The companies said they will do so to allow federal aviation officials more time to study how such transmission might affect radio altimeters in aircraft.

The pair said in a statement: "We are committed to the rapid deployment of 5G and the safety of aviation. While we continue to believe the FCC's current rules provide for both, we will, without waiver of our legal rights associated with our substantial investments in these licenses, adopt these precautionary measures to allow for additional time for continued analysis."

Executives in the wireless industry don't expect the power reduction to "seriously impair" the operators' 5G operations in the spectrum band. Further, the operators continued to argue that their 5G transmissions in C-band spectrum do not pose a risk to air travel in the US, despite a report from some airlines showing a potential risk of interference to aircraft operations.