Dense Wavelength Division Multiplexing (DWDM)

Dense  wavelength  division  multiplexing  (DWDM)  is  a  technology  that  puts

data from different sources together on an optical fiber, with each signal carried at

the same time on its own separate light wavelength. Using DWDM, up to 80 (and

theoretically more) separate wavelengths or channels of data can be multiplexed into

a  light  stream  transmitted  on  a  single  optical  fiber.  Each  channel  carries  a  time

division multiplexed (TDM) signal. In a system with each channel carrying 2.5 Gbps

(billion  bits  per  second),  up  to  200  billion  bits  can  be  delivered  a  second  by  the

optical fiber. DWDM is also sometimes called wave division multiplexing (WDM).

Since each channel is demultiplexed at the end of the transmission back into

the original source, different data formats being transmitted at different data rates

can be transmitted together. Specifically, Internet (IP) data, Synchronous Optical

Network data (SONET), and asynchronous transfer mode (ATM) data can all be

traveling at the same time within the optical fiber