The U.S. is among the global leaders in 4G availability but lags dozens of other nations in download speeds, according to recent report.

The latest analysis of "The State of LTE" from OpenSignal included more than 50 billion measurements on more than 3.8 million devices worldwide between July and September — and found that 4G is reaching maturity in many more areas.

In the company's most recent test period, 50 of the 77 nations included in the report saw users connect to available 4G networks more than 70 percent of the time. In the previous report, issued six months earlier, just 33 countries hit that threshold.

The U.S., at nearly 87 percent, ranked 5th in the LTE availability metric, trailing only top-ranked South Korea, Japan, Norway and Hong Kong. South Koreans connected at a nearly 97 percent rate.

The increased focus on availability, however, appeared to come at the expense of network download speeds. Although the average 4G download climbed from 16.2 Mbps in the previous report to 16.6 Mbps, analysts said it was due to an influx of users in developing nations that offset speed declines among top nations.

Singapore led all nations in average download speed on LTE networks at 46.64 Mbps, followed in the top five by South Korea, Norway, Hungary and the Netherlands.

The U.S., meanwhile, trailed at no. 61 at 13.98 Mbps, just behind Kazakhstan, Chile, Morocco, Bolivia, Uruguay and Malaysia.

Although 4G speeds can vary based on many factors, OpenSignal analysts wrote that in general, "countries with the fastest speeds tend to be the ones that have built LTE-Advanced networks and have a large proportion of LTE-Advanced capable devices."

Analysts added that the apparent slowdown isn't necessarily bad news.

"The mobile industry — for the time being at least — appears to have shifted its focus from building powerful LTE networks to building far-reaching networks."

The report also noted that the stalled download speeds are likely only temporary.

"Once the next iterations of LTE-Advanced network and handset technologies become available, we'll likely see the 4G powerhouses kick off a new cycle of upgrades, pushing the top-most 4G speeds even higher," analysts wrote.