In India, only 3 private ISPs have a total monopoly on landline broadband bandwidths(besides the govt. owned BSNL). Out of these, Reliance owns Flag Telecom, one of the world's largest undersea fibre optic internet bandwidth pipeline.
Tata has their tie
ups with such international undersea fibre optic lines landing in South and Western India. Airtel also had similar tie ups, and their dedicated direct undersea line from Singapore. Now, Airtel is going to have access to a huge undersea pipeline from their participation in one of the world's largest such project called the "Unity" project. This in partnership with
Google is already ready, and will allow Airtel to offer still larger amounts of broadband to corporates and individuals. That must be one reason Airtel is getting generous now(and due to competition...) to offer automatic double speeds. However, the sad part is that All these 3 ISPs due to the monopoly have not reduced the prices and have kept the speeds also at a very low rate, to keep us the users hungry forever, so that whenever they increase the speed and offer the next level for a few 100 Rs. more, they know we will jump at it. All these 3 ISPs have been doing it for years now. It is high time that TRAI jumps in and make either 1mbps or 2mbps as the basic minimum speed as the definition of "broadband" in India which is a pathetic 256kbps as of today, legally speaking.
Your information is slightly out of date and inaccurate.
1. Bharti fully owns i2i, an 8 terabit capacity cable between Chennai and Singapore. They are also on the Se-Me-We 4 consortium (along with Tata), as well as the EIG and I-Me-We consortiums. Each of these cables has at least 1 terabit, and some are only operating at single digit (