Verizon did it again. The nation’s largest consumer wireless carrier placed first in the latest network quality tests performed by RootMetrics in the last six months of 2017, sweeping all six categories (with one tie).
Verizon had the best network overall and also won for reliability, speed, data connections, and calling, RootMetrics said. For texting, Verizon tied for first place with AT&T and Sprint. AT&T was second in most categories nationally, with Sprint and T-Mobile bringing up the rear.
“Verizon’s performance in our national testing was once again outstanding and far stronger than that of any other carrier,” the testing firm, which measures network quality across the country, wrote in its semi-annual report. Verizon has dominated the company’s tests for nine straight reports, including the 2017 first half report in July, RootMetrics noted.
Get Data Sheet, Fortune’s technology newsletter.
After introducing unlimited data plans over the past two years, all of the carriers have been spending to improve their 4G LTE networks, some by adding more cellular transmitters and some by adding connections in new spectrum bands. The carriers are also preparing to deploy the next generation of even faster equipment, known as 5G.
Verizon took another victory lap over the results. “Since launching our unlimited data plan one year ago, our network performance continues to be consistently strong,” Nicola Palmer, chief network engineer and head of wireless networks, said in a statement. “These recent third party results confirm our overwhelming lead over other wireless providers in network performance and reliability.”
Sprint pointed to improvements in its performance and noted that other testing firms like Ookla have rated its network higher. “Despite being outspent by the competition in 2017, Sprint continued to improve its network and maintain its overall national rankings in the second half of the year,” the company said in a statement. Sprint has announced it will almost triple its spending on network infrastructure, after its merger talks with T-Mobile collapsed in November.
T-Mobile focused on other rankings where it has come out on top. “T-Mobile has closed the network gap, and the awards that matter – those from real customers on all networks – tell you all you need to know,” Neville Ray, chief technology officer, said in a statement. “T-Mobile customers are the most satisfied and are more likely to recommend us. They get an LTE signal more reliably and have the fastest LTE. Those are the reasons why millions of Verizon customers have flocked to T-Mobile.”
AT&T declined to comment.
RootMetrics’ methodology is different that several other firms, like Ookla and OpenSignal, which issue ratings based on crowdsourced speed tests performed by customers using free apps on their phones. T-Mobile topped OpenSignal’s most recent rankings.
RootMetrics conducts its tests with professionals driving around the country. Its surveyors conducted 4.6 million tests, driving almost 250,000 miles and also checking almost 8,200 indoor locations to compile the latest rankings.
RootMetrics also ranked the carriers in its six categories separately in each of 125 major metropolitan areas. Verizon won the most awards, at 601, followed by AT&T (t) with 365, T-Mobile (tmus) with 301 and Sprint (s) with 147. But for raw speed, T-Mobile actually had the most cities where download speeds averaged at least 20 megabits per second, with 97 out of 125 hitting that level. AT&T had 77, Verizon (vz) 71 and Sprint 16.