§  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]