Wave Division Multiplexing (WDM)

A means of multiplexing different wavelengths of light onto the same physical fiber-optic communications line pair, allowing up to a 40x increase in bandwidth. A single wavelength of light limits a T1 line to 1.4 Mb/s (+/- allowing for clocking); using different wavelengths of light allow the same fiber pair to carry 60Mb/s of data.