Mitigation of the parallel-path effect for reliable monitoring of a passive optical network using standard optical time domain reflectometry

Optical access networks evolve towards higher bit-rates, which is driven by a growing number of fiber-to-the-home users and by bandwidth-demanding mobile transport. Maintenance requirements of such networks call for very effective and efficient supervision of the fiber infrastructure. Moreover, since the fiber is also known for its sensing capabilities, the outside distribution plant of the access network has been recently considered for providing sensing services co-existing with telecom services. To enable reliable fiber monitoring and sensing, the detrimental impact of the parallel-path effect in point-to-multipoint access networks needs to be addressed. This paper introduces the concept of serialization of an optical time domain reflectometry trace of a point-to-multipoint passive optical network, which radically reduces the parallel-path effect impact on fiber anomaly detection and measurement. The concept is experimentally proven in a representative access network architecture.