Today at its Consumer Electronics Show (CES) presentation T-Mobile laid down the gauntlet for other mobile providers, promising to pay customers’ early termination fees if they trade-in their devices.

Even paying $650 for a customer to switch won’t be enough, though, if T-Mobile’s network isn’t up to the standard of what customers are used to. So, along with the termination fee announcement T-Mobile CEO John Legere announced what has become somewhat of a cliche in the mobile industry: that T-Mobile now believes it has the fastest 4G speeds of the top four U.S. mobile providers.

T-Mobile is backing up this statement through an analysis of user data collected from the Ookla Speedtest mobile app. The carrier claims that it has the highest average 4G LTE network speeds in the U.S., with an average of 17.8 Mbps last month. According to T-Mobile, AT&T’s average in December is the next fastest at 14.7 Mbps, then Verizon at 14.3 Mbps. Sprint follows as a distant fourth with average speeds of only 7.9 Mbps last month.

The image at the top of the article depicts Speedtest averages from January 8, the day of T-Mobile’s press conference.

“Finally we agree with AT&T on something: faster is better,” said Legere. “I warned the competition this day would come, and millions of speed tests from real people using their own phones prove it: T-Mobile’s nationwide 4G LTE network is the fastest network in the nation – bar none.”

Legere claimed that T-Mobile will be sending a cease & desist letter to AT&T, asking them to alter their marketing materials that claim the AT&T network is fastest.

Whether or not T-Mobile can truly be called the fastest mobile provider in the U.S., the company certainly does not have the breadth of coverage that AT&T has throughout the U.S., especially in smaller communities. To move up from fourth place, T-Mobile will need more spectrum deals like the one they struck with Verizon last week.