Computer Generated Optical Time Domain Reflectometry (OTDR) Traces for Remote Monitoring of Passive Optical Networks

Scriptie/masterproef: Master's Thesis


The potential growth of telecommunication traffic with 90% per year makes present-day service providers to remove copper cables from the last miles in telecom networks and shift towards Passive all-Optical Networks (PON) for broadband access. To respect the subscriber's requirements for high-quality service, a PON demands a reliable monitoring system for the identification, localization, and loss quantification of existing faults in the network. The challenging problem, which network providers encounter today, is that Optical Time Domain Reflectometry (OTDR), which is generally used to test faults, is an inappropriate monitoring method in a PON because it requires expensive truck rolls. The aim of this work is to look at the possibilities for remote monitoring, enabling OTDR measurements from the central office. Remote monitoring based on timing signatures would allow to filter out the discrete Rayleigh reflections form only one of the splitter branches. As such, this would make it possible to locate discrete events such as connectors, non-ideal splices and even fiber breakage along the fiber behind a splitter.
To test the capabilities and, more importantly, the limitations of such a method requires the generation of detailed OTDR traces of typical PON networks. To this end, we have generated such OTDR traces of PON network lay-outs via computer simulations. Additionally, limitations of current OTDR equipment such as a limited dynamic range, dead zone and noise floor, are introduced into the simulator in order to come to realistic results. Finally, we have also used our code to check whether fiber Bragg gratings (FBGs) can be used as reflective elements to generate timing signatures of the different branches of a PON, to enable remote monitoring from the central office.
Datum Prijsjan 2012
BegeleiderMichael Vervaeke (Promotor) & J├╝rgen Van Erps (Co-promotor)

Citeer dit