Verizon and AT&T agreed to a second delay of 5G in the C-Band spectrum, acquiescing to concerns raised by the airline industry about potential interference with radio altimeters on airplanes.

The operators previously agreed to postpone the 5G launch from 5 December 2021 until 5 January 2022, and to reduce transmission power levels at airports through 5 July 2022. In late December 2021, US Secretary of Transportation Pete Buttigieg wrote to the operators requesting a further delay. He also asked them to let the Federal Aviation Administration (FAA) coordinate the rollout of 5G near airports.

On 2 January, Verizon and AT&T responded to Buttigieg in a joint letter, denying his request. Late on 3 January, both companies pivoted and agreed to delay their 5G rollouts in the C-Band spectrum for an additional two weeks.

In their letter to Buttigieg, the operators stated 5G and aviation can safely coexist in the US, just as they do in France. The companies also pledged to adopt 5G mitigation strategies similar to those used in France.

AT&T and Verizon promised to implement “extensive exclusion zones around the runways at certain airports”, predicting this additional mitigation will “reduce C-band signal levels by at least 10 times on the runway or during the last mile of final approach and the first mile after takeoff”. The companies plan to keep these mitigations in place for up to six months while aircraft operators upgrade their altimeters in order to avoid interference.

In a separate letter dated 31 December 2021, Verizon and AT&T told the Federal Communications Commission (FCC) they believe the airline industry wants to “hold the C-Band hostage until the wireless industry agrees to cover the costs of upgrading any obsolete altimeters”.