Dense Wavelength Division Multiplexing or DWDM is still a preferred choice for many telecom engineers. However, the high cost of DWDM works as a major deterrent for many fiber optic technicians and operators. However, there’s a low-cost alternative to DWDM and it is CWDM or Coarse Wavelength Division Multiplexing. CWDM is now being used by many operators all across particularly because of its considerably low cost.
The key differences
Leaving aside the cost differences, CWDM and DWM have at least two other major differences. First off, the carrier spacing in CWDM is wider. This is why light passing through a fiber can re-use five or six wavelengths. The coarse and dense appellations come from these wavelengths. Secondly, CWDM modulation laser is used for un-cooling laser, and DWD laser is used for cooling laser. While cooling laser uses temperature-tuning, un-cooled laser uses electronic tuning. Due to the temperature distribution non-uniformity, it’s quite difficult to realize the temperature differences. CWDM rightly resolves this issue and costs less than one third of DWDM.
The CWDM advantages
CWDM offers a high-access bandwidth for a low cost. CWDM is suitable for point-to-point transmission. There are various kinds of popular network structures that are suitable for short-distance communication applications that are access point-intensive as well.
For example, for build to building network communication, CWDM uses Passive Optical Network or PON. This type of network is indeed is a very inexpensive point-to-point fiber communication mode that can be paired with CWDM for using each wavelength channel as a virtual optic network. Effectuation of broadband transmission can be done using this combination between a centralized node and multiple nodes distributed.
The DWDM edge
Though there are quite a few companies that are offering CWDM modules at this moment (and we are also one of them), there’s a trade-off between performance and price. You will also find some limitations in CWDM products. CWDM is a single-fiber support WDM, which leads to high extension costs later on.
One major advantage of DWDM is that it is protocol independent and also bit-rate independent. Considering the long-term cost advantages, DWDM is a better alternative to CWDM. It can carry varied bytes of traffic at variable speeds over optical networks. It can transmit data in ATM, Ethernet, SONET/SDH and in IP.
If you want to know more about DWDM components, please send us a sales inquiry and we can send you back with full product literature.