After public notice and comment, and in consultation with the Assistant Secretary of Commerce for Communications and Information and the head of each affected Federal agency (or a designee thereof), with respect to frequencies allocated for Federal use, the Commission shall adopt rules that permit unlicensed services where feasible to use any frequencies that are designated as guard bands to protect frequencies allocated after March 23, 2018, by competitive bidding under section 309(j) of this title, including spectrum that acts as a duplex gap between transmit and receive frequencies.