DWDM (Dense Wave Division Multiplexing) is one of the latest fibreoptic transmission technique
s to be used in the telecom
s industry to attempt to alleviate the problems of fibre exhaust
Based around similar technology found in WDM (Wave Division Multiplexing) it works by combining different light wavelengths to transmit data parallel-by-bit or serial-by-character. This combination is done by assigning incoming optical signals to specific frequencies within a designated frequency band and then multiplexing the resulting signals out onto one fibre. This has the potential to massively increase the capacity of current fibres that use TDM, as rather than using a single wavelength down the fibre multiple wavelengths are used. Current DWDM multiplexers can handle 160 separate wavelengths running at 10Gbit/s, allowing over 1.6Tbit/s down one fibre, but these figures should increase massively as the current gaps between wavelegths is around 0.1 nm.