The Best Wireless Networks, State By State And City By City (Hint: Verizon Wins)

Verizon customers experience the fewest dropped calls, best call connections and fastest data speeds overall of any wireless mobile network in the United States, according to what may be the largest independent test of America's networks.

RootMetrics creates its RootScore Mobile Network Performance in the US report once every six months, checking for dropped calls, delivered texts, data speeds and other measures of mobile device performance. This time around, its study included more than 3.8 million tests; almost 232,000 miles driven; sampling in more than 6,500 indoor locations; and locations covering 100 percent of the country's population.

While the overall winner in today's report, written by Dave Andersen, is clear -- Verizon wins every category, generally by a good margin -- the details for your own state or metro area may surprise you. RootMetrics' report covers 125 metro areas, and you can search for yours at the company's website.

You can also find your state's performance.

Overall and for network reliability, the carriers landed in this order: Verizon, AT&T, Sprint, T-Mobile. In call performance, Sprint edged out AT&T for the No. 2 spot by a sliver of a margin, and in text performance, AT&T shared the win with Verizon. In network speed and data performance, the top two stayed the same, but T-Mobile passed Sprint for the No. 3 spot.

In addition to breaking down results by state and city, the report includes an overall evaluation of each carrier.

Verizon's been the overall winner in RootMetrics' network performance and reliability studies for five consecutive time periods, lending some truth to those "Can you hear me now?" ads. It also performs well across states and metro areas, handily leading in total numbers of RootScore Awards and providing the kind of consistent results that keep it on top of the heap. It may not always compete well based on price, but Verizon's claim to the best network in the country holds water, according to this report.

AT&T is a solid second choice, trailing Verizon in pretty much every category -- but not by much. In some metro areas, the giant performed better than others, but its consistency has been the key to its strong second-place finish in five consecutive tests, the report said. In general, its call and text reliability tend to outstrip its data performance, perhaps not surprising for the oldest and most-established network of the bunch.

At the state level, no other network increased the numbers of awards it took home more than AT&T. To put it in overall perspective: Verizon took home 272 of the state-level awards, AT&T had 110, Sprint had 36 and T-Mobile had 9. (On the bright side, T-Mobile customers, that's up from 0 in the first half of 2015.)

Sprint suffers from uneven performance. When it does well, it does very well indeed, largely in select metro areas. But in those areas where it performs poorly, it is easily surpassed by its competitors. (All the more reason to scrutinize those city-by-city rankings if you're looking for the best carrier locally.)

The carrier has made significant infrastructure improvements in a number of cities, leading to a boost in its overall scores, the report said. It jumped by 32 metro area RootScore Awards, the biggest increase for any carrier except Verizon, which improved by 85 awards won or shared. The other two carriers declined at the metro level.

"If Sprint can continue its LTE expansion efforts beyond metro areas, Sprint could close the gap with the other networks in multiple categories at the United States level," Andersen wrote. One place where Sprint scores consistently across metro areas: low numbers of dropped calls.

T-Mobile's relative national rankings stayed exactly the same throughout 2015, RootMetrics found. But the company's strength is inside cities, not out on the open road, so its national scores suffer as a result.

"If you primarily use your smartphone in a major metropolitan area, T-Mobile remains a strong choice," Anderson wrote. "Even though urban areas carry more weight in our results, it appears that T-Mobile currently lacks broad enough coverage to excel in our National or State RootScore studies."

The carrier may do better in 2016 tests, when voice-over-LTE will become the default call experience for RootMetrics testing of T-Mobile networks, he noted.