The much awaited spectrum auction, wherein 8 companies are bidding to acquire airwaves in four bands, started on Wednesday.

The auction is the biggest ever sale of 2G and 3G airwaves which may fetch the government over Rs. 82,000 crore.

A total of 380.75 MHz of spectrum in three bands — the premium 900 MHz band, 1,800 MHz and 800 MHz — is put on sale besides 5 MHz in the 2,100 MHz band across 17 out of 22 telecom areas in the country.

Based on the reserve price, the government is estimated to garner over Rs. 82,000 crore. Most of the spectrum put up for auction is presently held by Airtel, Vodafone, Idea Cellular and Reliance Telecom. Their licences are expiring in 2015-16.

Mobile licences for Idea Cellular’s nine circles, six circles of Airtel and seven circles each of Vodafone and Reliance Telecom are coming up for renewal.

Overall, there are 29 licences in 18 service areas which will expire in 2015-16. These licences hold 184 MHz spectrum in the 900 MHz band and 34.2 MHz in 1,800 MHz band.

It is mandatory for these companies to bid for spectrum if they have to continue offering mobile and other telecom services as their permit is expiring. The government had raked in Rs. 62,162 crore from the last spectrum auction held in February 2014.