Vodafone India is set to launch its high-speed 4G service on Wednesday following the roll-out in Delhi-NCR last week.
The telecom operator acquired 4G (LTE) spectrum in Mumbai, Delhi, Kolkata, Kerala and Karnataka circles in the February 2014 auctions.
These circles together contribute close to 50 per cent of its total data revenue, making it the largest data revenue market for the firm.
Vodafone will be the second operator to roll out 4G service in Mumbai. Bharti Airtel has already launched the service to take on the new entrant Reliance Jio Infocom.
The service will be launched in a phased manner across Mumbai.
The user base for 3G service has grown 60 per cent year- on-year showing a healthy adoption of data, the company said.
It has already rolled out 4G-ready SIMs early in January in anticipation of the launch.