This part of IEC 62343, which is a technical report, describes optical channel monitor modules, one of several important classes of dynamic modules that are used in dynamic optical networks. This report includes a description of the necessity of optical channel monitors, specifically in the context of dynamic optical networks, and how this is driving feature and performance requirements. This technical report surveys the different categories of optical channel monitor technologies that are being used and highlights some of their unique characteristics. Also described are different possible approaches for characterizing and specifying the performance of optical channel monitor modules.