Experts Call for Spectrum Allocation Reform, Pointing to C-Band Clash Between Airlines and 5G

WASHINGTON, March 20, 2023 — Although the wireless and aviation industries’ fight over mid-band spectrum has been largely resolved, regulators and experts from both industries agree that the allocation process should be updated in preparation for future disputes.

The challenge for regulators is to balance the “importance of more spectrum for the commercial industry to allow a critically important technology, 5G, to expand… against the equally important issue of, we can’t have airplanes falling out of the sky because their altimeters are being interfered with,” said Lawrence Strickling, former administrator at the NTIA, at an Information Technology & Innovation Foundation event on Monday.

The disagreement between the two industries peaked in January 2022, when the Federal Aviation Administration warned that the safety concerns surrounding major wireless carriers’ planned 5G rollout would lead to widespread flight delays and cancellations — causing an “economic calamity,” according to the leading airline industry association.

The airline industry’s concern was that 5G might interfere with radio altimeters, which provide critical elevation data for flight safety and navigation equipment, explained Jennifer Holder, director of aviation safety and regulatory affairs for Boeing, at the ITIF event.

“In the aviation industry, we don’t deal in ‘mights,’” Holder said. “You have to prove it’s safe.”

Wireless companies agreed to temporarily postpone deployment and work with aviation stakeholders to find a compromise. “We believe we have identified a path that will continue to enable aviation and 5G C-band wireless to safely co-exist,” Acting FAA Administrator Billy Nolen said in June.

Although that particular crisis was averted, many stakeholders agreed that the situation proved the need for an updated spectrum allocation process.

“Spectrum allocation works really, really well for the most part,” Strickling said. “But when you get into these really, really important issues that have severe consequences for different parties, it requires a little more coordination… at an interagency level to avoid the kind of controversy and disappointments that the altimeter controversy created.”

In addition to cooperation between multiple federal agencies, Strickling emphasized the importance of White House involvement with this type of challenge.

Mid-band spectrum remains a key part of innovation in the wireless industry, explained Tom Power, senior vice president and general counsel for wireless trade association CTIA. The C-band is sometimes nicknamed the “Goldilocks band” because it balances the advantages of the lower and higher bands to provide both range and speed, he said.

“It is really important for the nation in terms of the economy and productivity and jobs that we find opportunities, particularly in mid-band spectrum,” he added.

Panelists call for advance planning from both industry and government

Given the thoroughness of aviation standards processes, Holder emphasized the importance of the FAA anticipating emerging technologies rather than responding after problems arise.

However, she also called for updates to the Federal Communications Commission’s rulemaking and allocation procedures to allow more time for research and communication.

“Over the years, it does feel like we’ve had to play defense on spectrum auctions… It is incredibly challenging to evaluate whether or not you have a safety of flight issue in a 30 to 90 day time period,” Holder said.

Strickling agreed, saying that industry stakeholders should be given “as much advance notice as possible” about the potential allocations or reallocations of various spectrum bands.

Previous studies on interference have arrived at different results, Strickling added. Slowing down the auction process could allow more time for competing interests to come together in the design and execution of research.

But before changes to the allocation process are made, the FCC’s spectrum auction authority — which Congress failed to extend earlier in March — must be renewed, panelists agreed.

“This C-band issue has obviously been challenging, but it really is a small bump in the road compared to what we’re facing if we don’t restore spectrum auction authority,” Power said.