Pentagon leaders are increasingly worried that the satellite signals they need for operations will become a target for adversaries during future conflicts. But Maj. Gen. Robert Castellvi, commanding general of the 1st Marine Division, said March 2 that the Navy’s narrowband communications satellites were able to withstand significant interference during a December exercise.

Marines Corps leaders asked the Army’s Threat Systems Management Office to intentionally jam parts of the spectrum that the Navy’s Mobile User Objective System operates in for the Steel Knight 20 exercise in California.

MUOS, a constellation of five on-orbit satellites built by Lockheed Martin, operates over a span of about 20 MHz. Marines learned that the signal could survive jamming of up to about 50 percent of that threshold. That’s a significant amount, officials said, because jamming a greater portion of the spectrum more would require more power and, in turn, compromise an enemy’s position.

Officials later added that the exercise included a localized attack on a single radio intended to disrupt a single unit.

“This thing has been a game changer,” Castellvi said of MUOS, speaking at the annual West 2020 conference in San Diego. “It has bridged the digital divide gap we have between our higher headquarters, that require high bandwidth systems into the battalion, and below command posts that are dependent on very narrowband systems … It fared remarkably well.”

In addition, a new firmware upgrade to software defined radios that use the MUOS waveform provides further layer of protection, he said.

During the same exercise, Marines also focused on reducing the electronic footprint of their command posts to avoid giving away their location.

“It was amazing to see how low they can bring our signature down," he said.

Essentially, operators were emitting a signature that "the enemy would have seen equivalent to a single PRC-117G. We’re really testing the network in order to simulate the full range of friction that we would anticipate in a near peer conflict.”

Castellvi also pointed to using wireless internet at the secret level in combat operations center. This technology can reduce the time it takes to build and take down command posts.

The move “provided freedom and versatility unseen in any COC,” he said. “We have to be able to move, we have to be able to be survivable, we have to be more lethal. And that means a setup and takedowns have to be faster and wireless is a way to get you there.”

Mike Gruss served as the editor-in-chief of Sightline Media Group's stable of news outlets, which includes Army Times, Air Force Times, C4ISRNET, Defense News, Federal Times, Marine Corps, Military Times and Navy Times.

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