Airtel, Vodafone and Idea are pressing the Indian government to reallocate part of the country’s CDMA spectrum for GSM-based services, arguing the move is justified by the declining interest among operators in CDMA.

The three Indian operators have written to the country’s Department of Telecommunications (DoT) suggesting that part of the existing 800 MHz spectrum band be reallocated from CDMA to GSM.

They say the country’s 800 MHz spectrum should be harmonised with the international band plan so that it is treated as an “extended” 900 MHz band. This would increase availability of GSM spectrum by up to 10 MHz, or over 40 percent, according to the letter.

The operators want frequencies from 880 MHz onwards reclassified as GSM rather than CDMA. Currently, the allocation for GSM starts at 890 MHz.

“With the diminishing interest of operators in CDMA and the reducing subscriber base of the technology, we believe that we need to harmonise and reconfigure the existing Indian CDMA band in line with the global practice,” said the letter.

CDMA operator Tata Teleservices will close its service in Jammu and Kashmir by 17 January. An Indian court cancelled the operator’s licences, including Jammu and Kashmir, in February 2012. However, the operator did have the option to participate in a re-auction of frequencies but decided the reserve price was too high.

Tata’s decision not to participate in the upcoming auction for spectrum in the three circles was first reported earlier this month. It has left the government with no potential bidder willing to use frequencies for CDMA services.