back channel

Return channels are components of communication links between end users and service providers. They have a different technical design than the back channels. In contrast to the latter, the return channel is usually narrower-band and can be supported by other protocols.

Particularly in connection with interactive distribution services, where the high bandwidth is required by the home channel, the return channel has a narrowband structure because it only transmits information and control data. Typical examples are ADSL and digitalvideobroadcasting( DVB). In terms of the transmission direction, the downstream channel is referred to as the downstream, while the return channel is referred to as the upstream.

The downstream and return channels can be implemented on one and the same medium, but they can also be transmitted via different media. An example of a return channel implemented on a different medium is the affordable interactive distribution services, where the return channel is carried over the telephone network.

In broadband networks, the return channels form the connection from the data terminal to the head-end station.