Country's largest telecom operator Bharti Airtel has floated a request for proposal (RFP) to upgrade its 3G service networks.
The company has mentioned in the document that the network should be compliant in both 1800 Mhz and 900 Mhz bands.
"This RFP is to facilitate the selection of the supplier for the supply of best in class 3G network solution and related services," the document said.
Industry sources said meanwhile that the company has sought network compliance in both 900 Mhz and 1800 Mhz bands because there is no clarity on refarming policy yet and the company wants to keep options for both.
"Finally, after the spectrum issue is clear they may ask for final bid on either 900 Mhz or 1800 Mhz," said a source.
Telecom regulator Trai has recommended refarming - shifting of service operations of a company from one frequency band to another - but the government is yet to take a final call on the issue.
Bharti Airtel's licences in Delhi, Mumbai and Kolkata, where it holds spectrum in 900 Mhz band, are coming up for renewal next year.
As per a decision taken by the government earlier, the company has to vacate the 900 Mhz band and buy spectrum afresh to continue operations.
The spectrum auction for both 900 Mhz and 1800 Mhz bands is likely to be held in January next year.
The Telecom Commission has recommended a reserve price of Rs 360 crore for Delhi, Rs 328 crore for Mumbai and Rs 125 crore for Kolkata per mega hertz in 900 Mhz band.