New tests show GPS interference with LightSquared test gear; opponents suggest moving the 4G network out of the L-Band

Dan Jones, Mobile Editor

June 10, 2011

2 Min Read
LightSquared Opposition Wants Spectrum Shift

Opponents to the proposed LightSquared Long Term Evolution (LTE) network in the L-Band are now suggesting that the Federal Communications Commission (FCC) find a different swathe of spectrum for the proposed wholesale 4G network.

LightSquared plans to build out the first wide-scale, hybrid LTE terrestrial and satellite network using L-Band spectrum. The 1.6GHz L-Band, however, sits adjacent to frequencies used by global positioning satellites (GPS) to broadcast triangulated location data to earthbound receivers.

The GPS industry and several government bodies are worried that the powerful signals from earthbound LTE towers will be picked up by GPS receivers, swamping weaker broadcasts from space.

To that end, the National PNT Engineering Forum has issued new data that suggests that the LightSquared equipment weakens some receivers' ability to get positioning data and swamps some others entirely. The committee's suggested fix is to put LightSquared on different spectrum or add new filters to the GPS receivers.

Speaking at an event sponsored by the PNT Board Thursday, Jim Kirkland, vice president and general counsel of Trimble, a founding member of the Coalition to Save Our GPS suggested that the FCC should find new spectrum for the startup instead:

"The test data discussed today [Thursday] makes clear that there is substantial interference to GPS if LightSquared turns on high-powered terrestrial facilities in the spectrum next door to GPS," Kirkland said in a statement.

"The data confirms what the industry told the FCC before it granted the waiver, and also confirms that there is no viable technical fix," he continued. "It's time for the FCC to stop squandering resources trying to find a solution to an unfixable problem. Instead, it should focus its efforts on finding spectrum that LightSquared can operate in -- where LightSquared won't interfere with GPS."

Why this matters
This wireless battle is going down to the wire.

LightSquared recently said it was open to all options when it comes to fixing GPS options but suggested that the GPS industry has known for years that the FCC was opening the L-Band for terrestrial use. Meanwhile, the GPS players want a spectrum shift for LightSquared, not -- it appears -- additional filters for GPS receivers.

The final report on GPS testing will be out next week. The FCC is set to review the report and coordinate with other government agencies after that.

For more
See more on the vexed issue of GPS interference.

  • LightSquared Nears the End of GPS Testing

  • LightSquared GPS Fix Could Cost 'Billions'

  • LightSquared: GPS Issues Won't Stall Launch

  • Pentagon Calls Interference on LightSquared

  • FCC Lets LightSquared Pass 'Go'

  • LightSquared Confident in Q3 Launch Schedule

  • LightSquared Files First Report to FCC

  • LightSquared Gets Satellite-Ready



— Dan Jones, Site Editor, Light Reading Mobile

About the Author(s)

Dan Jones

Mobile Editor

Dan is to hats what Will.I.Am is to ridiculous eyewear. Fedora, trilby, tam-o-shanter -- all have graced the Jones pate during his career as the go-to purveyor of mobile essentials.

But hey, Dan is so much more than 4G maps and state-of-the-art headgear. Before joining the Light Reading team in 2002 he was an award-winning cult hit on Broadway (with four 'Toni' awards, two 'Emma' gongs and a 'Brian' to his name) with his one-man show, "Dan Sings the Show Tunes."

His perfectly crafted blogs, falling under the "Jonestown" banner, have been compared to the works of Chekhov. But only by Dan.

He lives in Brooklyn with cats.

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