Coarse Wavelength Division Multiplexing (CWDM) Key Features: Uses uncooled lasers, significantly lower cost per channel, simpler design, lower power consumption. Applications: Short to medium reach (up to 80km), cost-sensitive metro access, enterprise networks, point-to-point. In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i. Learn all about CWDM, how it differs from DWDM, and whether a CWDM solution is right for your business's network. The main purpose of WDM is to increase the available bandwidth.