The Senate’s version of the National Defense Authorization Act contains language attempting to slow the rollout of Ligado Network’s use of the L-band spectrum, which defense officials say will harm GPS capabilities.

The bill language, revealed in a summary Thursday, “prohibits the use of [Department of Defense] funds to comply with the [Federal Communications Commission] Order on Ligado until the Secretary of Defense submits an estimate of the costs associated with the resulting GPS interference.”

It also directs the defense secretary to put the National Academies of Science and Engineering on contract for “an independent technical review of the order to provide additional technical evaluation to review Ligado’s and DOD’s approaches to testing,” something that has become a focal point for outside groups concerned about Ligado’s plan.

The legislation represents follow-through from Sen. Jim Inhofe, R-Okla., the Senate Armed Services Committee chairman who has been among the most vocal opponents of the Ligado approval. Both Inhofe and his Democratic counterpart, Sen. Jack Reed of Rhode Island, have raised concerns about Ligado’s potential impact on the military’s use of GPS.

In an April 20 vote, the FCC unanimously supported Ligado’s request to use the L-band spectrum, despite heavy opposition from the DoD and other government agencies, as well as commercial trade groups, which believe the Ligado plan will damage the usability of GPS. On May 22, the federal government formally requested the FCC reconsider its position, but analysts do not expect such a reversal.

Oversight of the FCC lays with the congressional Commerce committees, limiting what the Senate and House Armed Services committees can actually do to force the issue.

The next question is what form of this legislation, if any, appears in the House version of the NDAA. Like their Senate counterparts, House Armed Services Committee Chairman Adam Smith, D-Wash., and Rep. Mac Thornberry, R-Texas, have raised concerns over Ligado, with the two men claiming that the FCC did not fully take the Pentagon’s concerns into account before voting.

In addition to the Ligado-specific language, the Senate seeks to transfer the functions and responsibilities of electromagnetic spectrum operations currently with the commander of U.S. Strategic Command to the chairman of the Joint Chiefs of Staff. The summary of the language also says there will be additional responsibilities on spectrum issues for the vice chairman of the Joint Chiefs, but does not spell them out.

Aaron Mehta was deputy editor and senior Pentagon correspondent for Defense News, covering policy, strategy and acquisition at the highest levels of the Defense Department and its international partners.

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