An automatic transmission system (ATS) is an automated system designed to keep a broadcast radio or television station's transmitter and antenna system running without direct human oversight or attention for long periods. Such systems are occasionally referred to as automated transmission systems to avoid confusion with the automatic transmission of an automobile.
A sign-on (or start-up in Commonwealth countries except Canada) is the beginning of operations for a radio or television station, generally at the start of each day. It is the opposite of a sign-off (or closedown in Commonwealth countries except Canada), which is the sequence of operations involved when a radio or television station shuts down its transmitters and goes off the air for a predetermined period; generally, this occurs during the overnight hours although a broadcaster's digital specialty or sub-channels may sign-on and sign-off at significantly different times than its main channels.
Like other television programming, sign-on and sign-off sequences can be initiated by a broadcast automation system, and automatic transmission systems can turn the carrier signal and transmitter on/off by remote control.
Broadcast automation incorporates the use of broadcast programming technology to automate broadcasting operations. Used either at a broadcast network, radio station or a television station, it can run a facility in the absence of a human operator. They can also run in a live assist mode when there are on-air personnel present at the master control, television studio or control room.
The radio transmitter end of the airchain is handled by a separate automatic transmission system (ATS).