Medhavi Arora

India's richest man is rolling out a $20 billion mobile network that could bring lightening-fast Internet to hundreds of millions of people.

Indian consumers are already celebrating the arrival of Mukesh Ambani's new Reliance Jio service, seizing on the billionaire's promise to deliver rock bottom prices and download speeds that will enable streaming video. The 4G network, which reaches more than 80 percent of the country, officially went live with a set of generous introductory offers. Indians will be able to use Jio for free until the end of 2016, and pay as little as 149 rupees ($2.25) a month for data after that. "Anything and everything that can go digital is going digital -- at an exponential rate," Ambani told investors last week at his company's annual general meeting. "Life is going digital."