Difference between CWDM and DWDM
This page describes on CWDM vs DWDM describes difference between CWDM and DWDM fiber optic technologies.
The figure-1 depicts CWDM based fiber system. As shown it is used to transmit 4 different applications using single optical finer instead of pair of fiber cables. Different applications are using different light wavelengths which helps in multiplexing and de-multiplexing applications at transmit and receive end.
DWDM-Dense Wavelength Division Multiplexing
The figure-2 depicts DWDM system consisting of transmitter and receiver parts. Typically DWDM consists of MUX, DEMUX, isolators, circulators, EDFA (Erbium Doped Fiber Amplifier) etc.
DWDM system basics
|Coarse Wavelength Division Multiplexing,WDM system having less than 8 active wavelengths per optical fiber
|Dense Wavelength Division Multiplexing, WDM system having more than 8 active wavelengths per optical fiber
|Defined by wavelengths
|Defined by frequencies
|short range communication
|long range communication
|uses wide range frequencies
|uses narrow range frequencies
|less, hence can pack 40+ channels compare to CWDM in the same frequency range
|light signal is not amplified here
|light signal amplification can be used here
|Wavelength drift is possible
|Precision lasers are needed to keep channels on the target
|Breaks the spectrum into big chunks
|dices the spectrum into small pieces
|No. of active wavelengths per fiber
|Fewer than 8
|More than 8