The attempts of LightSquared to build a national wireless broadband Internet service may be drawing to an end. Federal regulators' tests have shown the proposed LightSquared service interferes with the space-based GPS navigation signals which the military, commercial interests, and consumers rely upon, said the Federal Communication Commission yesterday.

Last year, concerns over possible interference with GPS signals, which uses a mixture of space- and ground-based transmitters, had forced further investigation and tests of LightSquared's proposed system, which uses a mixture of space- and ground-based transmitters and receivers. And while LightSquared claimed to have solved the GPS interference issue, the National Telecommunications and Information Administration sent a letter to FCC Chairman Julius Genachowski yesterday, saying:

Based on NTIA's independent evaluation...we conclude that LightSquared's proposed mobile broadband network will impact GPS services and that there is no practical way to mitigate the potential interference at this time.

In a press release, LightSquared said the company "profoundly disagrees" with NTIA's letter to the FCC, saying the agency "relied on the flawed conclusion" of the tests." The company "remains committed to finding a resolution" to the situation, saying:

There is no question that an America where both the GPS industry and LightSquared's network can co-exist is a stronger one for any administration that believes in competitive markets and job growth.

The FCC has not yet ruled that it will officially remove its waiver, which permits LightSquared to continue using its assigned frequencies. However, FCC spokesperson Tammy Sun said in a press release yesterday that the Commission is indeed proposing to revoke that waiver as well as "suspend indefinitely" LightSquared's authority to use that part of the radio spectrum that interferes with the Global Position System.

The FCC will reportedly issue today a request for public comment on the matter before it makes its final ruling on the LightSquared matter.

Statement on LightSquared [FCC]
Letter to FCC regarding LightSquare (PDF) [NTIA]
LightSquared Remains Committed to Finding a Solution [press release]
F.C.C. Bars the Use of Airwaves for a Broadband Plan [NY Times]