Reliability analysis of underground fiber optic infrastructure in Rural Areas: Case Study of the Matadi-Boma Section, Kongo Central Province, DRC

The reliability of fiber optic infrastructure is crucial for ensuring the continuity of digital services, particularly in rural areas of developing countries where environmental and operational challenges are significant. This study presents a reliability analysis of the underground fiber optic cable on the Matadi-Boma section of the national backbone in the Kongo Central province of the Democratic Republic of Congo. A mixed-method approach was employed, combining field observations, analysis of maintenance data from 2022 to 2025, and probabilistic modeling using both statistical (Exponential and Weibull) and stochastic (Markov chains) approaches. The field survey revealed that external factors specifically civil engineering works, erosion, and vandalism are the primary causes of cable cuts. Data analysis showed a direct correlation between the frequency of repairs (splicing) and increased optical losses, with a maximum splice loss of 3.94 dBm recorded in 2023. The developed Markov model with five degradation states effectively captured the progressive degradation of the optical fiber over time. The results confirm that a combined probabilistic approach provides a robust framework for assessing network reliability and optimizing maintenance strategies, thereby enhancing the resilience and durability of optical infrastructures in similar rural contexts.