Optical Network Design and Implementation

Dense Wavelength-Division Multiplexing

Dense wavelength-division multiplexing (DWDM) is a method to insert multiple channels or wavelengths over a single optical fiber. DWDM maximizes the use of the installed fiber base and allows new services to be quickly and easily provisioned over the existing fiber infrastructure. DWDM offers bandwidth multiplication for carriers over the same fiber pair. DWDM alleviates unnecessary fiber build-out in congested conduits and provides a scalable upgrade path for bandwidth needs.

As illustrated in Figure 1-5, various wavelengths are multiplexed over the fiber. End or intermediate DWDM devices perform amplification, reshaping, and timing (3R) functions. Individual wavelengths or channels can be dropped or inserted ...