Source: Sprint

In the wireless industry, it appears the overall value proposition is one of price versus network coverage area and quality. In the U.S. market, smaller carriers Sprint (NYSE:S) and T-Mobile (NASDAQ:TMUS) compete mostly on price while industry stalwarts Verizon (NYSE:VZ) and AT&T (NYSE:T) compete on coverage area. However, what constitutes good coverage is highly subjective, territorial-dependent, and hard to quantify on a national scale.

For those who follow the industry, RootMetrics' Mobile Network Performance Review is a chance to look past company spin to see what networks are improving, falling behind, or standing still on a national, statewide, and major metro scale. For its "2nd Half 2014" review, RootMetrics performed 5.7 million tests, drove 288,000 miles, and covered 100% of the population to determine the best carrier. The company tested the four company's networks on data, text, and call performance; followed that with network speed and reliability tests; then aggregated those scores to come up with overall performance.

RootMetrics' comprehensive national results confirmed Verizon's and AT&T's network dominance. In the six tests, Verizon and AT&T fell No. 1 and No. 2, respectively, in all but one category -- text performance --in which AT&T placed first and Verizon finished No. 3 behind Sprint. That was not the only good news for Sprint, as the survey shows it's working on its worst problem: horrible network coverage.

Sprint reclaims No. 3 from T-Mobile nationwide
In the overall performance category, Sprint battled back to reclaim the No. 3 title lost to T-Mobile in the first-half survey by attaining a 86.6 score versus T-Mobile's 84. Sprint has been working on building out its LTE network, and it appears to be paying off. In the areas of call, text, and network reliability, Sprint performed better than T-Mobile in this survey.

T-Mobile CEO John Legere doesn't care for Sprint's data network or marketing strategy. Source: John Legere.

However, T-Mobile had some positive takeaways as well from the survey. In the areas of network speed and data performance nationwide, T-Mobile performed better than Sprint. The data performance is particularly important due to the growing demand for the product and T-Mobile CEO John Legere's insistence that his company has a better data experience than Sprint.

T-Mobile has more major metro "wins," but Sprint does better outside of metro markets
Of course, individual circumstances will probably vary from the national rankings. After all, each market is highly fluid -- reflecting investment in that area more than national upgrades. T-Mobile actually had the most "wins" -- first place finishes in the six individual categories -- among the top 125 metro areas tested. By earning 201 wins, the company improved its wins by 19% from RootMetrics' first-half 2014 survey, mostly on the strength of improving its text performance in metro markets.

However, Sprint significantly improved its position from the first half to the second within the metro areas tested. By improving its call performance from 17 wins to 64 and its reliability index from three wins to 28, Sprint claimed a total of 135 metro wins, a 400% improvement from its first-half total. And when you move beyond the major metro markets, Sprint tends to do better statewide than T-Mobile, hence the better overall ranking while trailing in individual metro markets.

To be fair to Verizon and AT&T, Sprint and T-Mobile are still far behind when it comes to most network service metrics, but it appears both are catching up. It will take significant capital expenditures, spectrum, and buildouts to compete with the top two, but it appears Sprint made better headway in the second half of 2014 than did T-Mobile. For investors, it is good to see Sprint finally addressing its Achilles' heel.