Tata Teleservices [Get Quote] is gearing up for GSM-based telecom service and has recently received spectrum for three circles.

"We have received spectrum for Orissa, Chennai and he rest of Tamil Nadu," company's Head East & COO Kolkata circle, Sajiv Sinha said on Tuesday on the sidelines of launch of a cordless Walky Talky fixed phone in Kolkata.

Asked about rollout plan for GSM-based mobile service, he said no definite timeframe had been decided as rollout and deployment of infrastructure was in the planning stage and would depend on spectrum allocation.

As per spectrum allocation condition, the company would launch the service within the next one year, Sinha said.

The department of telecommunication in March allowed TTSL to introduce GSM-based telecom service in 20 circles.

Sources said national rollout would not be difficult and it would not take more than six to eight months to deploy the necessary infrastructure.

TTSL would use its existing CDMA-base station network for the GSM launch.

"The investment will be minimal as we will use the base stations of existing CDMA service. Th rest of the infrastructure will cost a fraction of what we have invested in base station installation," sources said.

TTSL has about 14,000 base stations for CDMA service.