Maintaining the reliability of communication networks while continuing operation of optical cables beyond their warranty period

Currently, an increasing number of fiber-optic communication lines are reaching the end of their predetermined service life, yet the quality indicators of these lines still allow for continued operation. To extend the actual operational life of these lines, it is necessary to conduct high-quality monitoring of both the current status of all components and the dynamics of key indicators. This article proposes a method for addressing the challenge of maintaining communication network reliability while continuing to use optical cables after their warranty period has expired. A study of random values of the attenuation coefficient and polarization mode dispersion of an optical fiber, supported by actual operational data from a network segment, shows high temporal stability in the attenuation coefficient and polarization mode dispersion of optical fiber type G.652. This conclusion allows us to discuss the continued operation of optical cables after the warranty period. To analyze the key aging metric, mathematical models are used that take into account the physical and chemical properties of cables as well as the conditions of their proof-tests. Using an example related to the current state of Russian fiber optic networks, we calculate the number of emergency reserve elements necessary to maintain the reliability of their operation. Practical recommendations for the placement of emergency reserve are also provided.