For now, LightSquared has dropped plans to use an upper portion of the spectrum band where the network could affect millions of consumer, aviation and other GPS devices. But it still wants to use a lower set of frequencies where its network would affect precision GPS. That technology is used mostly in agriculture, construction and surveying, according to LightSquared. The new technology would solve all or nearly all of the problems in that band, Neal said.

The federal government probably has tens of thousands of precision GPS receivers, most of them used in surveying by agencies such as the Army Corps of Engineers, though there may be military uses as well, Neal said.

The Coalition to Save Our GPS, an industry group that fiercely opposes LightSquared's plan, estimates there are between 750,000 and 1 million precision GPS devices in use by government and the private sector.

Earlier on Wednesday, the group slammed LightSquared's claim that it has a way to stop interference with precision GPS.

"LightSquared has, as usual, oversimplified and greatly overstated the significance of the claims of a single vendor to have 'solved' the interference issue," the group said in a statement. No one product can solve interference for the wide range of applications of precision GPS, which include aviation and life-safety operations, it said.