Indeed, the radio access network (RAN) NB-IoT, LTE, LoRaWAN, etc. are just the communication link between UEs and satellites. To make this link useful a link to the core-network on earth should be established. This latter link is known as the feeder link in SatCom terminology and is established between the satellite and large ground-stations. The service link must provide sufficient capacity for the cumulative RAN information (and then some other telemetry) to be exchanged which is why ground-station typically have large steerable antennas and a large transmission power.