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Tests show proposed wireless network could jam GPS

WASHINGTON — New government test results show that a proposed high-speed wireless broadband network could jam aspects of the Global Positioning System, used for everything from aviation to public safety and military operations.

The results released Friday by a federal working group come amid mounting concern that LightSquared's planned network could cripple GPS networks embedded throughout the nation's infrastructure, some of which are critical to national defense.

"LightSquared's network could cause devastating interference to all different kinds of GPS receivers," said Jim Kirkland, vice president and general counsel of Trimble Navigation, which makes GPS products.

In January, the Federal Communications Commission gave LightSquared approval to build a nationwide fourth-generation wireless network that would compete with super-fast systems being rolled out by AT&T and Verizon. The new network will wholesale access to other companies that will rebrand the service under their own names. It would cover at least 92 percent of the United States by 2015.

The FCC sees the LightSquared network as one part of a broad government push to bring high-speed Internet connections to all Americans.

The company's plans have set off alarm bells among GPS equipment makers and the many government agencies and companies that rely on GPS, because LightSquared's network would use airwaves right next to those already set aside for GPS. The concern is that sensitive satellite receivers — designed to pick up relatively weak signals coming from space — could be overwhelmed when LightSquared starts sending high-powered signals from as many as 40,000 transmitters on the ground.

Test results were compiled by a working group of the National Executive Committee for Space-Based Positioning, Navigation, and Timing — a government organization that advises and coordinates among federal agencies that rely on GPS technology. It found that wireless signals from LightSquared's planned network interfered with GPS receivers used by the Coast Guard and NASA. They caused Federal Aviation Administration GPS receivers to stop functioning altogether.

Last week, RTCA, a nonprofit group that advises the FAA, released the results of its own interference tests and found that LightSquared's use of airwaves closest to the GPS spectrum would cause a "complete loss of GPS receiver function" over large metropolitan areas.

Faced with these concerns, the FCC has made clear that LightSquared cannot launch its network until the interference issues are resolved. It is requiring the company to participate in a technical working group with GPS manufacturers and users to study the matter.

In a statement Friday, the FCC said it "will not allow LightSquared's commercial service to proceed if that would cause widespread harmful interference with GPS."

LightSquared executive vice president Jeffrey Carlisle said he remains confident that the company's new network and GPS networks can co-exist. After all, he noted, findings of interference do not come as a surprise. What matters, he said, is what can be done about the interference.

Tests show proposed wireless network could jam GPS 06/10/11 [Last modified: Friday, June 10, 2011 10:22pm]
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