The integration of long-haul high-speed optical communication and distributed sensing within a single optical fiber represents a crucial step toward more efficient and scalable infrastructure for real-time environmental observation and data delivery. This study examines the performance of a 120 km single-mode optical link operating at 10 Gbps, embedded with three fiber Bragg grating (FBG) sensors positioned at 30 km intervals, enabling dual functionality over a shared single strand of physical medium. A broadband amplified spontaneous emission (ASE) source is employed to simultaneously provide the 1550 nm data channel and interrogation wavelengths at 1554, 1556, and 1558 nm for the FBG sensors. System performance is assessed using standard optical communication metrics, i.e., Q-factor, bit error rate (BER), and eye diagram analysis, while sensor reliability is evaluated through reflected signal levels and wavelength shifts captured at the receiver. The results demonstrate that sensor integration introduces no significant degradation in the transmission quality. The proposed system maintained robust performance, achieving a Q-factor of 6.38 and a BER of 6.23 × 10−11 under post compensation configuration of the dispersion compensating fiber (DCF). All FBG reflection signals remain clearly distinguishable and maintain effective responsiveness to temperature variations, confirming the feasibility of concurrent distributed sensing. By unifying sensing and high-speed communication in a long-haul link, this work thereby minimizing component count, cost, and complexity, establishing a practical foundation for next-generation scientific monitoring and reliable telecommunications (SMART) infrastructure. © 2025 Faculty of Engineering, Universitas Indonesia. All rights reserved.