Difference between DWDM vs.CWDM
What is DWDM? DWDM is a shortening Dense Wavelength Division Multiplexing. DWDM as an optical transmission technology has evolved after the previous SONET/SDH technology has reached its limitations in terms of ecosystem components to achieve price competitive high data rates transmissions over the fibers.
The Development of WDM WDM technology has changed the way that data streams are launched on the fiber. The development of optoelectronic components has allowed transmitting simultaneous parallel light waveguides on the fiber expanding the total bandwidth of a transmission system. Multiple high-bit rate data streams of 2.5 Gb/s, 10 Gb/s and, more recently, 40 Gb/s and 100Gb/s could be multiplexed through divisions of several
wavelengths. And so was born Wavelength Division Multiplexing (WDM).
CWDM / DWDM - The Differences 1.
DWDM uses frequencies standardizations, the ITU-T G.694.1 frequency grid to address each channel.
2.
Analyzing and comparing the signals on the fiber it may be observed the wider band signals of CWDM and larger spaces between lambdas having a greater tolerance to frequency shifting. Multiplexing and demultiplexing of channels can be achieved with components at reasonable prices.transmitted over fiber; these frequencies are much more ‘dense’ and more tightly spaced than CWDM. CWDM uses lambdas to refer to its transmission guides and the ITU standardized a channel spacing grid for use with CWDM (ITU-T G.694.2).
3. DWDM system can reach distances of thousands of kilometers with the combination of Erbium Doped Fibre Amplifier or Raman Amplifiers on single mode fibers. CWDM
distances are up to tens of kilometers without the use of optical amplifiers that may be adequate for metro carriers who prefer to start small and expand later as demand increases.
CWDM Defined by wavelengths Short-range communications Uses wide-range frequencies Wavelengths spread far apart Wavelength drift is possible Breaks the spectrum into big chunks Light signal isn't amplified Entry level price
DWDM Defined by frequencies Long-haul transmissions Narrow frequencies Tightly packed wavelengths Precision lasers required to keep channels on target Dices the spectrum into small pieces Signal amplification may be used Expensive price systems.