In July, AT&T and Verizon were able to begin using their C-band spectrum holdings to support 5G service at some U.S. airports. Opensignal took a look at how that impacted the providers’ 5G speeds. The answer: The providers saw significantly faster 5G speeds.

Shortly after AT&T and Verizon launched 5G service in the C-band in late 2021, the FAA expressed concern that those services interfered with altimeter equipment. The providers initially agreed not to use their C-band spectrum around airports for a month or two but subsequently agreed to the halt until July 2022. Later yet, the providers agreed to operate at reduced power levels.

That agreement between the providers and the airports called for the power level restrictions to lift beginning in July of this year at certain airports, while full-power operation at other airports would be delayed until as late as January 1, 2023.

To gauge the impact of the lifting of the restrictions at certain airports, Opensignal compared before and after time periods at 20 airports where restrictions has been lifted. A 90-day period starting April 1 was compared with a 90-day period beginning August 1.

Between those two time periods, AT&T’s 5G download speed increased 79.6% (from 70.7 Mbps to 126.9 Mbps) and Verizon’s increased 62.1% (from 81.6 Mbps to 132.2 Mbps). T-Mobile still was tops, but its increase between the two time periods – 172.8 Mbps to 174.5 Mbps – was not statistically significant.

Opensignal also measured download speed. At the end of the same periods, AT&T’s score increased 30.4% (39.2 Mbps to 51.1 Mbps) and Verizon’s 22.1% (41.5 Mbps to 50.7 Mbps). T-Mobile again stayed on top, but had a significantly smaller increase of 5.7% (94.6 Mbps to 100.0 Mbps).

“Our users on AT&T and Verizon enjoy stunning boosts in their average 5G download speeds after August 1, 2023 — compared to the period before July 1, 2023 — of 79.6% and 62.1%, respectively,” Opensignal author Robert Wyrzykowski wrote in a blog post. “Both surpass the 100Mbps milestone around the airport areas and are in a statistical tie, with scores of 126.9-132.2Mbps.”