Advancements in Predicting Failures in Optical Fibers
A recent study has demonstrated the effectiveness of utilizing a coherent transceiver prototype to identify changes in polarization that forewarned a cable break within an operational network. This groundbreaking development, marking one of the initial field-based assessments of an active cable break, highlights the promise of transceiver-based sensing in proactively monitoring and enhancing the resilience of fiber networks.
Enhancing Network Resilience Through Innovative Technology
Employing the expansive fiber network as a sensor could enhance the robustness and dependability of networks by furnishing real-time data to network management and control systems concerning the conditions surrounding each fiber path or link. Upon detecting significant alterations, preemptive actions could be taken to reroute information or issue early alerts to avert network disruptions.
“The significance of safeguarding fiber networks cannot be overstated, given our vulnerability to connectivity disruptions. Thus, safeguarding the fiber network is paramount,” emphasized Mikael Mazur, a member of the Advanced Photonic Research team at Nokia Bell Labs. “Presently, our capacity to address the repercussions of fiber breaks is restricted due to the absence of sensors capable of monitoring the physical surroundings in real-time. Without such sensors, network management is reactive, focusing on addressing issues post-outage rather than proactively preventing them.”
“This applies to all outages, whether triggered by human error during construction or unforeseen events like severe weather conditions. Our findings showcase that coherent transceivers with integrated sensing capabilities can bridge this gap, paving the way for the integration of intelligent fiber networks in the future,” Mazur added.
Research Collaboration and Presentation
The collaboration between Nokia Bell Labs US, Chalmers University of Technology, and Sunet in Sweden culminated in this study. The findings will be presented by Mazur at OFC, a hybrid event scheduled for March 24–28, 2024, at the San Diego Convention Center.
During the research, coherent receiver monitoring was employed to retrospectively analyze data collected in a live network following a fiber break caused by an excavator inadvertently exposing the fiber cable during construction. The 524-km link encompassed five reconfigurable optical add-drop multiplexers (ROADMs) and predominantly featured aerial fiber. The break transpired on a buried segment connecting the ROADM nodes to power line locations.
Monitoring the fiber involved transmitting a co-propagating signal from a field programmable gate array (FPGA)-based coherent transceiver prototype through the active coherent data channels on the network. Initial measurements indicated that most polarization alterations tended to occur at frequencies around 1 Hz,