Everyone in India has a cell phone. Not smart phones in most cases, but a phone. Service is cheap, phones are readily available and coverage is amazing. You can get a signal even in the Thar Desert near Jaisalmer.
While I watched the sun set over the sand dunes, the guy who owned the camel I rode spent most of his time on his cell phone. And there wasn't a cell tower in site. The camel trek, by the way, was one of the highlights of my trip.
In 2013 there were over 875 million cell phones in India.