We need to Understand that Airtel dont have Fiber Optic Internet. Airtel just uses Vectorisation Technology in same old Copper lines.
Now with vectoring, what it does is to eliminate all the sound , all the interference in lines, the decade old or so legacy copper lines. The tech was developed by many such as alcatel lucent (now purchased by nokia), nokia themselves and ericsson. Alcatel lucent was the first to roll it out commercially in western markets.
With vectoring, the main benefit is that LAST MILE INFRA, which is copper need not to be changed , and saves money for an operator.
For example: Airtel has covered street A with one main feeder FIBER, and from junction box, it is the same old copper wire that takes connection to your home. Here, the vectoring will enable to deliver “fiber like speeds” with same old infra.