Model of the battery resource utilization process in the optical line terminal redundant power supply system of the access network

To ensure the specified quality of service (QoS) indicators, reliable power supply of access network elements is necessary. Today, passive optical access networks (PON, Passive Optical Networks) have become widespread as access networks. In PON networks with active elements requiring power supply include the use of OLT (Optical Line Terminal) and ONU (Optical Network Unit). When the voltage from the power grid disappears on the OLT, all subscribers connected to the OLT are deprived of communication. This makes it necessary to use a backup power supply system using a rechargeable battery, the capacity of which is limited.In this work, the mathematical apparatus of Markov processes is used to determine the reliability characteristics of the backup power supply system. At the same time, expressions are obtained for the operational coefficient of unavailability and the conditional coefficient of unavailability (these parameters were first introduced by the authors), the average time of emergency, the average time of battery use in case of voltage loss from the mains, etc.The material presented in this paper can be useful in assessing the QoS indicators of an access network using OLT backup power supply.