communications technology satellite (CTS)
The term communications satellite is the generic term for satellites that serve communications. These are news satellites, amateur radio satellites, television satellites, telecommunications satellites, and satellites for other telecommunications services.
Which satellites are used for which communications service depends on the communications service, the size of the user group, and the constraints that can be placed on satellite transmission of time-sensitive signals.
Communications satellites provide a relay station between ground stations and receiving stations. The signals to be transmitted are sent via microwave usually in S-band, L-band and Ku-band from the ground station to the satellite, where they are received by the satellite antennas, processed and radiated via the transponder and the transmitting antenna to the earth where they are received by earth stations. Newer techniques also operate in the Ka-band between 27 GHz and 40 GHz. This frequency band can be used to transmit larger volumes of data, such as those found in clouds or Big Data, because of the bandwidth available. In another approach, laser light is used for transmission.
Depending on the information content, transmission can be narrowband, or otherwise broadband.