Integrated Fiber Sensing and Communication for Optical Networks: Principles, Solutions, and Challenges

The integration of optical-network sensing and communication (optical-network ISAC) can effectively utilize resources and meet the demands of intelligent scenarios, becoming a future development trend. This article reviews the fundamental technical principles involved in the optical-network ISAC, including three types of backward-sensing based on Rayleigh scattering, Raman scattering, and Brillouin scattering, respectively. The forward-sensing methods based on power profile estimation (PPE) and the state of polarization (SOP), as well as bidirectional sensing, are compared and analyzed. The technical difficulties and recent solutions to realize the optical-network ISAC are introduced, including the existing solutions implemented at the transmitter side or the receiver side. Finally, we discuss the new opportunities and major challenges of the optical-network ISAC technique for practical applications.