47 CFR § 90.627 - Limitation on the number of frequency pairs that may be assignable for trunked systems and on the number of trunked systems.
(b) No non-SMR licensee will be authorized an additional trunked system within 64 kilometers (40 miles) of an existing trunked system, except where:
(1) The additional trunked system will be used to provide radio facilities for a single entity, where the additional system is justified on the basis of the requirements of the proposed single user; or,
(2) The licensee's existing trunked system is loaded to at least 70 mobile and control stations per channel.
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