Two of 21st-century America’s favorite gadgets — the smartphone and the GPS device — are on a collision course, according to a report delivered Friday to the Federal Aviation Administration.

The report says deployment of a massive new network of towers and satellites to expand wireless communication may effectively shut down Global Positioning System devices that are at the core of a multibillion-dollar plan to revolutionize aviation. They also may affect some GPS units used by drivers, bicyclists and boaters.

The report puts the Obama administration in a Solomonesque position with two of its most cherished, ambitious and expensive initiatives. The president has promised to make Internet access available to all Americans, even as the administration has pushed airlines to invest billions to install GPS-based equipment.

The Federal Communications Commission in January issued a waiver to allow Reston-based LightSquared to develop a $14 billion broadband communications system adjacent to the bandwidth used for GPS transmissions.

LightSquared’s proposal for a network of 40,000 ground transmitters working with a seven-story orbiting satellite will dramatically increase the system’s reach and versatility, but the transmitters will overpower the GPS transmissions, according to a report by the Radio Technical Commission for Aeronautics.

“The impact of a LightSquared . . . deployment is expected to be complete loss of GPS receiver function,” the RTCA concluded in its executive summary.

Report under review

The RTCA, a nonprofit research group that represents 400 government, industry and academic organizations, came into play because aviation is in the midst of a multibillion-dollar transformation that relies entirely on the viability of GPS. It was asked to determine just how much LightSquared’s plans would invade the GPS bandwidth.

RTCA officials declined to take phone calls or to release the full report Friday. The FAA said it was reviewing the report but did not release it. That left LightSquared and other interested parties in the awkward position of commenting on something they had not actually seen in full.

“Though we’ve not seen the full report, the summary indicates the analysis shows there would be interference if we used the frequencies closest to GPS, but it also indicates that if we use the frequencies farthest away from GPS, we would not cause any interference,” said Jeff Carlisle, executive vice president of LightSquared.

He said tests showed that GPS performed better on airplanes than analysts had predicted.

“Like all spectrum holders, we have an obligation to operate properly within our band, and we take that responsibility very seriously,” Carlisle said. “A robust GPS system is a vital national resource that LightSquared will not jeopardize.”

The uncertainty comes at a critical time for the revolutionary national aviation system known as NextGen, an innovation that is intended to catapult flying from a reliance on World War II-era radar systems into a GPS-based system that will allow more direct routing, save billions a year in fuel, reduce carbon emissions and streamline air travel so that it can better accommodate growth projected for the next decade and beyond.

With cash-strapped airlines already taking an “after you, Alphonse” approach to equipping their fleets — wary that the FAA won’t have corresponding equipment and procedures in place on time — adding one more troublesome variable heightens the anxiety.

Former acting FAA administrator Bobby Sturgell, now a senior vice president with Rockwell Collins, said Friday that the LightSquared project should undergo additional testing and “should not be rushed.”

“We want to see the complete report,” Sturgell said. “However, the executive summary confirms what we believe, that LightSquared’s terrestrial-based system interferes with aviation GPS, which is a major public safety issue.”

In an earlier interview, Sturgell said the LightSquared plan is “a big concern not just to NextGen, but to the GPS community at large, and the military is very concerned about it, as well. This company has a conditional waiver, they’re marching toward a September deadline to start rolling out these towers and they want to have service by the end of the year.”

Possible interference

The departments of Homeland Security and Transportation also have expressed reservations about the plan.

When LightSquared began testing in Las Vegas last month to meet one condition of the FCC waiver, the FAA warned that GPS might be rendered “unreliable or unavailable” within about a 350-mile radius of the city.

Carlisle said data from the testing haven’t been compiled, but he said that certain GPS receivers capture signals from the LightSquared bandwidth.

“As soon as that was identified we were fairly certain that there were some receivers that were going to be susceptible [to interference],” he said. “The testing we’re going through is determining the type and scope of receivers that will be susceptible.”

The system operates on the L band, and 1559 megahertz is where LightSquared’s authorized bandwidth ends and the GPS band begins.

Once the testing in Las Vegas and other research is complete, a team that includes LightSquared representatives and GPS industry experts is to file a report with the FCC on June 15. After a period for public comment, Carlisle said he hopes the FCC will issue a confirmation that interference with GPS is not an issue, allowing his company to proceed.

LightSquared, backed by billionaire Philip Falcone and his Harbinger Capital Partners hedge fund, is muscling its way into a broadband market dominated by AT&T and Verizon Wireless. It plans to lease network space to companies such as Apple, Wal-Mart or others that might offer wireless devices under their own brands.

Reuters reported last Wednesday that LightSquared is close to a $2 billion-a-year network-sharing agreement with Sprint Nextel, which wants to rent space on the LightSquared network to launch its own high-speed wireless service.