What stands for xWDM – basics to our CWDM & DWDM systems

The IT refers to a medium where information are transmitted via a line. When two applications would like to communicate together, one line is sufficient. More lines are needed for more applications.
What if only one line e.g. between two cities is available, but more applications shall be connected? Using the xWDM technology, fiber optic lines can be utilized for data transmission more efficiently.

The idea of xWDM technology
Each application is allocated to a dedicated color (wavelength) for communicating with a remote station. The advantage is that different colors can be simultaneously transmitted using one pair of fibers. For this purpose a multiplexer combines all different colors which will then be transmitted to the remote station in a single fiber optic cable. At the remote site the cable is separated back into different colors by a demultiplexer.
Generally only one light beam with one wavelength is transferred over a pair of fibers. The wavelength multiplexing technology provides the ability to transmit more light beams, each having different wavelengths, using the same optical line. Due to the fact that wavelengths do not superimpose, single light beams can be separated from each other using simple filter. A laser or a light-emitting diode serves as a source of light. Wavelength multiplexing is differentiated in CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) technology.