Do you know The difference between CWDM transceiver and DWDM transceiver?

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DWDM
technology multiplexes the tight spectral spacing of a single optical fiber
carrier in a given fiber to take advantage of the transmission performance that
can be achieved. DWDM wavelength spacing is very tight, because the closer the
spacing is, the more channels per fiber will be reused, and thus the higher the
bandwidth. The international telecommunication union (ITU) g. 694.1 standard regulates
the nominal wavelength interval of DWDM system. Each channel was spaced three
ways: 0.4nm(50Ghz), 0.8nm(100Ghz), and 1.6nm(200Ghz).

 

The
most important advantage of CWDM is the low cost of equipment. Because of the
wide wavelength interval of CWDM system, the requirement for the technical
index of laser is low, so the structure of laser is greatly simplified and the
yield is improved. In addition, the power consumption and physical size of CWDM
system are much smaller than DWDM system. In addition, CWDM light modulation
adopts non-cooling laser and electronic tuning. DWDM USES a cooling laser and
temperature tuning. Temperature tuning is difficult and expensive to implement
because of the unevenness of temperature distribution over a wide wavelength range.
CWDM avoids this difficulty, thus significantly reducing the cost. Currently,
the cost of CWDM system is generally only 30% of DWDM. As the name implies,
sparse wavelength division multiplexing (RWDM) is a close relative of dense
wavelength division multiplexing (DWDM). There are two main differences between
them. Firstly, CWDM carrier channels are widely spaced. CWDM modulating laser
USES non-cooling laser, while DWDM USES cooling laser. Temperature tuning is
used for cooling laser and electronic tuning is used for non-cooling laser.
Temperature tuning is difficult and expensive to implement because of the
unevenness of temperature distribution over a wide wavelength range.

 

CWDM
avoids this difficulty, because it significantly reduces the cost, the cost of
the whole CWDM system is only 50% of DWDM.CWDM provides a high access bandwidth
at a very low cost and is suitable for point-to-point, Ethernet, SONET ring and
other popular network structures. It is especially suitable for short distance,
high bandwidth and point-intensive communication applications, such as network
communication within or between buildings. CWDM and PON (passive optical network) are particularly worth mentioning.

 

PON
is an inexpensive, point-to-multipoint optical fiber communication method. By
combining with CWDM, every single wavelength channel can be used as a PON
virtual optical link to realize broadband data transmission between the center
node and multiple distribution nodes. What are the differences between thick
wavelength division multiplexer (CWDM) and dense wavelength division
multiplexer (DWDM)? take the fast optical fiber as an example to compare the
main band spacing and band 2 differences.

 

Wavelength
division multiplexing (WDM) refers to the use of laser signal multiplexing to
send multiple beams of different wavelengths simultaneously on a single optical
fiber. Each optical signal has its own wavelength, and they are usually
concentrated in the range of 1500nm to 1600nm, which is called the WDM ribbon.
Optical signals are modulated by data (text, speech, video, etc.) and
transmitted in its own color band. WDM supports existing network bandwidth
expansion without the need to add additional fiber optic cables, and can save
fiber installation costs, significantly reducing the operational capacity costs
of metropolitan and wide area networks. WDM can also implement solutions that
cannot be implemented without increasing the number of optical fibers.

 

First,
on the one hand, FDM is generally used to describe old multiplexing systems
that process electrical signals, while WDM refers to newer multiplexing systems
that process optical signals.

 

Secondly,
on the other hand, in the FDM system, each frequency multiplexing represents
the multiplexing of models from a single transmitting source, while one of the
main applications of WDM is the multiplexing of optical fiber synchronous
network (SONET) signals. Each SONET
signal can transmit multiple signals from multiple sources through time
division multiplexing (TDM) technology. Therefore, in the application of
timing, WDM technology will generally combine TDM and FDM technologies to
achieve higher bandwidth utilization.