they
have deliberately ignored Defense Department criteria for using the
restricted system,” Carlisle said. “LightSquared remains
committed to working in partnership with responsible members of the GPS
industry and for the benefit of the public by creating good-paying jobs and
economic opportunity at a time when America desperately needs both.”
By Telecomlead.com Team
editor@telecomlead.com
