Real-time monitoring system for ethernet passive optical access network

Numerous research studies on fiber fault monitoring have been conducted. However, current approaches are difficult to be implemented due to their complexity, high loss value as the number of branches increase. This paper presents a simple, robust and efficient technique to monitor fiber fault in Passive Optical Network (PON) for tree-structured network using fiber Bragg grating (FBG). A distributed feedback (DFB) laser with high side lobes are used as the monitoring signals. The wavelength of the reflection spectrum of fiber Bragg gratings (FBGs) with different spectrum shape and amplitude are used to differentiate each distribution fibers in the network. The simulation result shows that the unique characteristics of fiber Bragg grating is able to distinguish six fibers connected to Optical Network Units (ONUs) for a 20 km Ethernet Passive Optical Network (PON) system. From the power budget calculation, it is found that up to 32 customers can be monitored in this network.