research and development, engineering studies, economic analyses, or other activities intended to improve the efficiency and effectiveness of the spectrum use of Federal entities in order to make available frequencies for reallocation for non-Federal use or shared Federal and non-Federal use, or a combination thereof, and for auction in accordance with such reallocation, that are conducted by the NTIA after the date of the enactment of this subsection, regardless of whether the NTIA conducts such activities using amounts transferred to the NTIA under paragraph (1). (3) Frequencies described The frequencies described in this paragraph are frequencies that— (A) are assigned to a Federal entity