§  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. Mobile and portable transmitters that only
   operate on the low power channels designated in § § 90.531(b)(3),
   90.531(b)(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) The following provisions apply to licensees operating in the
   channels designated in § 90.531(b)(5) or § 90.531(b)(6).

   (1) With the exception of licensees designated in paragraph (d)(2) of
   this section, after December 31, 2014, licensees may only operate in
   voice mode in these channels at a voice efficiency of at least one
   voice path per 6.25 kHz of spectrum bandwidth.

   (2) Licensees authorized to operate systems in the voice mode on these
   channels from applications filed on or before December 31, 2014, may
   continue operating in voice mode on these channels (including
   modification applications of such licenses granted after December 31,
   2014, for expansion or maintenance of such systems) at a voice
   efficiency of at least one voice path per 12.5 kHz of spectrum
   bandwidth until December 31, 2016.

   (3) The licensees designated in paragraph (d)(2) of this section must,
   no later than January 31, 2017, file a declaration through the
   Universal Licensing System that they are operating these channels at a
   voice efficiency of at least one voice path per 6.25 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]