The survey said Jio's pricing scheme "forced incumbent telecom firms" to cut voice call rates and cost of 1 GB data to average USD 1.9 during January-March 2017.
"Stiff competition, price war, reduced revenue have trapped telecom sector into highly leveraged with interest coverage ratio turning less than 1 since third quarter of 2016-17," the survey said.
However, what's worrying is that the share of the telecom sector in the non-performing assets (NPAs) has now increased, it said.
The adjusted gross revenue (earnings from sale of telecom services) of the top three telecom companies in India - Bharti Airtel, Vodafone India and Idea Cellular declined by 7.98 per cent, 5.14 per cent and 4.91 per cent respectively during third quarter of 2016-17 compared to the previous quarter.
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It noted that earnings of telecom operators before interest and taxes by sales ratio also declined and at the same time industry faced high spectrum charges.
The survey said India outpaced the US to become second largest smartphone market in the world with 275 million smartphone subscribers.
India already has the world's second largest telecom subscriber base.
The survey said Telecom Regulatory Authority of India recorded 7.7 per cent quarterly growth in the subscriber base to 1,127.4 million at the end of third quarter of 2016- 17.
"Reliance Jio Infocom recorded the highest net addition of 56.2 million subscribers which is much higher than other service providers like Idea (11.7 million) and Bharti Airtel (5.9 million) during third quarter of 2016-17," the survey said.