Sec. 21.3  Station authorization required.

    (a) No person shall use or operate apparatus for the transmission of 
energy or communications or signals by radio except under, and in 
accordance with, an appropriate authorization granted by the Federal 
Communications Commission. Except as otherwise provided herein, no 
construction or modification of a station may be commenced without an 
authorization from the Commission. Authorizations for domestic public 
fixed radio services are governed by the provisions of this part.
    (b) If construction and or operation may have a significant 
environmental impact as defined by Sec. 1.1307 of the Commission's 
rules, the requisite environmental assessment as prescribed in 
Sec. 1.1311 of this chapter must be filed with the application and 
Commission environmental review must be completed before construction of 
the station is initiated. See Sec. 1.1312 of this chapter.
[ 52 FR 37777 , Oct. 9, 1987, as amended at  55 FR 20397 , May 16, 1990;  61 FR 26673 , May 28, 1996]