47 U.S.C. § 1505
Unlicensed services in guard bands
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
The Commission may not permit any use of a guard band under this section that would cause harmful interference to a licensed service or a Federal service.
Nothing in this section shall be construed as limiting the Commission or the Assistant Secretary of Commerce for Communications and Information from otherwise making spectrum available for licensed or unlicensed use in any frequency band in addition to guard bands, including under section 1502 of this title, consistent with their statutory jurisdictions.