Download - Coordinates

GPS
LightSquared and GPS
The controversy around LightSquared and GPS has been summarized below
What is LightSquared?
LightSquared Subsidiary LLC is a
company that plans to provide a wholesale,
nationwide 4G-LTE wireless broadband
network integrated with satellite coverage.
LightSquared will combine existing
mobile satellite communications services
(formerly known as SkyTerra) with a
ground-based wireless communications
network that uses the same L-band radio
spectrum as the satellites. On January
26, 2011, the Federal Communications
Commission (FCC) issued an Order
and Authorization giving LightSquared
conditional approval to build out its
ground-based wireless network (referred
to as an ancillary terrestrial component,
ATC) by reusing its authorized mobile
satellite service (MSS) spectrum. The
approval is subject to further testing
and FCC review (see below).
GPS community concerns
The base stations of the LightSquared
network will transmit signals in a radio
band immediately adjacent to the GPS
frequencies. The GPS community is
concerned because testing has shown that
LightSquared’s ground-based transmissions
overpower the relatively weak GPS signal
from space. Although LightSquared will
operate in its own radio band, that band is
so close to the GPS signals that most GPS
devices pick up the stronger LightSquared
signal and become overloaded or jammed.
There is also concern that the FCC may
approve a technical solution to the problem
that requires millions of existing GPS
users to upgrade or replace their devices.
What is being done to
address the concerns?
In its Order and Authorization, the FCC
required that LightSquared create a
12 | September 2011
working group with the GPS community
“to address interference concerns regarding
GPS and, further, that this [working
group] process must be completed to
the Commission’s satisfaction before
LightSquared commences offering
commercial service.” LightSquared
committed $20 million to the working
group and worked closely with the U.S.
GPS Industry Council and other participants
to complete interference testing.
The FCC ordered LightSquared to file
monthly progress reports and a final
report due June 15, 2011. On June 15,
LightSquared requested and the FCC
approved an extension of the deadline
to July 1, 2011. They submitted their
final report on June 30, 2011, along
with a separate document providing
their recommendation to the FCC.
The FCC opened a 30-day public
comment period on the report and
recommendations, with a comment
deadline of July 30, 2011. LightSquared
cannot commence commercial operations
of its terrestrial network until the FCC,
“after consultation with NTIA [National
Telecommunications and Information
Administration], concludes that harmful
interference concerns have been resolved
and sends a letter to LightSquared
stating that the process is complete.”
Independent of the FCC-ordered study,
the government’s National Space-Based
PNT Systems Engineering Forum (NPEF)
conducted its own testing of the potential
interference to military and civilian GPS
users from LightSquared’s terrestrial
network. The NPEF completed its report
on June 1, 2011; the unclassified public
version was released July 6, 2011.
What is the Executive Branch
position on this issue?
The government GPS community is
working closely with LightSquared and
the U.S. spectrum regulators to ensure that
GPS users are protected from interference
and unnecessary re-equipage. The
U.S. Government continues to support
the President’s National Broadband
Plan and facilitate its implementation
consistent with the preservation of
national and economic security.
Federal agencies have conducted extensive
technical studies to understand the
interference effects and seek potential
mitigations. Their initial analysis is
complete and was provided to the FCC
through the National Telecommunications
and Information Administration (NTIA).
The results clearly demonstrate that
implementing LightSquared’s planned
deployment for terrestrial operations
poses a significant potential for harmful
interference to GPS services.
Prior to the FCC Order and Authorization
of January 2011, the National Coordination
Office and multiple federal agencies
expressed concern about potential GPS
interference from LightSquared. On
behalf of the Executive Branch, NTIA
sent a letter to the FCC stating that the
LightSquared proposal raised “significant
interference concerns that warrant full
evaluation” to ensure that federal agencies’
use of GPS is not adversely impacted.
On July 6, 2011, the NTIA Administrator
sent another letter to the FCC stating
that, based on the government testing
and analysis, his earlier concerns about
GPS interference remain unresolved. He
recommended that the FCC continue to
withhold authorization for LightSquared to
commence commercial operations. NTIA,
in coordination with federal agencies,
is still reviewing the LightSquared
working group test results and will
continue to consult with the FCC.
www.pnt.gov/interference/lightsquared/