Washington (CNN) -- The government promises to keep your GPS safe from potential interference that could be caused by a new broadband wireless system now under review by federal regulators.
The system being developed by the company "LightSquared" would use satellites and relay transmitters on the ground to pass high speed Internet data. But an early design involved signals that could potentially block reception of those used for GPS -- the locating service used by consumers, aviation, agriculture, boaters and cellular 911 systems, among others.
Construction of the new system is on hold as federal regulators wait for the industry to eliminate the risk of interference with GPS receivers.
"We're not gonna do anything that creates problems for GPS safety and service," said FCC chairman Julius Genachowski at a briefing Tuesday with reporters. Congressional lawmakers, responding to concerns that began to be raised months ago by the GPS industry and grassroots groups, have demanded to know why the agency failed to realize the potential problem.
In a letter among colleagues this past May, several members of the U.S. House of Representatives warned, "These new transmission stations will emit signals that are one billion times more powerful than satellite GPS. These ground-based signals will interfere with GPS usage and could render the technology useless in many areas of the country."
The letter urged fellow lawmakers to ask the FCC to reconsider their decision granting tentative approval to the project.
Also in May, a bi-partisan group of U.S. senators expressed concern in a letter sent to the FCC chairman, asking that "the full Commission be involved in the process of making sure GPS is not compromised in any way, that the FCC require an objective demonstration of non-interference with GPS, and that the waiver for LightSquared be withdrawn until this demonstration is met."
LightSquared has since proposed a greater distance in frequency between its system and the signals used by GPS, minimizing the chance for interference.
But the FCC is not yet convinced the problem has been solved, even as the FCC chairman continued to defend LightSquared's idea to "both protect GPS and allow a new service to launch that will lead to billions of dollars in private investment, real job creation, and competition."
At a background briefing between FCC staff and reporters, the agency's technical experts and a government attorney explained the interference would not be LightSquared's fault, but rather, would be from the design of GPS receivers that makes them vulnerable to powerful nearby signals.
The GPS industry has disputed whether its receivers are the problem, since they were designed without a presumption a loud neighbor would move to frequencies nearby.
Nonetheless, two working groups are trying to cooperate in developing a plan to situate the LightSquared transmitters far enough away to not cause problems for GPS. And FCC staffers say the agency would frown on setting aside too much spectrum as a buffer, preventing a new use merely to insulate another service.
The agency could provide no timetable as to when continued testing, design modification, and FCC review of the project would be complete.