LightSquared Tests Spectrum Sharing
Granted experimental authority to operate in meteorological spectrum
May 8, 2013
is testing the feasibility of sharing spectrum with federal users. The bankrupt
venture won approval from the Federal Communications Commission recently for
experimental authority to test wireless broadband at 1,675-1,680 MHz on a
shared basis with existing federal meteorological users. The authorization reflects
a November, 2012, petition filed by LightSquared to operate the terrestrial component
of its proposed network in this 1.6 GHz allocation rather than the 1,545-1,555 L-band
spectrum where its operations were found to interfere with global positioning
“LightSquared proposes that this additional use of the 1,675-1,680 MHz band be
permitted only if such use is coordinated to protect government systems that
will remain in the band-including the critical weather monitoring and predicting
operations of the National Oceanic and Atmospheric Administration,” the
Speaking Wednesday at an investors’ conference in New York, outgoing FCC
Chairman Julius Genachowski said he expects LightSquared to eventually win
approval to use its spectrum for a terrestrial broadband network, according to
It was under Genachowski’s watch in January of 2011 that LightSquared
secured an FCC waiver allowing it to develop a terrestrial operation in the
L-band spectrum designated primarily for satellite transmissions. The company’s
goal was to create a nationwide 4G LTE hybrid terrestrial-satellite wireless
broadband network to offer on a wholesale basis to consumer-facing carriers.
Subsequent tests indicated that terrestrial signals interfered with GPS devices
in adjacent spectrum, or rather, GPS devices lacked the ability to reject
LightSquared offered to operate at a lower power level on only half of its
spectrum, creating a buffer zone for GPS operations, but further tests by the
Executive Committee for Space-Based Positioning, Navigation and Timing Systems
Engineering Forum indicated that high-precision GPS devices—such as those used
by the military—would still be affected.
LightSquared countered with its own test results from Alcatel
Lucent, and offered to fabricate filters for sensitive GPS devices, but the
outcry from the GPS community was overwhelming. Comments continue to compile on
the FCC’s LightSquared
docket, even though the commission suspended the terrestrial waiver more
than a year ago.
Within a few months, the company, funded with around $3 billion from New
York-based hedge fund Harbinger Capital, filed for Chapter 11 in U.S.
Bankruptcy Court for the Southern District of New York. Lawmakers followed with
on how LightSquared secured the terrestrial waiver in the first place, and have
since turned their attention to receiver
LightSquared’s current proposal, and the subject of the experimental authority,
is to initiate a rulemaking to add a non-federal, terrestrial mobile use
allocation to the 1,675-1,680 MHz band. If granted, LightSquared would use the
1,670-1,680 MHz band for downlinking, and two more 10 MHz allocations in the
1.6 GHz band for uplink operations. It would relinquish its authority to
conduct terrestrial operations at 1,545-1,555, “providing GPS receivers an
additional 10 MHz guard band from terrestrial services,” the petition states.
The next step would be a Special Temporary Authority to determine the technical
feasibility, timing and cost of moving radiosonde devices to other frequencies.
The experimental license commenced April 29 and expires July 20, 2013.
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