§  73.402   Definitions.

   (a) DAB. Digital audio broadcast stations are those radio stations
   licensed by the Commission and use the In-band On-channel ("IBOC")
   system for broadcasting purposes.

   (b) In Band On Channel DAB System. A technical system in which a
   station's digital signal is broadcast in the same spectrum and on the
   same channel as its analog signal.

   (c) Hybrid DAB System. A system which transmits both the digital and
   analog signals within the spectral emission mask of a single AM or FM
   channel.

   (d) Extended hybrid operation. An enhanced mode of FM IBOC DAB
   operation which includes additional DAB subcarriers transmitted between
   the analog FM signal and the inner edges of the primary DAB sidebands.

   (e) Primary AM DAB Sidebands. The two groups of hybrid AM IBOC DAB
   subcarriers which are transmitted 10 to 15 kHz above carrier frequency
   (the upper primary DAB sideband), and 10 to 15 kHz below carrier
   frequency (the lower primary DAB sideband).

   (f) Multicasting. Subdividing the digital bitstream into multiple
   channels for additional audio programming uses.

   (g) Datacasting. Subdividing the digital bitstream into multiple
   channels for additional data or information services uses.