Multiple Fiber Fault Location With Low-Frequency Sub-Carrier Tone Sweep
We present a monitoring technique that can be directly integrated in the sub-carrier multiplexing (SCM) transceiver for PtP and wavelength division multiplexing and sub-carrier multiplexing passive optical networks applications. The technique is based on the detection of the backscattered signal from a baseband tone (100 Hz to 100 kHz) and interpretation with the least absolute shrinkage and selection operator (LASSO) operator, a signal processing technique which identifies the fault positions based on the mathematical model of the received signal. The proposed single-ended fiber probing method enables the location of multiple faults with no a-priori knowledge of the fiber, and offers low-cost in-service operation with negligible impact on data transmission, few meters spatial resolution, and limited dynamic range. Due to all its advantages, but also considering its reach limitation, the SincLASSO method features as an ideal monitoring candidate for short reach sub-carrier multiplexed optical fiber networks, such as the ones intended for analog mobile Fronthaul based on fiber and fiber-extended copper lines.