Article 63 Radio-frequency spectrum fees 1. The Authority may require licensees to pay fees for the right to use radio spectrum: a) In connection with the award of a licence pursuant to a competitive selection process or an assignment made pursuant to paragraph 6 of article 65; b) Periodically during the term of a licence; and c) In connection with the renewal of a licence. 2. Subject to the following paragraph, the Authority shall prescribe fees under the preceding paragraph in order to: a) Reflect the economic value of the radio-frequency spectrum; and b) Ensure the efficient use of radio-frequency spectrum resources, including the rationing of the use of radio-frequency spectrum in frequency bands, in particular the frequency bands for which the Authority expects demand to exceed supply. 3. The Authority may not prescribe fees for the right to use radio spectrum: a) Under subparagraphs b) and c) of paragraph 1 of this article before a period of five years has elapsed from the date of the entry into force of the present Decree-law; and b) Notwithstanding any other article of the present Decree-law, in the case of radiofrequency spectrum licences issued pursuant to article 81 during the term of such licences. 4. The Authority may prescribe procedures, rules and guidelines for the payment of fees pursuant to this article. 5. The imposition by the Authority of requirements pursuant to this article shall be subject to paragraph 4 of article 19. Article 64 Radio-frequency spectrum licensing exemptions 1. The Authority may set parameters within which the use of frequencies and the operation of radio equipment shall be exempt from the licensing requirement set forth in article 61. 2. In considering establishing any exemptions pursuant to the preceding paragraph, the Authority shall take into account: