An Overview on Performance Monitoring in Optical Networks

Next generation optical networks will evolve from static to dynamically reconfigurable architectures to meet the increasing bandwidth and service requirements. When considering signal quality in static networks, it is sufficient to monitor a single channel in a WDM system, since all channels travel through the same fixed path degrading the signal quality uniformly due to link mismatch. However, in dynamic networks, each channel will traverse a unique path through the network thus the channels arriving at the monitoring point will, in general, exhibit different quality signals. Therefore, in a dynamic network it is necessary to monitor all channels individually to quantify the degradation, without the requirement of knowing the data path history. Thus optical performance monitoring (OPM) is essential in building a reliable, high-capacity, and service-differentiation enabled all optical network.