Sources said Trai in a recent letter to DoT asked about the exact range of frequencies in 900MHz and 1800MHz bands allotted to telecom service providers, government agencies and frequencies which are lying vacant in each service area, Reports PTI.

The process will determine the reserve price of spectrum to be auctioned across 18 out of the 22 telecom service areas across the country for 900MHz and 1800MHz bands, used for providing mobile services based on GSM technology standard.

According to sources, Department of Telecom (DoT) has already provided the details to Trai about the quantum of available spectrum including the details of frequencies along with status of quantum of contiguous and non-contiguous spectrum in 900MHz and 1800MHz bands.

The source, however, added that the Authority will give recommendations even if DoT did not provide it with the requisite details.

In December 2015, 4 licences of Bharti Airtel, 7 each of Idea Cellular and Reliance Telecom and 6 of Vodafone will complete their 20-year term and would require renewal.