47 CFR § 22.165 - Additional transmitters for existing systems.
A licensee may operate additional transmitters at additional locations on the same channel or channel block as its existing system without obtaining prior Commission approval provided:
(a) International coordination. The locations and/or technical parameters of the additional transmitters are such that individual coordination of the channel assignment(s) with a foreign administration, under applicable international agreements and rules in this part, is not required.
(b) Antenna structure registration. Certain antenna structures must be registered with the Commission prior to construction or alteration. Registration requirements are contained in part 17 of this chapter.
(c) Environmental. The additional transmitters must not have a significant environmental effect as defined by §§ 1.1301 through 1.1319 of this chapter.
(d) Paging and Radiotelephone Service. The provisions in this paragraph apply for stations in the Paging and Radiotelephone Service.
(1) The interfering contours of the additional transmitter(s) must be totally encompassed by the composite interfering contour of the existing station (or stations under common control of the applicant) on the same channel, except that this limitation does not apply to nationwide network paging stations or in-building radiation systems.
(2) [Reserved]
(3) The additional transmitters must not operate on control channels in the 72–76 MHz, 470–512 MHz, 928 MHz, 932 MHz, 941 MHz or 959 MHz frequency ranges.
(e) Cellular Radiotelephone Service. The service area boundaries (SABs) of the additional transmitters, as calculated by the method set forth in § 22.911(a), must not cause an expansion of the Cellular Geographic Service Area (CGSA), and must not extend outside the CGSA boundary into Unserved Area unless such extension is less than 130 contiguous square kilometers (50 contiguous square miles). The licensee must seek prior approval (using FCC Form 601) regarding any transmitters to be added under this section that would cause an expansion of the CGSA, or an SAB extension of 130 contiguous square kilometers (50 contiguous square miles) or more, into Unserved Area. See §§ 22.912, 22.953.
(f) Air-ground Radiotelephone Service. Ground stations may be added to Commercial Aviation air-ground systems at previously established ground station locations, pursuant to § 22.859, subject to compliance with the applicable technical rules. This section does not apply to General Aviation air-ground stations.
(g) Rural Radiotelephone Service. A “service area” and “interfering contours” must be determined using the same method as for stations in the Paging and Radiotelephone Service. The service area and interfering contours so determined for the additional transmitter(s) must be totally encompassed by the similarly determined composite service area contour and predicted interfering contour, respectively, of the existing station on the same channel. This section does not apply to Basic Exchange Telecommunications Radio Systems.
(h) Offshore Radiotelephone Service. This section does not apply to stations in the Offshore Radiotelephone Service.
(i) Provision of information upon request. Upon request by the FCC, licensees must supply administrative or technical information concerning the additional transmitters. At the time transmitters are added pursuant to this section, licensees must make a record of the pertinent technical and administrative information so that such information is readily available. See § 22.303.