Definition: Digital sub-channels are channels that broadcast stations have in addition to their primary feed.
Sub-channels are made possible by digital technology. This is one advantage of digital television over analog - the ability to transmit multiple streams of video content within a single signal.
Examples:
My local CBS affiliate operates on 42.1. They have a digital sub-channel on 42.2. My local ABC affiliate also utilizes a sub-channel, which they use to show 24-hours of weather.
