59 Power to issue spectrum licence 41.—(1) The Authority has the power to issue spectrum licences and only in accordance with the prescribed procedures and requirements. (2) The procedures and conditions for licensing of radio spectrum to be used for the provision of telecommunications services must— (a) where the Authority considers the radio spectrum bands to be a scarce resource, use a tendering process; and provide for a single application process covering both the radio spectrum under this Division and the telecommunications service under Division 3. (6) 42.—(1) Duration and vacation of spectrum licence A spectrum licence may be issued for such duration, not exceeding 15 years, to be specified in the licence which— (a) may be issued concurrently with the terms of the telecommunications service licence; or {b) shall take into account the need of the investor to earn a reasonable return on the investment over such duration period. (2) The Authority may— (a) vacate radio spectrum from licence holders which have been assigned radio spectrum but do not use it for provision of a service within a reasonable period of time where there is demonstrable demand from other carriers to use all or part of that spectrum efficiently; and {b) vacate radio spectrum bands from licence holders for the purpose of providing new telecommunications services according to recognised international rules in exchange for fair compensation and with notice of not less than one year. Division 3 — Telecommunications Numbering System 43.—(1) National numbering The Authority must establish and publish a numbering plan for telecommunications services and may make rules pursuant to that plan regarding the assignment and use of numbers by carriers. basis. (2) The Authority must assign numbers for telecommunications services to licensees on a non-discriminatory (3) For the purposes of subsection (1), the Authority must— (a) take account of relevant international standards; (6) ensure that sufficient numbers are available for the current and reasonably anticipated future needs of carriers; (c) have regard to the role that numbers can play in conveying useful information to consumers, including information about the type of service being used; {d) promote efficient use of numbers; (e) promote fair and open competition; (f) (g) as far as possible and subject to paragraphs (a) to (e), avoid the imposition of costs on consumers as a result of changes in the numbering system; and. ensure that any plan takes into account number portability to the extent it is implemented under section 44, Number portability 44, Subject to section 21, the Minister may, on the recommendation of the Authority, make regulations under section 82 requiring licensees to offer number portability if there is a reasonable likelihood of consumer demand for number portability.