India 4G availabilty
An employee of Bharti Airtel Limited runs after adjusting the screens of a promotional billboard during the launch of Airtel's 4G services in Kolkata on April 10, 2012.DIBYANGSHU SARKAR/AFP/Getty Images

India has managed to secure the 15th position in terms of global 4G availability ranking, thanks to Reliance Jio's unprecedented entry into the local 4G market in September last year, according to OpenSignal's latest State of LTE report. The big growth in India's LTE market, however, comes with a flip side in the form of lower average speeds, the new report has added.

Jio's far-reaching impact on India's 4G segment is "a rare instance" in which a newcomer single-handedly reshaped a mobile market in such a short period of time. Jio's nationwide launch of 4G services triggered a 4G revolution in India, attracting 100 million LTE subscribers in six months since its launch in September, and making the overall 4G services far more accessible in the Southeast Asian nation with an availability rating of 81.6 percent.

"Our testers on Jio's network were able to find a 4G signal 91.6% of the time, an exceptional availability measurement by any global standard," the OpenSignal report said. "In comparison, no other Indian operator scored higher than 60% in our availability tests."

According to the report, both Idea and Vodafone came second, with each of them averaging LTE availability metrics of 59 percent. Airtel, the country's largest telecom operator, was ranked in last place, accounting for only 54.7 percent of the LTE availability metrics.

The report, however, also said that while 4G LTE service is growing in more countries, the majority of the new networks in developing markets fail to match the capacity of their counterparts in developed markets.

India 4G availabilty
Despite growth in 4G availability, download speed still remains a concern in India.OpenSignal State of LTE report

"That trend is particularly apparent in Costa Rica and India, where average 4G speeds are only marginally faster than the average global 3G connection," the report said, adding that the average 4G download speed for all four national operators was found to be only 1.14 Mbps, which is well short of the 17.4 Mbps global average 4G download speed.

Overall, South Korea retained its top position by scoring the highest in 4G availability. The county also impressed by scoring the second highest in 4G speed in OpenSignal's test.

"South Korea and Japan are still the only two countries able to provide LTE connectivity more than 90% of the time in our tests," the report said, adding that almost all of the countries in the 75-nation analysis showed steady improvement in LTE reach.

"The mobile industry may now be turning its attention to 5G, but as OpenSignal's latest analysis of global LTE performance shows there is still plenty of activity surrounding 4G. As new LTE networks come online and old networks gain new life through LTE-Advanced upgrades, 4G signals are making their way into new niches across the globe and operators are pushing the boundaries of 4G speeds," the report said.

Check out our live 4G speed test comparison between Reliance Jio and Airtel