SPCP/MCPC, single/multiple channels per carrier.
SCPC stands for Single Channel Per Carrier.
SCPC is a form of satellite transmission where each channel is transmitted on a dedicated single carrier.
The alternative to SCPC is MCPC (Multiple Channel Per Carrier).
MCPC is more efficient than SCPC, but SCPC is still utilized for some satellite feeds. By using SCPC, satellite users are able to uplink to the same transponder from multiple locations.