Lexicon - W

WAN
Wide area network

Wavelength
A measure of the colour of light, usually expressed in nanometers (nm) or microns (*m)

Wavelength division multiplex
Simultaneous transmission of several signals in an optical waveguide at differing wavelengths.

WDM/DWDM
(Dense Wavelength Division Multiplexing) A technique of sending signals of several different wavelengths of light into the fiber simultaneously.