The course aims to offer the student an overview of satellite radio communication systems, to highlight their typical and critical aspects from a design point of view and to provide the basic criteria for their design. The radio link equations are presented and the causes of possible performance degradation (noise, interference, nonlinear distortion, latency, Doppler effects, abnormal propagation in the troposphere, etc.) are analyzed. Problems relating to the application of multiple access techniques divided by frequency, time, code and space in the satellite area are illustrated. Some applications of satellite networks to services (broadcasting, access to global voice / data networks) are also covered.