Design and performance evaluation of a GPON-based fiber-to-the-campus network: a case study of the University of Kufa/Faculty of Engineering

Abstract Campus-wide broadband infrastructure increasingly requires optical access solutions that overcome the distance, capacity, and interference limitations of copper-based digital subscriber lines, yet comparatively few studies evaluate a GPON-based architecture on a university campus using real, surveyed building geometry and a controlled comparison of candidate optical-fiber types. This study designs and simulates a GPON-based fiber-to-the-campus (FTTCampus) network connecting the eight departmental buildings of the Faculty of Engineering, University of Kufa, Iraq, to a single optical line terminal (OLT) through a 1 × 8 passive splitter, with drop-fiber distances (0.095–0.27 km) obtained from Google Earth site imagery. The topology was modeled in OptiSystem at a bit rate of 1 Gbit/s for three candidate fiber configurations, single-mode step-index, multimode step-index, and multimode graded-index, evaluated through eye-diagram analysis, quality factor (Q-factor), and bit-error rate (BER), and the optical link budget of every department link was reconstructed to explicitly include the 1 × 8 splitter insertion loss. The single-mode step-index configuration achieved the highest signal quality (Q-factor up to 136.2), clearly outperforming both multimode configurations. With the splitter loss included, every department link remained functional, retaining an available margin of approximately 15.7–15.8 dB after an 8 dB engineering design margin. These results indicate that a GPON-based FTTCampus architecture is a technically feasible option for university-scale optical access networks.