Executive summary Optical fibre networks have long been the backbone of global digital communication transmitting massive volumes of data at the speed of light across continents and oceans. Yet beyond their primary role as high-capacity data conduits, these same networks hold untapped potential as multifunctional sensing systems capable of monitoring the physical world in real time. By leveraging the natural light-scattering and reflection properties of optical fibres, operators can transform existing infrastructure into a powerful network of sensors, detecting vibrations, temperature changes, and environmental anomalies without disrupting data transmission. This evolution redefines fibre networks not merely as digital pipelines, but as intelligent sensory layers for infrastructure, environmental monitoring, and public safety. The core function, high-capacity data transmission Optical fibre remains unmatched in its ability to deliver high-speed, high-bandwidth connectivity across long distances with minimal signal loss. As digital demand continues to surge driven by 5G, AI, and IoT expansion, these...