The country is poised to take a major step towards the 5G era with its biggest-ever spectrum auction beginning Tuesday. A total of 72 GHz of airwaves will be up for bidding, with participation from four entities — Reliance Jio, Bharti Airtel, Vodafone Idea and Adani Data Networks, a subsidiary of the Adani Group. They have submitted earnest money deposits (EMDs) — a key marker of bidding intent — to the Department of Telecommunications (DoT). Reliance Jio has put in Rs 14,000 crore, compared to Rs 5,500 crore by Bharti Airtel, Rs 2,200 crore by Vodafone Idea, and Rs 100 crore by the Adani Group.