Communication satellites, low orbit satellite, medium orbit satellite, geostationary satellite antenna and earth station antenna, modulation and demodulation, coding and decoding in satellite communication system, radio wave propagation between earth and satellite, ionosphere and its effect to satellite signal propagation, satellite signal attenuation due to atmosphere, noise in satellite communication, transponder of satellite, signal transmission via satellite, communication system between satellite and earth stations, oscillation of satellite signal, attenuation of satellite signal in C, Ku and Kc bands due to rainfall, effects of ionospheric electron density to satellite signal.