Single channel per carrier (SCPC) refers to using a single signal at a given frequency and bandwidth. Most often, this is used on broadcast satellites to indicate that radio stations are not multiplexed as subcarriers onto a single video carrier, but instead independently share a transponder. It may also be used on other communications satellites, or occasionally on non-satellite transmissions. With multiple channels per carrier (MCPC), several sub-carriers are combined into a single bit-stream before being modulated onto a carrier transmitted from a single location to one or more remote sites. This uses time-division multiplexing (TDM).