The U.S. Federal Aviation Administration (FAA) updated information Thursday, maintaining that U.S. 5G deployment will require the FAA to impose flight restrictions on flight operations using certain types of safety equipment that will perform in proximity to the 5G networks. AT&T and Verizon agreed to delay the use of C-Band spectrum until Jan. 19, a move that was endorsed by the White House. This extension would give the FAA more time to study and evaluate how to minimize the disruption to radar altimeters, while preparing airline companies for any changes.
The telecom companies, which won access to almost all the C-Band spectrum in an $80-billion auction, had earlier agreed to adopt 5G deployment with similar precautions as that of France.
The crux of the issue lies in the fact that radar altimeters, an important piece of safety equipment used in aircraft, use frequencies close to C-band. 5G services use C-band radio spectrum frequencies between 3.7 and 4.2 GHz that may prove hazardous to flight safety. Altimeters assess the airplane’s height above the ground and inform other safety sensors within the craft like collision-avoidance systems and navigation instruments.
As the situation currently stands, the proposed 5G deployment would result in modifying flight schedules and altering other aspects of the aviation network. The FAA is working towards mitigating these disruptions as they investigate the precautionary measures needed to move forward.
Telecom companies have also agreed on positioning the related antennas away from the airports where the interference would be greatest, while the FAA tests out how the radar altimeters work in a 5G C-band environment.
When altimeters are discovered to work without interference, the corresponding restrictions on aircraft operations will be removed. This process will go on until more altimeters are certified safe, retrofitted or replaced.
On Friday, the FAA released a list (pdf) of 50 airports that will have 5G buffer zones like Austin-Bergstrom Intl, Los Angeles Intl, Fort Lauderdale/Hollywood Intl, San Francisco Intl, and Chicago O’Hare Intl. These zones are expected to reduce risks when the wireless companies turn on their 5G services.
Many other airports are not affected by the rollout as they are not located in the same region where 5G is being implemented and some do not have the ability to allow low-visibility landings, according to the FAA.
AT&T and Verizon will adjust their operations like turning off transmitters near sensitive airports for a period of six months to minimize risk and avoid interfering with safety systems. However, it remains to be seen how the 5G networks will coexist safely with flight traffic systems in the coming days.