Enhanced fault characterization by using a conventional OTDR and DSP techniques

Abstract

To plan a rapid response and minimize operational costs, passive optical network operators require to automatically detect and identify faults that may occur in the optical distribution network. In this work, we present DSP-Enhanced OTDR, a novel methodology for remote fault analysis based on conventional optical time-domain reflectometry complemented with reference traces and DSP-based techniques. We first obtain the optimal decision thresholds to detect deviations in the noisy OTDR measurement. In order to quantify and characterize the fault, the detection stage is followed by one of estimation where its return loss and insertion loss are determined. We experimentally demonstrate that this approach allows to detect and characterize faults with an accuracy higher than that found in conventional OTDR trace analysis. In our experiments, we achieved detection sensitivities higher than 0.2 dB in a 1:16 split-ratio PON, and higher than 1 dB in a 1:64 split-ratio PON, achieving estimation errors that can be as low as 0.01 dB. We also verified how the optical network terminal's reflectivity can improve the detection capabilities.

Adopting Intelligent Modelling to Trace Fault in Underground Optical Network: A Comprehensive Survey

“…The OTDR has been deployed in fault tracing (Mas et al, 2005;Fernández et al, 2018) and assessing splice loss in optical network infrastructure. The device has also been used in most cases to establish the integrity of FOC when it is newly installed (Caballero et al, 2012).…”

“…The fault is caused by a change in reverse coefficient elements such as air gap or severe particles obstructing the free flow of the light signal (Kovacevic et al, 2018). However, by using the information of Fresnel reflection, the OTDR can measure the distance from the optical transmitter to the location of faults (Fernández et al, 2018;Wilson, 2012).…”

Predicting the actual location of faults in underground optical networks using linear regression

“…Many solutions, especially the use of OTDR for determining the precise length of fiber cable cuts in underground optical transmission systems, have been developed 10,11 and the application of ML to trace faults in soft and hard failures of optical transmission infrastructures 12,13 . Thus, telecommunication companies have, over the years, relied on OTDR due to its preciseness in estimating the distance of fault in fiber cables.…”

Silicon nitride polarisation beam splitters: a review

“…The development of photonics systems and circuits with applications in optical communication networks [1–4], photonics signal processing [5–8] and measurements/instrumentation [9, 10] have become a very important discipline because of the implicit advantages of photonics with respect to electronic counterparts, such as broad bandwidth, low attenuation, light weight and the immunity to electromagnetic interferences.…”