The 4G download speed of Reliance Jio has increased from 3.9 Mbps to 5.8 Mbps in the last six months – registering almost 50 percent increase in speed, according to OpenSignal.

This finding is part of the interim report from OpenSignal. The company will have a full report shortly.

Reliance Jio has stopped free data and voice services in April, 2017 as it started the migration of free customers to paid services with cost effective data plans. Reliance Jio has added nearly 130 million 4G subscribers in India ever since its launch in September 2016 – taking on Idea Cellular, Bharti Airtel and Vodafone in the Indian mobile Internet market.

After an uptick in February, Jio’s speeds leveled out at around 4.2 Mbps between the test periods ending in March and April, said Kevin Fitchard of OpenSignal in a blog post.

OpenSignal will release its second State of Mobile Networks report for India in a few weeks. The report will cover 4G speed offered by Airtel, Idea Cellular and Vodafone as well.

Earlier, Reliance Jio topped the 4G network availability chart in its India analysis, Jio ranked last in 4G speed as its millions of data-hungry customers competed for capacity on its LTE network. In April, most of Jio’s free offers ended, and customers started paying for their data services.

The main reason for this sudden influx of bandwidth could be that Jio has upgraded its 4G network, adding capacity.

It could be that customers started fleeing once the free data promotion ended, though a Bank of America Merrill Lynch survey found that most of Jio’s customers weren’t likely to abandon Jio.

Customers may be limiting their data use now that they actually have to pay for the megabytes and gigabytes they consume.