; and (3) include technical characteristics under which the bands described in subsection (d) may be employed for mobile or fixed terrestrial wireless operations, including any appropriate coexistence requirements. 5. 3 gigahertz spectrum (a) Between 3100 megahertz and 3550 megahertz Not later than 18 months after the date of enactment of this Act, and in consultation with the Commission and the head of each affected Federal agency (or a designee thereof), the Secretary shall submit to the Commission and the appropriate committees of Congress a report evaluating the feasibility of allowing commercial wireless services, licensed or unlicensed, to share use of the frequencies between 3100 megahertz and 3550 megahertz. (b) Between 3700 megahertz and 4200 megahertz Not later than 18 months after the date of enactment of this Act, after notice and an opportunity for public comment, and in consultation with the Secretary and the head of each affected Federal agency (or a designee thereof), the Commission shall submit to the Secretary and the appropriate committees of Congress a report evaluating the feasibility of allowing commercial wireless services, licensed or unlicensed, to share use of the frequencies between 3700 megahertz and 4200 megahertz. (c) Requirements A report under subsection (a) or subsection (b) shall include the following: (1) An assessment of the operations of Federal entities that operate Federal Government stations authorized to use the frequencies described in that subsection. (2) An assessment of the possible impacts of such sharing on Federal and non-Federal users already operating on the frequencies described in that subsection. (3) The criteria that may be necessary to ensure shared licensed or unlicensed services would not cause harmful interference to Federal or non-Federal users already operating in the frequencies described in that subsection. (4) If such sharing is feasible, an identification of which of the frequencies described in that subsection are most suitable for sharing with