Setting and Checking Availability Requirements for Communication Networks and Systems

Dependability requirements are increasing with each new generation of communication networks and systems. Availability is one of the core dependability attributes and dependability requirements are often set as requirements specifically for availability. Therefore, it is very important correctly specify such requirements and validate compliance with them. These issues are studied in this paper. A parametric approach with a time over threshold is proposed to determine failure and restoration criteria. The choice of availability measures for communication networks is considered. The features and difficulties of applying the calculation method and tests to validate compliance with requirements at the design and commissioning stages are discussed.