The telecom sector in India has undergone significant changes over time, transitioning through various market structures. In its early days, it featured a monopolistic market structure with only a few government-owned players. In the post-independence period of the late 1990s-2000s, the sector opened up and many private and foreign firms entered, transitioning it to a monopolistically competitive market. Reliance Jio later disrupted the sector with cheap data plans, leading existing firms to lose market share. This has consolidated the sector to now feature only three major players - Vodafone Idea, Airtel, and Reliance Jio, raising the risk of a duopoly.