"We will come out with the NIA (Notice Inviting Application) early next week... This will set the process in place," Telecom Secretary J S Deepak told PTI.
He said the auction of mobile airwaves will be held by September-end.
The NIA is the main document of spectrum auction which carries all details of radiowaves being put up for sale, rules, price and the like and is legally binding on both the government as well as bidders.
The government expects to raise at least Rs 64,000 crore from the auction of about 2,300 Mhz of spectrum and Rs 98,995 crore from various levies and services in the telecom sector this financial year.
As per the decision, spectrum to be sold in the bands of 700 MHz, 800 MHz, 900 MHz, 1800 MHz, 2100 MHz, 2300 MHz and 2500 MHz will attract SUC at the rate of 3 per cent of the adjusted gross revenue.