Canada’s decision earlier this month to deny Ligado (formerly LightSquared) use of frequencies in the L-Band spectrum for its 5G network is fueling hopes in the U.S. that the Federal Communications Commission (FCC) may reverse its controversial 2020 approval to allow it in the U.S.
Leading aviation groups including the NBAA, Helicopter Association International, and the Aircraft Owners and Pilots Association have opposed the use of portions of the L-Band for wireless communication because of its potential for interference with global positioning system (GPS) and other global navigation satellite system (GNSS) technology. As recently as April 2023, these aviation groups, along with 90 other organizations, sent a letter to President Joe Biden urging revocation of the FCC’s “Ligado Order,” citing interference evidence from a 2022 study by the National Academies of Sciences, Engineering, and Medicine (NAS).
The Biden Administration has opposed the order via a petition for reconsideration issued by the Commerce Department’s National Telecommunications and Information Administration (NTIA). The opposition groups maintain that the order “is fundamentally flawed, incompatible with the FCC’s rules, and inadequate in protecting incumbent services from the harmful interference from Ligado’s proposed operations.” The groups note that the order also is opposed by the Department of Defense (DOD) and a bipartisan group of federal legislators.
Due to national security considerations alone, the groups maintain that the order should be stayed, noting that the NAS study showed that “the terrestrial network authorized by [the Ligado Order] will create unacceptable harmful interference for DoD missions.” The groups urged Biden to “work with the FCC to address the harm from Ligado’s proposed terrestrial network to critical GPS, satellite communications, and weather forecasting services by staying the order, addressing the previously unavailable information contained in the NAS report, and resolving the pending petitions for reconsideration.”
Reacting to the Canadian decision, Iridium’s Kara Leiben Azocar, v-p of regulatory, wrote FCC Secretary Marlene Dortch, restating concerns raised by Innovation, Science, and Economic Development (ISED) Canada in its denial—which was supported by that country's Department of National Defense, Transport Canada Civil Aviation, and the Canadian Coast Guard. Azocar wrote, “The well-supported objections from the federal government, stakeholders representing a broad cross-section of federal and commercial users of L-band satellite services, and now Canadian regulators convincingly demonstrate the unacceptable and detrimental risks of interference from ATC [ancillary terrestrial component] services authorized by the Ligado Order. The public interest requires that these facts be taken together to stay and reverse the Ligado Order.”
NAS’s 2022 study found that Ligado would likely trigger “harmful interference to mobile satellite service” provided by Iridium. The U.S. DOD is Iridium’s largest customer and employs high-precision GPS receivers, which would be the most vulnerable to L-band interference from the Ligado system. The committee that prepared the NAS report concluded that interference mitigation could be problematic due to test, certification, and time constraint issues, and overall costs. However, it found that Ligado would not impact most commercially available GPS systems.
In denying Ligado’s application in Canada, ISED noted concerns from aviation OEMs and groups, in particular the ATC’s impact on aircraft safety systems, such as helicopter terrain awareness warning systems (HTAWS) at altitudes below 300 feet agl, and said that multiple Ligado ATC base stations could have related aviation impacts in ways yet to be fully understood.
National Defense expressed similar concerns with regard to TAWS, while Nav Canada, the nation’s air traffic control organization, expressed concerns about precision operations that rely on aircraft GNSS receivers. Qualcomm raised objections based on the possible impact of an extended range of unwanted emissions on navigation data, especially those employed by emergency responders. And a variety of respondents raised concerns about the potential impact of out-of-band emissions on satellite communication.
ISED concluded, “Given the ongoing concerns with respect to interference to adjacent band services and the criticality of some of these services to Canadians, ISED is of the view that it would be premature to grant Ligado Canada an ATC authorization at this time.”
Ed Bolen, NBAA's president and CEO, said the collective evidence mandates that the FCC revoke the Ligado decision. “With numerous studies now reaffirming our industries’ concerns about dangerous interference to these vital systems from the Ligado network, it’s long past time for the FCC to do the right thing and rethink this ill-considered decision,” he said.
But concerns over Ligado could become moot if the company continues to experience financial difficulties. As LightSquared, the company filed for bankruptcy in 2012 and did not successfully emerge as a renamed and reorganized entity until 2015. Its current controlling owners are Centerbridge Partners, Fortress Investment Group, and J.P. Morgan Chase. However, not even the deep pockets of this ownership group insulated Ligado from a lawsuit filed earlier this year by Inmarsat, from which Ligado leases parts of the L-band spectrum. Inmarsat alleged Ligado was nearly $400 million in arrears on lease payments. That litigation appears to be on hold at the moment after an undisclosed settlement. However, Ligado’s lease provides that it pay Inmarsat an adjusted-for-inflation amount of $23 billion between now and 2107.