LightSquared filed a long-awaited report on possible GPS interference by its planned cellular network to the FCC on Thursday, along with a formal proposal to use a different block of frequencies to prevent those problems.
In a press release announcing the filings, the carrier focused on its new plan and slammed the GPS industry as the cause of the interference.
"GPS device test results, which were also filed at the FCC today, show unequivocally that the interference is caused by the GPS manufacturers' decision over the last eight years to design products that depend on using spectrum assigned to other FCC licenses," LightSquared said.
The company said its alternative plan, in which it would initially stay out of the portion of its spectrum closest to the GPS band, would solve interference for 99.5 percent of GPS devices in the U.S., including all GPS-enabled cell phones.
LightSquared has been testing its planned LTE (Long Term Evolution) network for interference with GPS over the past few months. The U.S. Federal Communications Commission required the test report as a condition for letting LightSquared build a hybrid satellite and LTE network across the U.S.
LightSquared's business plan is to set up a hybrid satellite and LTE network that uses frequencies in the MSS (Mobile Satellite Service) band, which so far has been reserved for only satellite-based systems. The company plans to sell access to the networks at wholesale to partners including Best Buy and Leap Wireless, which in turn will offer services to consumers. Sprint Nextel also plans to partner with LightSquared, according to news reports. The resellers can choose to offer either or both of the services.
The FCC gave conditional approval to the project because LightSquared's satellite network would reach all of the U.S. population, including rural users. But because the LTE network would operate at a high transmission power in frequencies near to those used by GPS, the agency required LightSquared to gauge the extent of the interference problem and resolve it.
Thursday's report originally was due June 15, but the FCC extended the deadline to July 1. However, key results of the tests were publicized even before the report was originally due. They showed some GPS receivers for aviation, public safety, agriculture and personal navigation losing GPS capability at varying distances from LightSquared cell towers. The final report confirmed these findings.
The alternative plan would take LightSquared out of the band where the most severe interference was found during testing, but critics such as the Coalition to Save Our GPS have countered that little is known about the effect of operating in only the lower spectrum. Also, it's not clear what process the FCC will use to evaluate LightSquared's new plan. Critics and lawmakers have called for more testing of the proposed solution.
Stephen Lawson covers mobile, storage and networking technologies for The IDG News Service. Follow Stephen on Twitter at @sdlawsonmedia. Stephen's e-mail address is stephen_lawson@idg.com
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