Sully Adds Voice To Lobby Against Potentially GPS-Jamming Cell Network


The lobby against the granting of radio spectrum adjacent to frequencies used by GPS to a startup wireless provider has enlisted Capt. Chesley Sullenberger to press its case. In April, the Federal Communications Commission, over objections from the Department of Defense and Department of Transportation, agreed to allow Ligado Networks to establish a new broadband wireless network on a thin slice of radio spectrum that is right next to the frequencies used by some of the most important providers of satellite navigation and aviation services. The fear, which detractors say the FCC has recognized, is that the much more powerful terrestrial cell emissions will overpower the minuscule bits of energy beamed by the satellites, effectively jamming them. 

Ligado tried to do the something similar eight years ago under the name LightSquared but failed to convince the FCC. In April, the commission ruled that Ligado had cleaned up the technology to the point where its cellphones and towers won’t create “harmful interference” for GPS receivers.

In a submission to the Space Based Positioning, Navigation and Timing Advisory Board, Sullenberger said the granting of the spectrum use to Ligado “constitutes a dereliction of duty on the FCC’s part.” Sullenberger said the decision imperils everything from drone operation to modern farming to ATMs, in addition to military and civilian aviation. Sullenberger said the particular strip of radio spectrum granted to Ligado was previously a “quiet zone” designed to buffer the delicate satellite signals from space from the billions of times more powerful terrestrial signals that Ligado will put out. The Ligado frequency is only 1 MHz away from that used by Iridium for its network of satellite phone transceivers.

Sullenberger said in his statement that shielding their equipment from the “loud neighbor” that suddenly moved into their neighborhood would mean significant cost and inconvenience. He said the Ligado signals will have the greatest potential to interfere with VFR-rated GPS equipment and those used by drones, including their geofencing capability that prevents them from entering areas where drones are not allowed, like military bases.

Meanwhile, Ligado leveraged the FCC approval into $100 million in new investment to “build 5G IoT networks that serve mission-critical industries like public safety and emergency response, commercial transportation, energy, and manufacturing.” CEO Doug Smith said that’s the first of many funding rounds it expects to attract to build its network. “The investments will create American jobs, expand innovation and directly enhance critical industries such as first responders, health care workers and supply chain personnel that depend on ubiquitous and ultra-reliable networks to protect and secure American lives,” he said in a press release.

There’s also some political intrigue surrounding the issue, including a call for a conflict of interest investigation into the role of Dennis Robertson, head of the FCC’s Technical Advisory Council. Robertson is also the head of Robertson and Associates, which did the pivotal interference testing on Ligado’s cell signals’ interference with GPS. Robertson said he welcomes the investigation but is upset that it’s happening. “This is the sort of thing that discourages people from supporting and serving the government,” he told

Russ Niles
Russ Niles is Editor-in-Chief of AVweb. He has been a pilot for 30 years and joined AVweb 22 years ago. He and his wife Marni live in southern British Columbia where they also operate a small winery.

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  1. Robertson said, “This is the sort of thing that discourages people from supporting and serving the government”. Hogwash. Robertson serves on the Technical Advisory Council to represent his company and leverage it for business opportunities. If he was truly interested in “serving” the government, he should have announced the potential for a conflict and recused himself from the investigation.

    The problem with this system is that, by the time we discover there is an interference issue, it will be too late. The towers will be built and the company will cry that taking them down will cost “American jobs”. LightSquared failed because the FCC did its job and determined there was a problem of interference. This time, money managed to overpower the FCC and go around it. I seriously doubt that the “new technology” has managed to eliminate potential interference. They just figured out that enough money will overpower good science. If the DOD and DOT are against this, we should listen to them. They are the ones that operate and understand the global GPS system.

  2. GPS has always been more susceptible to interference, spoofing, and outages. That’s why I don’t care. This is old news. Use at your own risk. Carry a map.

  3. Serving the government…public service. Phrases that are ridiculous. “Public servants” get paid for their work. At the national level quite well.

    Serving the public? Robertson gets paid for his work as head of the FCC’s technical advisory board I am sure. And he gets paid for his work as head of Robertson’s and Associate. This is the perfect combo as why so many people want to get into “serving the government” as Robertson so “sacrificially” has. What could possibly go wrong with this government service arrangement?

    Conflict of interest? Today, that is the aphrodisiac leading to “serving the government”. It appears to me Sully, common sense, safety, and integrity have no place in today’s “government service”.