Editing Broadcast auxiliary service (section)

{{Short description|Radio frequency used by a radio or TV station}}
A '''broadcast auxiliary service''' ('''BAS''') is any [[radio frequency]] system used by a [[radio station]] or [[TV station]], which is not part of its direct [[broadcasting|broadcast]] to listeners or viewers.  These are essentially internal-use [[backhaul (telecom)|backhaul]] channels not intended for actual [[Television reception|reception]] by the public, but part of the [[airchain]] required to get those signals back to the broadcast studio from the field. usually to be integrated into a live production.

Examples include:
*[[studio/transmitter link]] (STL)
*[[transmitter/studio link]] (TSL)
*[[remote pickup unit]] (RPU)
*[[electronic news gathering]] (ENG)

Several of these bands exist, but the most frequently used band is the 2 GHz [[microwave]] BAS band for point-to-point transmission from mobile newsgathering units to mountaintop receivers.

Seven 12-MHz wide channels exist in the band. In North America, [[DVB-T]], precisely the same modulation technique as European Broadcast, is used, using a constellation of [[QPSK]], [[16QAM]], or [[64QAM]], enabling sufficient digital bandwidths at 6 MHz deviation for transmission of an [[MPEG]] [[transport stream]] at 10 or more megabits per second, producing three "lower", "center", and "upper" overlapping 6 MHz channels within each 12 MHz channel.
[[File:BAS-2018.png|center|frameless|800x800px|2GHz FCC Band Plan with 6MHz Subdivisions]]