Steps that must be taken to study, analyze, and recommend ways to mitigate any interference from the “commercial terrestrial operations” on Ligado’s frequencies—and estimate costs eligible for “reimbursement”—were set out in a House/Senate Conference Report on the National Defense Authorization Act. The act became law on January 1.
Congress has put the onus on the Department of Defense to arrange the GPS-interference study, and has constrained the department from entering into or renewing a contract “with an entity that engages in commercial terrestrial operations using the 1525-1559 megahertz band or the 1625.5-1660.5 megahertz band unless the Secretary has certified to the congressional defense committees that such operations do not cause harmful interference to a Global Positioning System device of the Department of Defense.”
Defining that set of frequencies targets the block of bandwidth where Ligado, of Reston, Virginia, is working to establish a 5G wireless communications network that would power Internet of Things functions. Objections to the venture have flowed from a powerful coalition of public-sector and private-sector skeptics since it was approved by the Federal Communications Commission in April 2020. Their concerns center on technical-experts’ reviews of the diligence of Ligado’s efforts to assure GPS users that its radiations won’t block the fainter signals from the GPS satellite array.
AOPA has always looked at this issue from a safety perspective and has advocated for a more convincing data set on the GPS-jamming question for almost a decade, dating to when Ligado’s predecessor, LightSquared, pursued the network plan until bankruptcy switched off the project in 2012.
And, as GPS has emerged as the navigational backbone of the NextGen air traffic system, we and other aviation organizations have continued to emphasize that certainty about GPS integrity is a critical element of flight safety.
AOPA members have made it clear that they support the focus on safety by ensuring the functionality of GPS: In January 2020, one of the year’s most well-read stories on AOPA Online reported on a planned GPS outage in the southeastern states during a military training operation. It was one of numerous reports on planned GPS outages.
Ligado Networks, which on October 23 announced acquiring $4 billion in “new capital” to develop its network, has dismissed the technical objections to its project, and noted in the capital announcement that the cash infusion allowed it “to fulfill the FCC’s vision for utilizing its L-band frequencies and support the mobile industry’s commitment to ready this spectrum for 5G.”
The language to protect GPS in the National Defense Authorization Act, advocated by Sen. James Inhofe (R-Okla.), chairman of the Senate Armed Services Committee, includes:
- A provision ordering the Secretary of Defense to “enter into an agreement with the National Academies of Sciences, Engineering, and Medicine” to perform an independent technical review of the FCC’s order authorizing the Ligado network.
- A requirement to review methods the FCC used to establish its order; assess “the potential for harmful interference to mobile satellite services, including commercial services and Global Positioning System services” of the (defense) department; analyze the practicality and effectiveness of proposed mitigation measures; and produce a set of recommendations.
- A mandate for the National Academies of Sciences, Engineering, and Medicine to issue a report on technical findings to the congressional committees 270 days after the date the agreement is forged.
- Linking the appropriation of Department of Defense funding associated with the FCC’s order to compliance with the GPS-protection conditions.
- Preparing an estimate of the “range of reimbursable costs” associated with any harmful interference “resulting from” the FCC’s order.