DWDM is a means of increasing the capacity of fiber-optic transmission systems through the multiplexing of multiple wavelengths of light. It takes advantage of the large bandwidth of optical fiber by optically combining laser light signals of various wavelengths, and transmitting the resulting composite signal over a single fiber. It therefore does away with expensive conversion of optical signal to electrical one and vice versa. Optical networking also offers services at much higher speeds than current networks. A network that is transparent means there is less conversion from optical signals to electrical signals and vice versa.
Pure transparency means there is no conversion at all.
Thanks to redundancy, the receiving device can detect and correct multiple bit-errors that may occur during transmission. The signal transmitted with FEC is more robust , thus allowing operators to build up longer distance connections without the deployment of many repeater stations. All rights reserved Copyright 2000 Compagnie Financi re Alcatel, Paris, France.