WASHINGTON — The chief of staff of the U.S. Air Force Gen. David Goldfein said he is “very concerned” that the Federal Communications Commission approved Ligado’s terrestrial 5G network despite warnings from the Pentagon that the system will cause disruptions to the Global Positioning System.

The FCC on April 20 gave the go-ahead for Ligado Networks to use electromagnetic spectrum in the L-band adjacent to the spectrum used by the GPS constellation. This creates a significant risk of interference, Goldfein said April 22 during a call with reporters. Using an analogy to illustrate his point, Goldfein said GPS users could be put in a position equivalent to someone trying to have a conversation while music is blasted at full volume in the next room.

As chief of the Air Force, Goldfein does not have direct control over GPS satellites but he is responsible for training and equipping airmen who support U.S. Space Command. The command provides GPS-based services used by the U.S. military and by the global civilian economy.

Goldfein said he has discussed the issue with Gen. John Raymond, the Chief of Space Operations and commander of U.S. Space Command.

“We are both very concerned about this,” said Goldfein.

GPS signals, he said, have to be “pristine.” If the Ligado network moves forward, he and Raymond will be “looking at different mitigation steps.”

Goldfein noted that any future actions to address interference with GPS will have to be approved by the Defense Department, the Joint Chiefs of Staff and the military’s unified combatant commands.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...