Section 90.1209 - Policies governing the use of the 4940-4990 MHz band(a) Channels in this band are available on a shared basis only and will not be assigned for the exclusive use of any licensee.(b) All licensees shall cooperate in the selection and use of channels in order to reduce interference and make the most effective use of the authorized facilities. Licensees of stations suffering or causing harmful interference are expected to cooperate and resolve this problem by mutually satisfactory arrangements. If licensees are unable to do so, the Commission may impose restrictions including specifying the transmitter power, antenna height, or area or hours of operation of the stations concerned. Further, the Commission may prohibit the use of any 4.9 GHz channel under a system license at a given geographical location when, in the judgment of the Commission, its use in that location is not in the public interest.(c) Licensees will make every practical effort to protect radio astronomy operations as specified in § 2.106 , footnote US311 of this chapter.(d) Stations must be placed into operation within twelve (12) months from the date of grant in accordance with § 90.155 . Licensees of temporary fixed stations must place at least one such station in operation within twelve months of license grant. 68 FR 38639 , June 30, 2003, as amended at 88 FR 12571 , Feb. 28, 2023