Coarse Wavelength Division Multiplexing (CWDM) is a technology commonly used for enterprise solutions and applications where cost is a priority with less demanding bandwidth and range requirements.
CWDM modules have a wide wavelength span of 20nm between channels, supporting up to 18 within the 1270nm – 1610nm wavelength range (although many implementations use less than this). Although this allows for fewer channels, it reduces the need for precise wavelength control and cooling systems which is big factor in making them cheaper and less power intensive than DWDM modules.
Additionally, CWDM is typically used for shorter range communication of generally up to 80km. This is due to higher levels of attenuation in the system that increases with distance. The types of lasers used for wider wavelength spans do not need to be as precise which causes higher attenuation in the fibre. Additionally, CWDM systems don’t support amplification technologies as they tend to be optimised for specific narrower wavelength bands like those that DWDM systems operate within.
See our Tech Talk post for more information on Wavelength Division Multiplexing (WDM) and how it works. You can find our CWDM Wavelength and Channel guide here.
