CEA-909-A describes an antenna control subsystem for receiving
terrestrial transmissions. The primary use is to facilitate
television reception. The receiver controls the antenna apparatus
to optimize the signal automatically for best reception by
adjusting its configuration.
CEA-909-A allows any receiver to operate with any antenna,
regardless of manufacturer. CEA-909-A defines the data algorithms
used, connection standards, and other requirements. The antenna
configuration is neither specified nor implied, leaving certain
antenna design considerations to the manufacturer.