The Union Cabinet is understood to have approved holding of a mega spectrum auction for 5G telephony — with the sale valued at over Rs 4. 5 lakh crore just at the reserve price — and the process is likely to kick off over the next two months. Sources said that the Cabinet, chaired by Prime Minister Narendra Modi, gave a goa head to the spectrum sale that will see the government auction over 1 lakh MHz of mobile airwaves at one go, which is a record in terms of the total quantum put up for sale.