NextNav Encouraged by U.S. Moves on Finding Alternatives to GPS
NextNav sees signs that the U.S. is moving to allow alternatives to GPS for positioning, navigation and timing (PNT), said Ed Mortimer, its vice president-government affairs, during a Broadband Breakfast webinar Wednesday. The U.S. was once the leader in GPS but has “fallen behind” countries like China and Russia, which already have alternatives available for PNT, he said.
Sign up for a free preview to unlock the rest of this article
Communications Daily is required reading for senior executives at top telecom corporations, law firms, lobbying organizations, associations and government agencies (including the FCC). Join them today!
GPS has been around since the 1970s and in civilian use for PNT since 2000, following an order by President Bill Clinton, Mortimer noted. PNT has since become critical to the electric grid, transportation networks and the financial industry, he said. NextNav was formed in 2008 to offer “a resilient, layered approach to providing PNT capability nationwide.” The company's proposal to use the lower 900 MHz spectrum it owns for PNT has been controversial, but it was one of the alternatives the FCC considered in a recent notice of inquiry (see 2505140017).
GPS is “a wonderful tool” but also “a single point of failure,” Mortimer said. “More and more adversaries [are] willing to disrupt or interfere with GPS.” He cited the International Air Transport Association's report that in the past year, there was a 175% increase in GPS jamming and a 500% increase in spoofing. “This has become a real problem for many industries. The time to act is now. Delay is not an option.”
Tanner Cheek, vice president-sales at French electronics giant Safran, said that in a sense, PNT is equivalent to aircraft's use of radio navigation, which started in World War II. “It’s really important [for] all of our customers, defense industry and consumers, that their products are in sync … and talking the same language.”
Cheek said many alternatives should be allowed to flourish. “There’s not going to be a silver bullet when it comes to PNT.” The U.S. needs “a system-of-systems-based approach,” he added.
Rohit Braggs, Iridium's vice president-PNT, said numerous PNT alternatives to GPS have emerged, and low earth orbit (LEO) satellites offer one of the best. GPS constellations are in orbit 25 times further away than LEO constellations, which means fewer satellites are needed for global coverage, but it causes other problems, he said.
Because the GPS constellations are so “high up in altitude … their signal is extremely weak when it’s received by receivers on earth,” Braggs said. “That’s one of the key root causes of why it can be jammed so easily.” Iridium has 66 satellites that cover the earth, and because they’re in lower orbit than GPS satellites, they're more resistant to jamming, he said.
Cheek agreed, saying GPS signals are so weak that a college engineering student could build a jammer that would take out signals over a limited area. GPS also doesn’t work well in urban areas, where the signals can’t get through, he said, adding that once you lose the signal, you lose PNT.
PNT alternatives are also important to first responders trying to locate emergency callers indoors, where GPS signals are often lost, Mortimer said, adding that using drones safely in a highly congested environment requires those alternatives as well. Jamming or spoofing a ground-based signal is 100,000 times harder than doing so to a GPS signal, he said.
Braggs likewise said LEO-based PNT provides a signal that’s 1,000 times more powerful than GPS and works indoors, where GPS signals often don’t penetrate.