§  90.537   Trunking requirement.

   (a) General use and State License channels. All fixed transmitter sites
   using six or more narrowband channels in the 769-775 MHz and 799-805
   MHz frequency bands must be trunked, except for those described in
   paragraph (b) of this section. This paragraph does not apply to
   Vehicular Repeater Systems (MO3) authorized on the General Use and
   State License channels listed in § 90.531(b).

   (b) Interoperability and low power channels. Trunking is permitted only
   on Interoperability channels specified in § 90.531(b)(1)(iii). Trunked
   use must be strictly on a secondary, non-interference basis to
   conventional operations. The licensee must monitor and immediately
   release these channels when they are needed for interoperability
   purposes. All systems using narrowband low power channels listed in
   § 90.531(b)(3) and (4) are exempt from the trunking requirements
   described in paragraph (a) of this section.

   [ 79 FR 39340 , July 10, 2014, as amended at  83 FR 30367 , June 28, 2018]