Continued… DWDM Part V – Capabilities & Merits and Limitations

Today, I’ll continue sharing the info on other four aspects of DWDM capabilities and merits (brief info). Yesterday, I’ve shared on “Extendibles” aspect.

  • Reliable:

Tunable lasers, used in DWDM technology, eliminate adjacent channel interference and optimize DWDM performance.

  • Flexible:

Tunable lasers, used in DWDM technology, also allow service providers to adapt to capacity changes by automatically adding or dropping channels or wavelengths in response to application requirements. Service providers can benefit from a DWDM infrastructure by partitioning and maintaining different dedicated wavelengths for different customers. For example, service providers can lease individual wavelength as opposed to an entire fiber to their high-use business customers.

  • Scalable:

The number wavelengths and bit rate can be upgraded for all DWDM systems, however planning for this is critical. If service providers put together their networks in a specific way and then want to upgrade, one of two things must happen:- they need either more power or additional signal-to-noise margin.

  • Available:

DWDM technology supports variety of optical interfaces; works with many other technologies such as SONET/SDH, ATM, IP, WDM, and Gigabit Ethernet.

I’ve shared above the capabilities and merits of DWDM, which look promising.  How about its limitations? Any technology typically has its limitations. Check it out below!


  • DWDM standards are ‘may ‘not yet fully specified. As a result, DWDM networks generally use proprietary management and multiplexing procedures.
  • DWDM service is adversely affected by sudden temperature changes in optical-cross connects and manufacturing imperfections in the fiber optic plant.
  • Signal attenuation, optical signal-to-noise ratio (OSNR), chromatic dispersion, and crosstalk at the Optical Layer also disrupt DWDM network performance.
  • DWDM-based equipment such as precision filters, optical amplifiers, cooled lasers, and routers are new, cutting-edge patented, which can make DWDM too expensive for some small to mid-sized companies. – In the initial phase of implementation, DWDM systems typically work with existing SONET/SDH-based equipment, SONET/SDH applications, and employ the in-place fiber optic plant for long-haul optical network transmission.
  • DWDM transmits multiple wavelengths or channels over a single fiber. As more channels are being multiplexed, data rates on a single channel and the complexity also increase. – More research is needed to understand how to utilize the huge bandwidth capacity of a DWDM system quickly and cost-effectively – how many DWDM channels and how high a data rate of each channel can be utilized.

These limitations probably have been overcome by the researchers or technologists. So, please accept my apology.

Source: DWDM: Technologies and Initiatives by Khoa Duc Tran

To be continued… DWDM Part VI


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