NTIA Releases LightSquared GPS Interference Study
July 11, 2011
WASHINGTON: A federal report documenting GPS interference by
the proposed LightSquared satellite-terrestrial broadband network has been
released. The National Telecommunications and Information Administration recommended
that the project remain on hold until the problem is solved.
“NTIA supports EXCOM’s recommendation that additional tests be performed and
recommends that the FCC continue to withhold authorization for LightSquared to
commence commercial operations until all the available test data can be
analyzed and all valid concerns have been resolved,” said NTIA chief Larry
Stricking in a letter to Julius Genachowski, head of the Federal Communications
Commission, which green-lighted LightSquared in January. EXCOM is the National
Executive Committee for Space-Based Positioning, Navigation and Timing, which
directed the report.
It said multiphase tests of LightSquared’s proposed terrestrial transmitters
demonstrated “significant detrimental impacts to all GPS applications”
evaluated, including government and commercial uses. A simulation of the
completed network of base stations “would result in degradation or loss of GPS
function at standoff distances of a few kilometers extending to space
operations,” it said.
The interference issue starting dogging LightSquared soon after it started
testing transmitters. It filed a modified operational plan with the FCC June
30, taking issue GPS receiver quality. (
Blasts GPS Receiver Quality.”) The company noted that GPS receivers do
not adequately reject adjacent-band interference and should be made to do so
per FCC rules.
The EXCOM test also observed that GPS receivers could be modified to reject
interference, but that it would be “impractical, as they would require
significant modification or complete redesign and replacement of currently
fielded GPS equipment.
“The timeline to field new GPS receivers for some applications, from initial
concept development through production, can take 10-15 years.”
The report urged the feds to conduct more thorough studies on LightSquared’s
proposed network, including alternative signal configurations and handset
transmissions. It recommended an additional evaluation period of “at least six
LightSquared, in the meantime, is burning through cash awaiting for regulator
approval. The company is funded through venture capital from Harbinger Ventures
and private contributions from Harbinger’s principal, Philip Falcone. UBS and
JP Morgan have also invested. The company last week announced having raised an
additional $265 million from existing and new investors. It expects to sink $14
billion of private money into the network over an eight-year period.
The EXCOM report, “Assessment of LightSquared Terrestrial Broadband System
Effects on GPS Receivers and GPS-dependent Applications,” is at the
Deborah D. McAdams