LightSquared’s three-part solution proposal focused on its decision to utilize lower frequencies provided by Inmarsat that are further away from the GPS spectrum. The network provider also produced its own testing results claiming that its solution resolves interference for approximately 99.5 percent of all commercial GPS devices- including all GPS-enabled cell phones. While the plan is the latest development in LightSquared’s plan to move forward, the company also used the proposal to lay some blame at the feet of GPS device manufacturers.

   “GPS device test results, which were also filed at the FCC today, show unequivocally that the interference is caused by the GPS device manufacturer’s decision over the last eight years to design products that depend on using spectrum assigned to other FCC licensees,” LightSquared said in the proposal. “The GPS device manufacturers, unlike relevant government agencies, have been largely uninterested in finding a win-win solution. This is a problem that the GPS industry could have avoided by equipping their devices over the last several years with filters that cost as little as five cents each.”

   Consumer market GPS manufacturer Garmin struck back at LightSquared, claiming that the company has no standing to shift responsibility back on manufacturers. Garmin engineers kicked off a debate on the issue in February by filing results of an interference test with the FCC.

“Before the Working Group’s testing began, LightSquared insisted that its transmission would not affect the GPS signal. Garmin’s own test results indicated otherwise. LightSquared then suggested that it had a filter on its transmitters that would solve any possible jamming issues. The Technical Working Group’s test results indicate that this filter will do little if anything to end LightSquared’s interference. In fact, there is no evidence that any effective filter solution currently exists for LightSquared transmitters or GPS receivers, and even if an effective one could be developed, it is years away from implementation,” Garmin said in a company statement.

   LightSquared said that despite the GPS industry’s claims, the FCC does not face a stark choice between GPS service and its 4G LTE network and that it cannot solve this problem without the cooperation of the GPS industry, however, its tone in the proposal suggests that cooperation is a long way off. “LightSquared believes cooperation is the least to expect from an industry that built a business by piggy-backing on the federal government’s GPS network without any investment in infrastructure or spectrum. A recent Brattle Group study showed that the commercial GPS industry’s ability to use the U.S. government’s GPS network amounts to an $18 billion federal subsidy.”