On the Effect of Sudden Failures and Control Errors of the First Kind on the Degradation Cycle of an Optical Cable

The failure of the access network fiber leads to failures on a variety of channels and the loss of a huge amount of information. Therefore, increased requirements are placed on the reliability of fiber-optic lines. Failures of an optical cable can be divided into sudden and degradation failures that occur due to the aging of the optical fiber during operation. To determine the presence of fiber failures, a technical condition monitoring system can be used, that performs periodic monitoring, as a result sudden failures are detected. At the same time, false alarms are possible when the system records a failure in its actual absence, i.e. control errors occur. The article discusses the impact of sudden failures and control errors of the first kind on the optical cable reliability in the conditions of its degradation during operation. To solve this problem, a Markov reliability model was developed. On its basis equations for calculating the unavailability factor, the average recovery time on the degradation cycle, and the average degradation cycle duration of an optical cable under periodic monitoring conditions were obtained. It is shown that the unavailability factor of the optical cable is influenced by the duration of the intervals between checks and control errors of the first kind. The optical cable reliability model presented in the article can be useful for predicting the operating time of an optical cable.