Global MC is in Calgary. The signal leaving Calgary goes to the transmitters, cable and satellite BDUs without further switching. The exception is a few affiliates that have their own MC functions. Feeding a separate SD channel allows Global to select center-cut or letterbox in their MC and not rely on remotely located aspect ratio converters to generate the SD feed. Global's analog transmitters will use the SD feed from satellite or fibre. Smaller cable companies and MATV systems (institutions, hotels, seniors homes)may be using off-air ATSC signals for their SD digital or analog source so making it visible as a sub-channel will simplify reception.