Page 55 - Volume 15 Number 9

NATIONAL BUSINESS AVIATION ASSOCIATION • focus
NBAA and Other GA Groups Working to Stave of Threats to GPS Service
Despite clear evidence that 4G broadband Lawmakers in the United States have protested
signals would compromise the integrity
of Global Positioning Systems (GPS) receivers on adjacent spectrum, an announcement from the Federal Communications Commission (FCC) in early August said only that a decision about whether to allow such a 4G network will likely not come as soon as the wireless industry had initially hoped.
During an August 9 press conference, FCC Chairman Julius Genachowski said the agency never committed to a specific timeframe to decide on plans by telecommunications provider LightSquared to develop a 4G broadband network, despite industry expectations the ruling would occur by mid-September. Whenever that decision comes, Genachowski said it would be “fact-based” and “engineering- based,” he told reporters.
LightSquared’s proposed communications network promises to dramatically increase access to mobile satellite spectrum (MSS) signals used by laptop computers and smartphones. The FCC approved a conditional waiver in January 2011 for field trials of the technology, over concerns from the GPS industry and after tests by industry experts, including LightSquared’s own research, revealed significant levels of interference from the 4G signal.
While LightSquared moves ahead with its plans, Genachowski has attempted to allay industry fears that LightSquared would be given carte blanche to dominate GPS bandwidth. “We’re not going to do anything that creates problems for GPS safety and service as we explore technical solutions that will both protect GPS and allow a new service to launch,” he stated at the news conference.
LightSquared’s plans, with nearly 100 House and Senate representatives calling for the FCC to pull the conditional waiver until the provider’s technology can be proven to safely coexist with GPS signals. The International Civil Aviation
Organization (ICAO) has expressed similar misgivings.
With pressure mounting, LightSquared has suggested moving to bandwidth further away from GPS, though still within the L-band spectrum, and for GPS manufacturers to add filters to reduce 4G interference to GPS receivers. Critics maintain neither
proposal would solve the issue.
“There’s no such thing as building a wall around bandwidth,” explained Bill Stine, Director of International Operations for the National Business Aviation Association (NBAA). “A GPS receiver needs to pull a very weak signal out from the clutter of noise on a frequency, and LightSquared’s signal is unbelievably stronger
than the GPS signal.”
NBAA is among more than 200 members of the Coalition to Save Our GPS, a group dedicated to preserving the safety and integrity of the nation’s GPS network.
LightSquared eventually acknowledged to the FCC that its signal would interfere with GPS, but rather than providing alternatives, the company went on the offensive. In a June 30 release, LightSquared termed a crisis “a problem of their own making” caused by “the GPS device manufacturer’s decision over the last eight years to design products that depend on using spectrum assigned to other FCC licensees.” m
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