With multiple channels per carrier (MCPC), several subcarriers are combined into a single bitstream before being modulated onto a carrier transmitted from a single location to one or more remote sites. This uses time-division multiplexing (TDM). It is a retronym of sorts, as it was the only way radio networks were transmitted ("piggybacked" on television networks) until SCPC.
In digital radio and digital television, an ensemble or other multiplex or multichannel stations can be considered MCPC, though the term is generally only applied to satellites.
The major disadvantage of MCPC is that all of the signals must be sent to a single place first, then combined for retransmission — a major reason for using SCPC instead.
Read more about this topic: Single Channel Per Carrier