LightSquared GPS interference cannot be solved, say federal agencies

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Proposed commercial broadband wireless service provider LightSquared received a possibly deadly blow with the Jan. 13 release (.pdf) of a letter from nine federal agencies concluding that the company's attempt to initially use lower frequency signals would still affect spectrum utilized by the Global Positioning Satellite system.

The agencies, which include the departments of Defense and Transportation, make up the National Space-Based Positioning, Navigation and Timing executive committee. The unanimous conclusion of testing done by the committee, the letter states, is that LightSquared's original and modified plan for rolling out a 4G LTE and satellite-signal nationwide network would cause interference problems with many GPS receivers. Analysis conducted by the FAA also finds that LightSquared proposals "are not compatible" with several GPS-dependent aircraft safety systems, the letter says.

"There appear to be no practical solutions or mitigations," the letter says.

As a result, "no additional testing is warranted at this time," it adds. The letter is signed by Deputy Defense Secretary Ashton Carter and Deputy Transportation Secretary John Porcari and addressed to National Telecommunications and Information Administration head Larry Strickling.

LightSquared, based in Reston, Va., responded that same day with a press release accusing the committee of being influenced by an advisory board with members who "have deep ties with the same GPS manufacturers who have sold poorly designed equipment to America's farmers, public safety officials, military and government agencies." The company has filed a complaint with the NASA inspector general office alleging conflict of interest, the press release adds.

It also sent a letter (.pdf) of its own to Strickling requesting that the NTIA order up more testing, to be conducted at an Alcatel Lucent facility leased by LightSquared.

The company filed a petition (.pdf) on Dec. 20 with the Federal Communications Commission arguing that the potential for interference to commercial GPS receivers is the fault of "unlicensed and poorly designed" receivers that infringe on the spectrum LightSquared licensed for its broadband network.

For more:
- download the Jan. 13 letter from the National Space-Based Positioning, Navigation and Timing executive committee (.pdf)

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