US greenfield operator LightSquared has announced a plan to switch spectrum bands in an effort to head-off concerns that its frequencies interfere with GPS systems. The announcement comes just two days after the wholesaler secured a last-minute extension to a deadline requiring it to submit a report on interference to the US Federal Communications Commission.

According to a press release issued by the company, LightSquared says it will now shift into a 10 MHz spectrum block that is lower on the spectrum band and “located further away from the GPS frequencies, greatly reducing the risk for interference.” Using the GPS industry test results, LightSquared said that this lower block of frequencies is largely free of interference issues, “with the exception of a limited number of high precision GPS receivers that are specifically designed to rely on LightSquared’s spectrum.” The wholesaler had originally set this spectrum aside for future use.

The company, which earlier this week announced a network share deal with Sprint,  says that this “comprehensive solution” will allow it to “proceed with its business plan, protect the public’s stake in GPS and lay the foundation for future co-existence of a variety of wireless broadband services and GPS.” As part of the plan, LightSquared has also entered into negotiations with satellite company Inmarsat, which controls the alternative block of spectrum to “accelerate the schedule for LightSquared to begin using the frequencies.”

Over the past few months, test results released by the GPS industry have indicated that at least one of LightSquared’s 10MHz spectrum blocks interfered with GPS receivers, sparking transport safety concerns, particularly among the aviation and public safety sectors. The FCC had originally granted the wholesaler the right to use satellite and terrestrial spectrum for its services provided that it didn’t cause any major interference with GPS devices. As part of this revised plan, LightSquared says it will “modify its FCC license to reduce the maximum authorised power of base station transmitters by over 50 per cent.” This, it says, will “limit Lightsquared to the power it was authorised to use in 2005, which will provide additional protection to GPS.”

The company says this new plan will give it enough spectrum to “serve its growing customer base for the next several years.”