§  27.75   Basic interoperability requirement.

   (a)(1) Mobile and portable stations that operate on any portion of
   frequencies in the paired 1755-1780 MHz and 2155-2180 MHz band must be
   capable of operating on all frequencies in the paired 1710-1780 MHz and
   2110-2180 MHz band, using the same air interfaces that the equipment
   utilizes on any frequencies in the paired 1710-1780 MHz and 2110-2180
   MHz band.

   (2) Mobile and portable stations that operate on any portion of
   frequencies in the 600 MHz band must be capable of operating on all
   frequencies in the 600 MHz band using the same air interfaces that the
   equipment utilizes on any frequencies in the 600 MHz band.

   (3) Mobile and portable stations that operate on any portion of
   frequencies in the 3700-3980 MHz band must be capable of operating on
   all frequencies in the 3700-3980 MHz band using the same air interfaces
   that the equipment utilizes on any frequencies in the 3700-3980 MHz
   band.

   (4) Mobile and portable stations that operate on any portion of
   frequencies in the 3450-3550 MHz band must be capable of operating on
   all frequencies in the 3450-3550 MHz band using the same air interfaces
   that the equipment utilizes on any frequencies in the 3450-3550 MHz
   band.

   (b) The basic interoperability requirement in paragraph (a) of this
   section does not require a licensee to use any particular industry
   standard. Devices may also contain functions that are not operational
   in U.S. Territories.

   [ 79 FR 32413 , June 4, 2014, as amended at  79 FR 48539 , Aug. 15, 2014;
    85 FR 22882 , Apr. 23, 2020;  86 FR 17954 , Apr. 7, 2021]