5.3 Wave Division Multiplexing
Wave or Wavelength Division Multiplexing (WDM) is used with fibre optic cables. WDM is a technology that closely resembles frequency division multiplexing, but is specifically used to combine lots of Optical Carrier signals into a single optical fibre.
The WDM technique relies on a laser that is designed to emit single colours of light. Each of the signals that is to be transmitted is then attached to a laser that will emit a different coloured light beam. All these individual light beams are then sent at the same time. At the receiving end, a device splits the combined colours back into the original individual colours again.
Code Division Multiplexing
Next: 5.4 Line Sharing