Urban Monitoring Using Pre-Existing Telecommunication Fiber-Optic Networks as Distributed Acoustic Sensing Systems: A Review

Urban monitoring is important for maintaining safe and sustainable urban life through infrastructure assessment, resource optimization, and public safety enhancement. Vibration and seismic signals offer rich insights into urban environments, reflecting both physical and environmental conditions and societal activities. Recent advancements in Distributed Acoustic Sensing (DAS) have leveraged pre-existing telecommunication (telecom) fiber-optic networks as dense arrays of seismic and vibration sensors, providing a scalable, cost-effective, and continuous urban monitoring solution. DAS technology uses internal imperfections in fiber-optic cables to measure dynamic strain (rate), enabling fibers to capture seismic waves and structural vibrations at meter-scale intervals over tens of kilometers. By utilizing pre-existing telecom fiber networks as urban-scale sensing platforms, DAS has demonstrated broad applications ranging from seismic monitoring and subsurface imaging to urban activity detection and structural health assessment. As research and technological advancements continue, DAS is positioned to become prominent in next-generation urban sensing, supporting smarter, more resilient, and more sustainable urban planning and development. Building on these developments, this paper reviews the latest progress in urban monitoring using pre-existing telecom fiber networks as DAS systems.