"Vodafone has already launched its high speed 4G services in Kerala. The intensity of its roll-out will continue with major metros like Mumbai, Kolkata, Bengaluru and Delhi to be launched by March 2016," the company said in a statement.

The second largest telecom operators in the country has started issuing 4G-ready SIMs in Mumbai.

"We want our customers to be 4G-ready so that they can start experiencing the benefits of high-speed mobile Internet services as soon as they are launched commercially. Hence, this facility to upgrade to 4G-ready SIMs in advance," Vodafone India Business Head Mumbai Ishmeet Singh said.

He said the company is 'fully geared up to launch' 4G services in 1800 Mhz band in Mumbai very soon. Vodafone is also making arrangements of home delivery of 4G-ready SIMs for its premium high-value customers in Mumbai and formal communication is being sent out to all these customers with details of the initiative, the statement said.