ITU-T OTN [Guest Editorial]

Fiber optic cables form the basis of almost all terrestrial communications networks today. Even mobile phone calls and television signals are carried over fiber optic cables as they traverse the path they must travel from source to destination. Currently deployed systems carry highly aggregated data streams of up to 40 Gb/s with test systems already trialing 100 Gb/s streams. Wavelength-division multiplexing (WDM) technology already supports 100 or more of those high-bit-rate data streams (channels) on a single fiber. The massive data capacity of fiber optical cables is one of the reasons for its popularity in communications networks.