Communications over geostationary satellites are described and analyzed in detail. The principles of Satcom networks, coverage, EIRP and receive sensitivity are presented. Waveform concepts including modulation, Forward Error Correction encoding are explained. The methodology to establish link budgets is given. The architecture for a communication payloads is given, and ground terminal and satellite antenna design and analysis presented. Ground terminals types from TV receive terminals over VSATs up to hub stations are explained. Finally, the book contains an introduction to advanced Satcom systems such as High Throughput Satellite systems and constellation based networks for Mobile Satellite Services for the example of IRIDIUM.