§  90.535   Modulation and spectrum usage efficiency requirements.

   Transmitters designed to operate in 769-775 MHz and 799-805 MHz
   frequency bands must meet the following modulation standards:

   (a) All transmitters in the 769-775 MHz and 799-805 MHz frequency bands
   must use digital modulation. Mobile and portable transmitters may have
   analog modulation capability only as a secondary mode in addition to
   its primary digital mode except on the interoperability channels listed
   in § 90.531(b)(1). Analog modulation is prohibited on the
   interoperability channels. Mobile and portable transmitters that only
   operate on the low power channels designated in § 90.531(b)(3) and (4)
   are exempt from this digital modulation requirement.

   (b) Transmitters designed to operate in the narrowband segment using
   digital modulation must be capable of maintaining a minimum data
   (non-voice) rate of 4.8 kbps per 6.25 kHz of bandwidth.

   (c) Transmitters designed to operate in the wideband segment using
   digital modulation must be capable of maintaining a minimum data
   (non-voice) rate of 384 kbps per 150 kHz of bandwidth.

   (d) Transmitters designed to operate on the channels listed in
   paragraphs (b)(2), (5), (6), and (7) of § 90.531 must be capable of
   operating in the voice mode at an efficiency of at least one voice path
   per 12.5 kHz of spectrum bandwidth.

   [ 63 FR 58651 , Nov. 2, 1998, as amended at  65 FR 53645 , Sept. 5, 2000;
    65 FR 66655 , Nov. 7, 2000;  67 FR 76701 , Dec. 13, 2002;  70 FR 21673 ,
   Apr. 27, 2005;  72 FR 48861 , Aug. 24, 2007;  79 FR 71326 , Dec. 2, 2014;
    81 FR 66833 , Sept. 29, 2016]