Global Positioning System constellation. Credit: U.S. Air Force

WASHINGTON —The Pentagon has been leading an all-out campaign to get the Federal Communications Commission to reverse its April 20 decision to grant a spectrum license to Ligado to build a terrestrial wireless network.

The FCC order allows Ligado to use L-band spectrum that is adjacent to that used by the Global Positioning System. DoD argues that a terrestrial broadband network in that spectrum band will interfere with GPS signals.

Mike Griffin, undersecretary of defense for research and engineering, said on May 20 that DoD will be seeking help from Congress to get the FCC to reverse its decision.

If the Ligado license is allowed to stand, the 1575 megahertz L1 signal from GPS will be compromised, Griffin said during an online event hosted by the Washington Space Business Roundtable.

Griffin said the Pentagon understands that only Congress has the power to do anything in this case because the FCC is an independent agency that is overseen by Congress and not by the Trump administration.

“Congress can and, we hope, will take whatever action is necessary,” Griffin said.

It’s up to Congress to “continue to protect space communications bands for space communications,” he said. “That’s fundamentally what this is about.”

The issue has drawn the attention of congressional defense committees. The Senate Armed Services Committee held a hearing May 6 where Griffin and other senior DoD officials testified that they were blindsided by the FCC’s ruling. They claimed that the decision ignored the results of extensive tests that showed GPS signals would be drowned out by the noise from ground emitters in the adjacent band.

Following the SASC hearing, the House Armed Services Committee on May 7 sent a letter to FCC commissioners asking them to reconsider their approval of Ligado’s proposal. The HASC said in the letter it would hold a classified hearing to review DoD’s testing reports and discuss the results with the FCC.

Gen. John Raymond, chief of space operations of the U.S. Space Force, said DoD officials will brief the HASC on May 21 on the Ligado issue. “It’s a briefing, not a hearing,” Raymond said May 20 during a call with reporters.

An FCC spokesperson said the agency could not comment on the HASC briefing. According to sources, Ligado executives were not invited to brief the HASC.

Question of committee jurisdiction

While the armed services committees have made it clear where they stand on this issue, they do not have jurisdiction over the FCC.

The panel that oversees the FCC is the Senate Committee on Commerce, Science and Transportation’s subcommittee on communications, technology, innovation and the internet, led by Sen. John Thune (R-S.D.) and Sen. Brian Schatz (D-Hawaii).

The subcommittee sponsored the MOBILE NOW Act of 2018 which directed the FCC and the Commerce Department’s National Telecommunications and Information Administration to identify spectrum resources for next-generation wireless systems.

Thune and Schatz have been advocates of protecting commercial use of spectrum and of the FCC’s role overseeing the private sector’s use of spectrum. The NTIA is the agency that coordinates the federal government’s spectrum use.

Sen. Richard Blumenthal (D-Conn.), a member of the commerce committee said during the May 6 SASC hearing that a reversal of an FCC order “would be highly unusual.”

Griffin said DoD Chief Information Officer Dana Deasy is leading the effort to get the order overturned.

“As I said in testimony, this is a fairly simple issue from a technical point of view,” Griffin said at the WSBR forum. “GPS signals, like all signals from space, are very weak,” he said. “Signals are assigned to a space communications band that for decades has been protected from terrestrial emissions.”

When Ligado years ago was allowed to use the L-band spectrum only to transmit from space, “we had no problem,” Griffin said.

The FCC said Ligado’s terrestrial network will be low power and will include a buffer zone to protect GPS.

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...