Analysis of reliability indicаtors special communication systems

The analysis and the classification of indicators of quantitative evaluation of reliability of a special communication system using the systemic approach in their study are proposed. The features of element and structural reliability of special communication systems were considered. It is shown that they belong to complex technical systems. Therefore, to determine and study their reliability indicators, simulation and systemic approach should be used. Analysis of the composition of the special communication system and interaction between its elements shows that the reliability property, which lies in the ability to provide communication with preservation in time of performance indicators values, established by specifications and technical documentation, is supported by technical communication support subsystem with the performance of all types of repair, maintenance and provision with operational materials and consumables.Traditionally, the availability factor, which is the serviceability probability of all system elements and the availability of all communication directions for the full operation, is used as the main reliability indicator of the special communication system. However, for special communication systems with more objective characteristic there is the probability of system availability to transfer information between subscribers (communication nodes) at least in one communication direction that in the literature on reliability theory is called the connectivity probability or serviceability probability of at least one of the possible communication directions.The paper shows that the availability factor is less than serviceability probability. The equality occurs if each element of the special communication system is used only in one direction and only once without other communication directions.