Progress On A Technical Solution For Aviation Safety And 5G In Time For Christmas

The plan was for Verizon and AT&T to rollout 5G in the C-band on December 5, in time for the holiday broadband binging period. But the Federal Aviation Administration (FAA) issued a cryptic advisory on November 2 saying that while there was no evidence of interference, pilots should start watching their altimeters for odd readings. While these same pilots fly into more than 40 countries with some 175 5G networks in operation and report no problems with 5G, the FAA effectively deemed 5G as a threat to aviation safety. Mobile operators paused their rollout for 30 days and sought to reconcile the issue.

The Federal Communications Commission (FCC) undertook a two-year process of technical evaluation to develop the rules for the C-band, working closely with stakeholders from mobile, satellite, aviation, safety, federal regulatory, and other domains. In addition to regulations on power levels, interference, and other requirements, the FCC required a 200 MHz guard band between proposed 5G operations at 3.7-3.98 MHz guard band to shield transmissions from altimeters which operate at 4-0-4.2 MHz, twice what aviation industry requested (and which exacts an enormous social cost of funds which could otherwise go to the Treasury). Moreover, the FCC defined a phased rollout, first at 3.7 MHz to allow additional testing and only then at 3.8 MHz, effectively a 400 MHz guard band for the rollout. As such, it was entirely defendable in March 2020 that the FCC declared that there was no safety risk for altimeters from 5G operations.

The FAA knew about 5G for years but avoided making altimeter safety requirements for fear of upsetting its captive aviation trade associations which wanted to avoid the burden and cost of new equipment. The altimeter industry itself opted not to professionalize by developing international technical standards. It appeared that the FAA pressure was a means to shakedown mobile operators in the hopes for a payout to upgrade obsolete altimeters sitting in aging planes and helicopters.

Mobile operators drive the solution

Before Thanksgiving, AT&T and Verizon announced extensive voluntary, precautionary mitigation measures to assuage the FAA’s concerns in the and a commitment to launch January 5, 2022. The FAA said, “This is an important and encouraging step…The FAA believes that aviation and 5G C-band wireless service can safely co-exist.”  The operators proposed a series of mitigations for 6 months which go above beyond what any nation requires of its 5G providers and amounts to the world’s most protective environment for altimeters in developed countries. The mitigation includes

1.      Creation of a nationwide skyward power limit to restrict the amount of energy directed toward aircraft in flight

2.      Additional power restrictions around airport runways, taxiways, and gates that will limit energy directed towards altimeters during take-off, landing, and on the ground operation.

3.      Additional power restrictions at helipads to limit 5G emissions during near helicopter landings and other maneuvers.

Thus the mobile industry will drive additional real-world data to optimize transmissions and coexistence. Such a study should have been forthcoming from the FAA and the aviation industry, but not only did they submit bogus test results to the FCC, they refused to make the data public for scientific review.

Some Christmas spirit and cooperation

On December 22, CTIA – the wireless industry association, the Aerospace Industries Association, and Airlines for America announced an “ongoing collaboration to find a data-driven solution and deploy 5G while preserving aviation safety. The best technical experts from across both industries will be working collectively to identify a path forward, in coordination with the FAA and FCC.”

Congress and President Biden just concluded the bipartisan infrastructure bill with a $65 billion push for broadband. A White House fact sheet asserts, “Broadband internet is necessary for Americans to do their jobs and increasingly important for small business owners all across America.”  Indeed, national security leaders including 4-start generals urged the White House to resolve the issue, lest the US fall of behind China in 5G network rollout and service development.

Mobile operators, which spent tens of billions to buy spectrum and plan billions more to build networks, should be able to exercise their license rights. Companies make these investments on the premise of a stable regulatory environment. When it became clear that aviation interests would not move, mobile operators proposed a solution. Yesterday’s announcement is a promising step forward toward a final resolution that the aviation industry will accept. Investors should have the confidence that mobile operators will protect their assets from regulatory abuse. Maybe the aviation parties will find some Christmas spirit and cooperate further.