The telecom sector's roller coaster over the past four years

India's telecom sector has transformed drastically over the past decade — for the good and the bad. Its roller coaster growth has three companies — Vodafone idea, Bharti Airtel and Reliance Jio — accounting for over 90% of the revenue market share.

Yet, the industry has been saddled with losses in excess of ₹40,000 crore.

Just when everyone thinks that the worst in the sector is over, a new bolt from the blue strikes.

This time it's the Supreme Court's ruling to uphold the Department of Telecommunications' (DoT) definition of adjusted gross revenue (AGR). It means two telecom companies have to shell out as much as ₹92,000 crore.

Here are the many events that changed the course of the sector many times: