§  90.537   Trunking requirement.

   (a) General use channels. All systems using six or more narrowband
   channels in the 769-775 MHz and 799-805 MHz frequency bands must be
   trunked systems, except for those described in paragraph (b) of this
   section.

   (b) Interoperability 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.

   [ 66 FR 10636 , Feb. 16, 2001, as amended at  72 FR 48861 , Aug. 24, 2007]