A satellite communication system includes a satellite, satellite base station (eNodeB or gNodeB) and a user equipment (UE). The satellite provides a number of satellite beams, and each satellite beam includes multiple cells. The base station communicates with the UE via a satellite using a narrowband internet of things (NB-IoT) waveform and an enhanced protocol. In particular, the base station and UE perform carrier aggregation by adding and/or deleting carriers in a cell, and the base station and UE perform a higher-order modulation and coding scheme (MCS) processing to support high data rates for user data transport.