SCPC Single Channel per Carrier

SCPC (Single Channel per Carrier) is a satellite transmission system with a separate carrier for each channel, as opposed to frequency or time division multiplexing - including DVB - which combines many channels on a single carrier.

The primary advantage of SCPC is the architecture which allows full connectivity between any sites in the network. SCPC allows to set-up quickly a satellite link (point-to-point or point-to-multipoint) without any need to gather other channels at the uplinking teleport. The incremental usage of the satellite transponder enables a flexible expansion of the network.

With regard to IP over satellite, SCPC/SCPC transmission is also the preferred choice for Voice-over-IP (VoIP) and other delay critical applications. Thanks to the missing multiplex, in the case of SCPC digital processing is straight forward, with the result of some 150 ms less latency compared to DVB/SCPC.

There are, however, several disadvantages in SCPC when compared with the other techniques. In a SCPC system, each data channel requires a separate satellite modem at each earth station, which increases cost in ground equipment and translates into a higher set-up fee for the customer. In a network of VSAT stations, the most important drawback often is the fact that SCPC is per definition a "dedicated bandwidth" technology. Thus SCPC/SCPC services do not allow to share the bandwidth available on the satellite among several or many VSAT stations - neither in the upstream nor in the downstream. The result is a less economic overall solution.