Ookla

In what might be considered an upset, T-Mobile beat Verizon and AT&T in a nationwide speed score. The 2017 US Market report by Ookla used 14 million tests across 3 million devices to judge cellular speeds in the first half of the year. T-Mobile came in first overall.

Ookla used Speedtest intelligence for its report, and determined that overall cellular speed increased by 19 percent year-on-year in the US, but the country still dropped from 42nd to 44th in a global ranking of cellular speeds.

T-Mobile specifically won the Speed Score test, which incorporates both download and upload speeds across all regions of the country. Verizon and AT&T were hurt in this test for a justifiable reason -- they have more rural coverage than T-Mobile, and the scores in those areas lowered their final results.

Verizon came in second in the Speed Score test, and was first in an "acceptable speed" test in the country's 100 most populated markets. The "Acceptable Speed Ratio" measures the percentage of a carrier's tests that at least reach the threshold of 5 megabytes per second download speed. Ookla determined that level as the spot where most customers could use their phones without noticing lag.

Sprint came in fourth in most tests, but the company showed a nice improvement in speeds over last year. In an emailed statement, a company representative said, "We find value in all of the various tests and they show similar results -- that Sprint's network continues to improve. Even more important, Sprint customers are satisfied with our network."

A T-Mobile representative noted that this is the 14th quarter in a row in which T-Mobile came in first and added, "That should tell you all you need to know about the current state of wireless networks in the US -- T-Mobile is thriving in the unlimited data era while both Verizon and AT&T struggle."

The Ookla test does note that Verizon and AT&T have an increased number of tests below the 5Mbps threshold since unlimited plans have become widely available. Ookla attributes the decrease to deprioritizing data for customers that use a lot of it, and to customers selecting cheaper plans at lower speeds.

Mike Haberman, VP of Verizon Wireless Network Operations, said, "These tests confirm that we have phenomenal coverage across the country, the largest LTE network -- roughly 750,000 square miles more coverage than T-Mobile -- and great speeds. While these crowd sourced tests don't show how reliable a network is, other scientific studies do -- and Verizon is the clear leader."

AT&T did not immediately respond to CNET's request for comment.