prescribed technical and operating parameters. (4) Where the frequencies applied for are not available, the Commission may assign frequencies in an alternative frequency band. (5) The Commission may impose such conditions as it may consider necessary for the use of the assigned frequencies. 8. Obligations of licensees. (1) A licensee who has been assigned frequencies bands for use shall— (a) maintain and provide, at the Commission’s request, an inventory of frequencies assigned; (b) keep the licence in force by regular payment of annual fees prescribed by the Commission from time to time; (c) put into use the assigned frequencies within the period specified by the Commission; (d) use such measures as may be prescribed by the Commission to eliminate unauthorized emissions, harmful interference or illegal use of the spectrum; (e) optimize the utilization of frequency spectrum resource in the manner prescribed by the Commission from time to time; and (f) implement all the measures prescribed by the Commission from time to time. (2) The Commission may where it considers it necessary, require a licensee to migrate to a new frequency band. (3) The Commission shall implement the migration through an arrangement that shall not impose unreasonable burden to the licensee involved. (4) A licensee shall not make material change to a licensed station or change the station parameters specified in the licence, without a written authorization from the Commission. (5) A licensee shall require the written consent of the Commission where a licensee proposes to-