The Authority in performing its functions under sections 58, 59 and 60 shall take into account

(a) the impact of the spectrum plan on existing and future use,

(b) the efficient use of the spectrum,

(c) any applicable regional agreements, standards and arrangement,

(d) any applicable international standards, International Telecommunication Union Treaties and other international agreement, and

(e) any other relevant matters having regard to the circumstances of the case.