AT&T and Verizon are already on board, but the FAA is worried about smaller operators and spectrum holders
When it comes to rolling out 5G C-band services, the U.S. Federal Aviation Administration (FAA) wants the Federal Communications Commission (FCC) to mandate that smaller Communication Service Providers (CSPs) abide by the same restrictions that Verizon and AT&T agreed to voluntarily, earlier this year. Reuters claims the request was made in a letter between the two agencies dated Friday, October 21.
In January, the FAA issued 5G-related aviation warnings to pilots suggesting that some on-board aviation systems can be disrupted by C-band operations. The Notices to Airmen (NOTAMs) warned pilots that altimeters, automated landing and heads-up displays/enhanced flight vision systems for aircraft should be considered unreliable for use in specific geographic areas, as should the use of helicopter autopilot hover modes.
The FAA expressed concerned about the possibility of out-of-band interference with altimeter systems, which were not designed to deal with a changing RF environment or terrestrial 5G operations but are crucial to the ability to gauge how far an aircraft is above the ground at low altitudes, particularly during times of low visibility. Within days, the agency cleared about 45% of the U.S. commercial fleet for low-visibility landings at some airports.
In June, Verizon, AT&T and federal regulators said they’d come up with an agreement. In a statement, Verizon EVP Craig Silliman called the move “a path forward that will enable Verizon to make full use of our C-band spectrum for 5G around airports on an accelerated and defined schedule.”
The phased approach “requires operators of regional aircraft with radio altimeters most susceptible to interference to retrofit them with radio frequency filters by the end of 2022. This work has already begun and will continue on an expedited basis,” the agency said. Meanwhile, it says it has worked with AT&T and Verizon to identify airports where they can use their C-band spectrum with “the least risk of disrupting flight schedules.” The companies agreed to delay 5G C-band deployments near airports until July 2023, at which time air carriers are required to have completed avionics retrofits to mitigate possible 5G C-band spectrum interference.
In the letter referenced by Reuters, acting FAA administrator Billy Nolen warned that “aviation safety would be compromised if the U.S. government does not codify certain additional operating limits in the 5G C-band environment.” The letter was distributed to the National Telecommunications and Information Administration (NTIA) and to FCC chair Jessica Rosenworcel (the FCC oversees NTIA operations). None of the parties commented to Reuters about the contents of the letter.
The FAA letter states that the 5G mitigation zones around airports have been agreed to entirely voluntarily by AT&T and Verizon. Nolen noted that his agency has no regulatory authority to require the 19 other spectrum holders to adopt the same restrictions agreed to by AT&T and Verizon. He wants FCC and NTIA to codify the process.
