The 2,300-plus MHz of airwaves on the block for telecom operators are in seven bands -- 700 MHz, 800 MHz, 900 MHz, 1,800 MHz, 2,100 MHz, 2,300 MHz and 2,500 MHz. In the previous auction 470.75 MHz was on offer, which is set to fetch the exchequer $17 billion during the tenure of licence.