Award Winning Blog

Saturday, January 29, 2022

5G Bandwidth Expansion Triggers an Avoidable Aviation Safety Alarm

 Warring U.S. government agencies continue to debate whether expanded fifth generation wireless service will interfere with aviation altitude measurements, years after the parties should have resolved this mission critical issue. See, e.g., FAA Statements on 5G (Jan. 28, 2022);; Carr Statement on Biden Administration’s Failure of Leadership on 5G (Jan. 18, 2022);

In preparation for a 2019 global spectrum planning conference convened by the International Telecommunication Union, a specialized agency of the United Nations, the Federal Communications Commission, and even the President’s Executive Branch telecommunications advisory agency, summarily dismissed 5G altimeter interference concerns raised by the Federal Aviation Administration.  See Letter from Steve Dickson, Administrator, Federal Aviation Administration, to Adam Candeub, Deputy Assistant Secretary of Commerce for Communications and Information, Performing the Delegated Duties of the Assistant Secretary of Commerce for Communications and Information National Telecommunications and Information Policy, (Dec. 1, 2020);; John Hendel, How Washington flew into a 5G mess, POLITICO (Jan. 19, 2022);

Critical interference analysis should have continued, but it appears that the rejecting agencies expected the FAA to accept defeat and consider the matter closed.  Predictably, the FAA did not “speak now and forever hold your peace.”  It now has powerfully alarmed the court of public opinion with worst case scenarios of severe interference between 5G service and airline altimeter readings. See, e.g., Tom Wheeler, Did the FAA cry wolf on 5G?, TECHTANK, The Brookings Inst. (Jan. 21, 2022);; Stephen Gandel, How 5G Clashed With an Aviation Device Invented in the 1920s, THE NEW YORK TIMES (Jan. 19, 2022);; Andrew Ross Sorkin, Jason Karaian, Sarah Kessler, Stephen Gandel, Michael J. de la Merced, Lauren Hirsch and Ephrat Livni, Why Airlines Are Worried About 5G, THE NEW YORK TIMES (Jan. 20, 2022).

A serious matter, which could have been resolved through fair-minded technical assessment of interference potential and accommodation of cross cutting interests, now triggers FAA claims of calamity.   In the interim, the FCC auctioned off the newly reallocated 5G spectrum generating over $81 billion dollars for the U.S. treasury, (FCC Announces Winning Bidders in C-band Auction, (Feb. 24, 2021); with as much as $14.7 billion flowing to incumbent users of the C-Band satellite spectrum to defray their relocation costs.  See, FCC, Expanding Flexible Use of the 3.7 to 4.2 GHz Band, GN Docket No. 18-122, Report and Order and Order of Proposed Modification,  35 FCC Rcd. 2343 (2020); Caleb Henry, FCC sets December C-band auction, offers up to $14.7 billion for satellite operators, SPACE NEWS (Feb. 6, 2020); 

How Could This Happen?

For decades, the nations of the world have relied on an intergovernmental process designed to build trust and harmonize the use of radio spectrum and the orbits used by satellites. The ITU, has earned a reputation for lending its “good offices” to reach a global consensus, albeit one that can take years to complete.  Interference-free frequency allocations and uniform procedure for registering the orbital location of satellites enhance consumer welfare by promoting efficiency, shared access to global resources, and economies of scale. For example, a consensus on which frequencies to use for wireless services has made it possible for equipment manufacturers to offer single handsets useable in most places.

The ITU achieves consensus by adhering to a lengthy process requiring thorough study, ventilation of viewpoints, and trust building with an eye toward anticipating, avoiding, and resolving conflicts.  Because the process often reaches “consensus by exhaustion,” some national governments and commercial stakeholders have become increasingly dissatisfied with the pace and outcomes of conference deliberations.  The prospect for early market entry, global wireless leadership, and billions of dollars in auction proceeds encouraged the FCC and the Executive Branch to fast forward 5G frequency allocations with little concern about potential harm to the ITU planning process and inadequate assessment of altimeter interference potential, even after financing the departure of incumbent users.

Government Agency Squabbling

Compounding problems with the ITU process, the United States government failed to resolve all interagency disputes before the 2019 ITU World Radio Conference.  The parties had plenty of time to work through their disputes and reach a consensus on spectrum planning initiatives at the ITU.  Instead, the FAA persists, perhaps combining a heartfelt concern for aviation safety with the desire to remedy the sting of not having had its concerns adequately considered by other government agencies having more apparent expertise, clout, and the ability to generate billions for the national treasury.

Reaching closure on a single set of initiatives for ITU spectrum planning conferences will become more difficult for many nations as the nature and type of interested parties grows.  Representatives of ventures using new spectrum-intensive technologies, such as autonomous vehicles, finance, artificial intelligence, and the Internet of Things, will need more bandwidth.  While most applications require short distance transmissions and can tolerate multiple uses of the same frequencies, the massive increase in demand can result in congestion and in turn demands for exclusive assignments to foreclose even the possibility of interference. 

FCC did anticipate the need to separate commercial 5G services from nearby incumbent altitude monitoring by aircraft.  Despite an FCC-mandated guard band of 220 Megahertz, [1] separating the two types of services the FAA vigorously asserted that the potential for harmful interference would persist, particularly during critical aircraft takeoffs and landings at airports (see Robert D. Atkinson, C-Band Spectrum Rollout for 5G and Aviation Altimeters, ITIF INNOVATION FILES (Nov. 9, 2021);

The FCC and FAA should recognize that they have limited time available to avert greater harm to the national interest in both access to the latest innovations in wireless broadband and aviation safety. Had the FCC worked with the FAA to assess the actual potential for interference, despite ample separation of frequencies used, wireless consumers would already have access to a sizeable block of spectrum ideal for ultrawideband service.


[1]              “By licensing only up to 3.98 GHz as flexible-use spectrum, we are providing a 220-megahertz guard band between new services in the lower C-band and radio altimeters and Wireless Avionics Intra-Communications services operating in the 4.2-4.4 GHz band. This is double the minimum guard band requirement discussed in initial comments by Boeing and ASRC.” Expanding Flexible Use of the 3.7 to 4.2 GHz Band, Report and Order, at Para. 391.