Rendering of LightSquared's latest satellite.

The group also rejected a three-pronged proposal put forth by Reston, Va-based LightSquared, which it says would mitigate any interference the company's planned 4G networking system could cause to GPS receivers and applications across the United States and international regions.

“There is no single, simple solution that can eliminate interference for all classes of GPS receivers in the near term,” said Charles R. Trimble, chairman of the United States GPS Industry Council, in a statement released with the report. “GPS touches every aspect of our lives. It goes beyond the most widely known navigation applications such as car navigation and cell phones to hugely important applications such as agriculture, electric power grids, communications networks, infrastructure monitoring and construction.”  

Jeff Carlisle, executive vice president for regulatory affairs and public policy for LightSquared, and Trimble co-chaired the TWG,  which was formed to delve into GPS interference claims as a condition of a waiver by the Federal Communications Commission  that could enable LightSquared to build an "L-band terrestrial network" on frequencies that operate adjacent to GPS systems.

The report also indicated that there are no satisfactory fixes to the interference effects that can work across the broad range of GPS receiver designs and applications areas.

"All seven TWG sub‐teams reported that LightSquared’s proposed terrestrial broadband service will cause harmful interference to nearly all GPS receivers and devices tested," the report summary says.

"It did not matter which of LightSquared’s announced deployment phases were used; there were findings of harmful interference when LightSquared operations were tested using a 5 MHz or 10 MHz 4G LTE configuration with channels in the upper/higher portion of the 1525‐1559 MHz mobile‐satellite service/ancillary terrestrial component (MSS/ATC) (i.e., spectrum in the 1545.2‐1555.2 MHz range) alone, as well as when LightSquared operations were tested using a 4G LTE configuration with channels in the upper portion of the MSS/ATC range together with channels in the lower portion of the MSS/ATC range (i.e., spectrum in the 1526‐1536 MHz range)."

LightSquared rejected the GPS industry's contention that it should not be permitted to operate its L-band terrestrial network on its authorized frequencies.  "This choice would doom an innovative American start-up company that has devoted more than 10 years of effort and billions of dollars in reliance on explicit regulations and authorizations permitting it to proceed as planned with a vital new wireless network," LightSquared said.

Industry Impact and Next Steps

Mark Knight, owner of Foothills Contracting, a grading contractor located in Webster South Dakota, says a lot of construction companies are highly involved with GPS; his company has already sunk three quarters of a million dollars into GPS systems.

 “Critical pieces of the construction process would be shut down,” Knight says of the LightSquared network plans. “Let’s say that we have a concrete paving contractor right behind us doing the paving, and we happen to lose signal for 15 or 20 minutes. It would be devastating. If we lost signal for 4-5 hours it would shut down our whole process of grading graveling and paving. You’ve probably got a cost factor of $150,000 a day. "

LightSquared argues 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.

The FCC is expected to hold a comment period for 30 days, followed by a rebuttal period, before a final decision is rendered on LightSquared's plans. For its part, LightSquared said it would not proceed with any network plans until a solution is found and called on the GPS industry to help find a solution.

"It is unthinkable that a nation which recently completed a complex digital-television transition involving nearly every household in the U.S. will be stymied by a problem posed by approximately 200,000 GPS devices. But LightSquared cannot solve this problem on its own. It needs the cooperation of the GPS industry," the company said in a statement.

Added Chris Stern of technology PR firm Burson-Marsteller, which is representing LightSquared, "We've got to get the engineers talking to the engineers instead of lobbyists and lawyers shouting at each other about this.”