There is a long history of the development of satellites system from a communications point of view. Some important events are shown below in a tabular form:
||Arthur C. Clarke publishes an essay titled "Extra Terrestrial Relays"
||First satellite, SPUTNIK
||First Reflecting communication satellite, ECHO
||First Geostationary satellite, SYNCOM
||First Commercial geostationary satellite, "Early Bird" (INTEKSAT I): 240 duplex telephone channels or 1 TV channel, 1.5 year lifetime.
||Three MARISAT satellites for maritime communication.
||First mobile satellite telephone system, INMARSAT - A
||First satellite system for mobile phones and data communication, INMARSAT -C
||First digital satellite telephone system
||Global satellite systems for small mobile phones.