Wavelength division multiplexing (WDM) techniques help expand the capacity of your network and solve many complex communications problems. Advanced Circuit Manager functionality, introduced with Fiber Manager 10.2.1a, allows you to create circuits in your Fiber Manager network specific to a particular wavelength, and to include fiber objects in as many circuits as necessary to represent the multiple logical paths that result from implementing wavelength division multiplexing.
Consider this example of a network issue solved by utilizing WDM: From a hub site, a signal can be sent downstream on a certain wavelength, such as 1310 nm. That signal feeds several nodes and travels through several different splitters. The node can then send return traffic on different wavelengths that get muxed onto a single fiber. The signal travels upstream to the hub site to get demuxed to different receivers that are configured for the appropriate wavelengths.
Changes to the Fiber data model have been made to accommodate WDM functionality. In the past components like splitters and muxes were their own features in the map. They have now become nested features inside of other structures like splice enclosures, pedestals, and patch locations. An example of changes to the data model involves viewing a splice enclosure in ArcMap's Attribute Editor. Inside of the splice enclosure are related objects, such as add muxes and drop muxes, depending on how you want your network to be configured. The muxes have multiple input ports that support given wavelengths and/or minimum and maximum wavelengths for capturing a range of wavelengths.