Commercial airlines are not the only ones concerned about the roll out of 5G in the C-band. The military voiced its misgivings before the spectrum auction was even held and has been testing to see if 5G might affect radar altimeters since at least last spring, according to Defense News. These tests, which may take months to complete, will add clarity to the issue of altimeter interference from 5G in the C-band.
“At the center of the controversy is whether the deployment of 5G networks…in the C-band will interfere with radar altimeters used by military, civilian and commercial aircraft and helicopters,” Defense News reported.
The news of possible military issues with C-band 5G seems to come out of the blue. However, the FAA and the Department of Transportation had concerns over interference to aviation technology back in December 2020, when they sent a memo to the FCC requesting a pause in the spectrum auction, Defense News reported. But instead of fighting the FCC C-band auction, the U.S. Department of Defense opted to develop interference mitigation. The auction, therefore, began as scheduled on December 8, 2020, and was completed on February 17, 2021.
In January 2021, before the auction was even over, the Defense Department was already focusing on “preventing interference to aviation instruments” from C-band 5G, according to Defense News. “The approach should be not on trying to slow down 5G metro deployment, but speeding up development and testing of mitigations that can serve as an interim gap until avionics manufacturers can harden their systems,” Alan Burke, the Pentagon’s chair for the interagency Aviation Cyber Initiative Task Force told Defense News in a January 7, 2021 interview.
Defense News reported that the Defense Department is working with its FAA counterparts on the 5G issue. A “Joint Interagency FiveG Radar Altimeter Interference,” or JI-FRAI, has been working since March of last year to develop “quick reaction tests” to determine the impact of 5G on avionics.
“It could take months for the Defense Department to come up with a plan to resolve any technical failures that occur as military pilots continue flying in areas where the 5G deployment is occurring,” Breaking Defense said. The findings of JI-FRAI are scheduled to come out in June.
By J. Sharpe Smith, Inside Towers Technology Editor