From Ligado to Verizon to Dish, spectrum conflicts continue brewing

The FCC and other US government agencies are working feverishly to coordinate their spectrum agendas in the wake of a very public battle between the wireless industry and the airline industry over 5G. But it's clear the efforts haven't stopped spectrum disagreements.

The latest dustup involves ongoing concerns that Ligado Networks' planned wireless network will interfere with GPS signals. The FCC has issued multiple rulings in favor of Ligado. But a group of senators representing the US military are now trying to get the FCC to reverse its position on Ligado.

"We remain gravely concerned that the [FCC's] Ligado Order fails to adequately protect adjacent band operations – including those related to GPS and satellite communications – from harmful interference impacting countless military and commercial activities," wrote the leaders of the Senate Armed Services Committee in a new letter to FCC Chairwoman Jessica Rosenworcel.

"We urge you to set aside the Ligado Order and give proper consideration to the widely held concerns across the Executive Branch, within Congress, and from the private sector regarding the expected impact of the Ligado Order on national security and other systems," continued the group, which includes Sens. Jim Inhofe (R-Okla.) and Jack Reed (D-R.I.).

Figure 1: (Source: Inge Johnsson/Alamy Stock Photo)

Ligado has maintained that its network won't interfere with GPS but said it is willing to work with the Department of Defense to resolve concerns.

"After more than a decade of scientific review, the nation's spectrum experts at the FCC determined the concessions Ligado made and the conditions in the April 2020 FCC Order protect GPS. No concrete evidence to the contrary has been put forth by any private entity or government agency, including the Defense Department, despite repeated requests," the company wrote in a statement responding to the letter.

Ligado continued: "If there is an issue DOD is concerned about, the best way to resolve it is for the DOD and Ligado to work through those issues as soon as possible, as the FCC Order requires and as Congress has mandated. The science and facts support the FCC's unanimous, bipartisan decision to grant Ligado's spectrum, and if there are DOD GPS receivers operating in our licensed spectrum that need to be upgraded, Ligado is ready to do so."

Ligado owns around 40MHz of spectrum in the 1600MHz L-band, and the company is planning to switch on part of a 5G network in that spectrum in September in Virginia. Nokia is supplying some of the equipment for the network. Ligado eventually hopes to sell nationwide 5G services on a hybrid terrestrial/satellite network for private networking applications, including in the utility industry.

Concerns that the network will interfere with some GPS devices are not new. Ligado traces its corporate lineage to LightSquared – backed by billionaire investor Philip Falcone – which launched in 2010 with a plan to build a nationwide, wholesale LTE network that it would resell to other telecom operators or other companies. That plan fell apart after the FCC ruled that the proposed network would interfere with GPS signals.

LightSquared fell into bankruptcy, and Falcone exited the picture. But Ligado arose from LightSquared's ashes in 2015 with a plan to build a 5G network using that same L Band spectrum, but this time focusing on the Internet of Things (IoT).

As noted by Breaking Defense, the National Academy of Sciences, Engineering and Medicine is scheduled to review the possibility of Ligado's network affecting GPS. Its report on the topic is due next month.

5G crashing airplanes

One of the issues that may be dogging Ligado's ambitions are devices operating outside their FCC-specified spectrum bands. Indeed, that situation is at the heart of the ongoing clash between the wireless and airline industries over whether 5G in the C-band spectrum will affect some aircraft altimeters.

That issue almost brought some airline travel to a halt earlier this year before AT&T and Verizon agreed to dial down their networks around airports. The issue is critical to Verizon, which is working to deploy a broad nationwide 5G network in its C-band holdings, but less important to AT&T, which operates some 5G cell sites in the C-band spectrum. It's possible Verizon's network will be affected by interference concerns into next year.

"US airlines are continuing efforts to implement a permanent 5G solution, while ensuring the highest level of safety in the skies," wrote Hannah Walden, a representative of Airlines for America, a trade group representing the airline industry in the dispute. "As the US airline industry works to actively install the required aircraft modifications, we remain in close communication with the federal government, telecommunications companies, manufacturers and other stakeholders to achieve our shared goal of working to safely implement additional 5G service, so that the United States remains a world leader in both safety and technological innovation."

However, a recent report from AIN, a publication that tracks the airline industry, indicates there may be more disagreements bubbling beneath the surface of such statements. Specifically, the publication noted that aircraft radio altimeter manufacturers believe ongoing supply chain disruptions will make it "extremely difficult" to deliver the retrofits necessary to meet a July 23 deadline for altimeter updates set by the Federal Aviation Administration (FAA). Such kits may be required to ensure older airplanes won't be affected by 5G operations in the C-band spectrum near some airports.

"One airline industry and former FAA official speaking with AIN on the condition of anonymity complained of an undue influence telecom companies wield in Washington, referring to a 'revolving door' between the FCC and the industry," according to the publication. "Meanwhile, he said, the FAA 'dropped the ball' by not advocating for the aviation industry even while airlines sounded alarms over the issue for years."

Partly in response to the issue, the FCC has opened a proceeding into receiver standards that would potentially allow the agency to proactively address older electronics that operate outside the agency's prescribed spectrum bands.

Preventing 12GHz interference

It's undoubtedly these kinds of problems that the FCC is hoping to avoid as it wades into the ongoing debate over 5G in 12GHz. Indeed, potentially billions of dollars hang on what the FCC decides.

On one side of the 12GHz debate sit satellite companies including SpaceX's Starlink, fronted by billionaire Elon Musk. Those companies are currently using the 12GHz band in part for their burgeoning low-Earth orbit (LEO) satellite operations. Such services are in their infancy, but proponents believe they could grow to deliver Internet services to virtually every corner of the globe.

On the other side of the 12GHz debate sit Dish Network, RS Access and others, backed in part by billionaires like Charlie Ergen and Michael Dell. Some of those companies also use the 12GHz band for satellite-based services, but they're urging the FCC to also allow terrestrial 5G signals in at least a part of the band, potentially under some kind of spectrum-sharing setup. Starlink and others oppose the inclusion of 5G in the band.

The issue has blown up into a major policy fight, with Starlink enlisting thousands of its end users to flood the FCC's comment system in support of its position.

It's unclear which way the FCC is leaning on the issue. "A wide range of legal, technical, and policy experts from the FCC's Wireless Telecommunications Bureau, International Bureau, and Office of Engineering and Technology are engaged in this review and coordinating, as necessary, with other federal authorities in the process," Rosenworcel recently wrote in a letter to some members of Congress.

She declined to say what the FCC might do next but noted that the FCC, along with the NTIA and other government agencies, is working to implement the Spectrum Coordination Initiative announced earlier this year. That initiative is designed in part to "develop and implement a process for escalating any disputes for consideration by agency leadership." It is also supposed to ensure that various government agencies, from the Department of Defense to the FAA, are "committed to coordinating more of their spectrum activities."

But the process undoubtedly will take time. In the interim, it's likely that various policymakers, regulators, lawmakers, lobbyists and others will continue to work to bend US spectrum policy to their will, via whatever means necessary.

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— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano