In a turf war between federal agencies that could prove deeply disruptive to travelers, the Federal Aviation Administration is threatening to ground planes if the Federal Communications Commission allows wireless carriers to begin operating in the C-band spectrum this week.
Ultimately, the dispute highlights a failure of our expert agencies to adequately shepherd what should have been a run-of-the-mill deployment process, thereby putting billions of dollars of investment and the future of robust wireless networks potentially in jeopardy.
At issue is whether 5G cellular communications could potentially interfere with older altimeter systems, a concern the FAA did not raise until the 11th hour. To be clear, the FCC did test 5G in the C-band for potential interference with aircraft operations and found no issues of concern. This should not be surprising, as C-band spectrum has been used around the world, with no reported aviation incidents. Moreover, radar has been used adjacent to the C-band for years, at power levels much greater than 5G.
For their part, the FCC did everything by the book, conducting years-long public proceedings on the C-band spectrum. The FAA and other interested parties from the airline industry had ample opportunity at any point during that process to conduct investigations and offer input, or ultimately to appeal the commission’s C-band decision.
It was not until this past November that the FAA suggested that some older altimeters might experience interference, although it was unable to tell the FCC how many of these older units were in operation. The FAA does not contend that it has discovered a new technical limitation that would merit blocking the thoroughly vetted bandwidth uses by cellular providers. Any problems with use of 5G in the C-band are mitigated by setting band noise limits, which the FCC has done.
Promoting safety and transparency is important, but it’s hard to avoid the conclusion here that the FAA is simply seeking an excuse to impede 5G rollout. It’s part of a long history of agencies seeking to wrest control of spectrum away from the FCC.
In 2019, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, and the U.S. Navy claimed the 24 GHz radio frequency band the FCC made available for mmWave 5G might interfere with weather satellites. Also in 2019, the Department of Transportation sought to challenge the FCC’s plan to re-allocate more than half the 5.9 GHz band to Wi-Fi and other unlicensed operations. The department cited the band’s use in Dedicated Short Range Communication (DSRC). Meanwhile, in 2020, the Department of Defense claimed an FCC-approved plan by Ligado Networks to use L-band spectrum for 5G services would interfere with Pentagon uses of the Global Positioning System (GPS).
Just as with the FAA today, no one ever produced compelling evidence in any of these prior interagency squabbles that responsible use of spectrum in those bands would create harmful interference. And in each case, the FCC publicly announced plans to allow access to a particular band well in advance, the proceedings moved on, and at the last moment, a federal agency intervened.
The FAA is entitled to ground planes if it thinks there is a legitimate reason to do so, but that’s not the real threat here. In the long term, the real threat arises from agencies attempting to undermine predictable and transparent rulemaking proceedings with untimely challenges. These sorts of turf wars have real costs, not just in dollars, but in sacrificing the legitimacy of what should be expert agencies to competently manage public resources.
Given the demand for spectrum, it would be counterproductive to distribute authority over its use to disparate federal agencies. Impeding rollout of 5G should require significantly more evidence than the FAA has produced thus far.
Kristian Stout is director of innovation policy with the International Center for Law & Economics (ICLE).