One-way satmodems (DVB-IP modems ) use a return channel not based on communication with the satellite, such as telephone or cable.
Two-way satmodems (DVB-RCS modems, also called astromodems) employ a satellite-based return channel as well; they do not need another connection. DVB-RCS is ETSIstandardEN 301 790.
... historian. He was an Ostrogoth and was a notary of Gothic kings in Italy. At the time of Justinian, he was a Christian and possibly bishop of Croton. In approximately 580, ...