PARIS — The company planning a satellite-terrestrial broadband wireless network in the United States using L-band radio spectrum continues to face pressure from a broad swath of U.S. government agencies that want the company’s plans to be put on indefinite hold pending a resolution of interference issues with the U.S. GPS navigation system.

Whether Reston, Va.-based LightSquared’s recent agreement to abandon, for now, use of the spectrum that is closest to GPS will be enough to clear regulatory approval is unclear.

The latest protest against LightSquared’s use of frequency close to spectrum used by GPS terminals came from the executive commission of the 27-nation European Union.

In a July 19 letter to the U.S. Federal Communications Commission (FCC), the European Commission expressed concern that Europe’s satellite navigation systems, Egnos — which uses U.S. GPS signals coupled with an overlay of satellites in higher orbit — and the future Galileo satellite constellation would be rendered useless in U.S. airspace if LightSquared goes forward.

The letter, written by Heinz Zourek, the director-general of the commission’s directorate for enterprise and industry, said navigation users are accustomed to having mobile satellite services next door to their spectrum. But the number and power of LightSquared’s likely users, the commission said, “would completely change the nature of radio communications in the band.”

The commission hired the 19-nation European Space Agency to test the effects on navigation signals of a LightSquared base station, and the results are similar to other tests conducted in the United States for the past six months. The commission concludes that LightSquared poses “a grave threat” to navigation users, especially for safety-critical applications in aviation.

LightSquared submitted its proposal for how it can best work with GPS to the FCC June 30. After months of saying GPS users should be able to live with LightSquared’s use of frequencies adjacent to those reserved for GPS, the company proposed to suspend use of half its licensed spectrum until the GPS issue could be sorted out.

The proposal, using language that LightSquared had not used previously, characterizes manufacturers of GPS equipment as having scant regard for the intelligent use of frequencies after years of being babied by free access to GPS satellites and the absence of any major licensed users of the spectrum next door.

The result, LightSquared said, is that too many GPS terminals are overly sensitive to signals coming from frequencies outside the GPS band.

“The [FCC] should not countenance the commercial GPS industry’s demand for squatter’s rights,” LightSquared said in its proposal. “Had GPS device manufacturers simply used filters — whose costs would have been as low as five [U.S.] cents per device,” the company said, “the entire problem could have been avoided.” GPS manufacturers, LightSquared said, have “colonized” a swath of spectrum for which they have no license.

“It is particularly shocking that this is the conduct of an industry that has never invested in a satellite, but rides for free” using the GPS constellation financed by U.S. taxpayers, LightSquared said.

For LightSquared, which said its current and previous owners have invested $4 billion in the project, the question now is whether the head of steam built by the GPS community is not too great to overwhelm even LightSquared’s agreement to start its service only in the lower half of its assigned spectrum, which poses less of a problem to GPS.

The FCC has asked for comments on the LightSquared proposal, with a deadline of July 30. Another two weeks will be given to those wishing to reply to the comments, after which the FCC will be asked to decide how LightSquared may or may not proceed.

The U.S. National Telecommunications and Information Administration (NTIA) was among the first to weigh in with a formal opinion to the FCC. On July 6, NTIA asked the FCC to order that further testing be done and that LightSquared’s commercial operating license be withheld until that testing is completed.

NTIA acted following an assessment of LightSquared’s GPS interference potential made by an engineering group affiliated with the National Executive Committee for Space-Based Positioning, Navigation and Timing. This group wants LightSquared to be denied access to frequency territory that the FCC already licensed to LightSquared, located between 1525 and 1559 megahertz.

GPS industry officials had suspected for weeks that LightSquared would move off its all-or-nothing demand and eventually propose using only the lower part of its authorized spectrum. That is what the company proposed June 30. It will limit its early operations to 1526-1536 megahertz, which it said is far enough from the GPS spectrum to avoid interference with 99 percent of all GPS terminals on the market.

Unfortunately for LightSquared, causing a problem for 1 percent of the GPS terminal population still means several million affected terminals, especially precision equipment for agriculture and construction.

LightSquared promised to begin deploying its network around urban areas, which would avoid some of the agricultural GPS terminals. The company further said it would help in the design of filters to be fitted onto the GPS terminals that suffer interference. The company said that, in addition, it will operate its system in this narrower frequency band at lower power to minimize interference.



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Peter B. de Selding was the Paris bureau chief for SpaceNews.