Secrecy Capacity for Satellite Networks under Rain Fading

The transmission of confidential information over satellite links operating at frequencies above 10 GHz is studied in this paper. The major factor impairing the link performance at these frequencies is rain attenuation, a physical phenomenon exhibiting both spatial and temporal variation. Based on an accurate channel modeling, analytical expressions of the probability of nonzero secrecy capacity and the outage probability for this type of networks are provided, giving an information-theoretic approach of the problem of secure transmission for satellite networks. The analysis is extended in the case of two legitimate users and two eavesdroppers where the diversity gain increases or decreases, respectively, the probability of secure transmissions. Useful conclusions are drawn concerning the impact of various factors, such as frequency of operation, separation angles and climatic conditions on the aforementioned metrics through extended numerical results.