Single channel per carrier

• simple and reliable technology • low-cost equipment • any bandwidth (up to a full transponder) • usually 64 kbit/s to 50 Mbit/s • easy to add additional receive sites (earth stations) ==Disadvantages==

• inefficient use of satellite bandwidth for burst transmissions, typically encountered with packet data transmission • usually requires on-site control • When used in remote locations, the transmitting dish must be protected. ==MCPC==

SCPC was the successor multiple channels per carrier (MCPC). With MCPC, several subcarriers are combined or multiplexed 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) as well as frequency-division multiplexing. 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. ==Frequency hopping==

SCPC became somewhat obsolete after the invention of frequency hopping. Frequency hopping (FHSS) is a system invented by Hedy Lamarr in which radio signals rapidly change frequency to avoid interception. FHSS required the use of MCPC, as SCPC cannot change frequency mid-broadcast. FHSS was the basis for many technological advancements like Wi-Fi, Bluetooth, and GPS, which could not have been achieved with SCPC. ==References==