As online traffic continues to explode, network engineers must find ways to squeeze more bandwidth from existing infrastructure. Optical fiber cables form the high-speed backbone for global communication networks. But how can we meet demand when we‘ve nearly maxed out capacity on buried fiber links?
The answer lies in sophisticated wavelength multiplexing technologies that combine multiple signals across different colors of laser light. If you are involved in network design, it‘s important to understand these transport methods. Let‘s demystify two common types – CWDM and DWDM.
A Brief History of Wavelength Division Multiplexing
WDM originated in the 1980‘s by combining four fiber pairs into one. This evolved into Dense WDM (DWDM) in the mid 90‘s by packing channels closer together. A less complex version called Coarse WDM (CWDM) emerged for shorter distance networks. Today, 100G+ DWDM lines form the ultra-high capacity global network backbone.
As online activity grows exponentially, overall IP traffic is projected to more than double in the next 4 years. Video streaming accounts for most bandwidth use, but emerging technologies like AI, blockchain, 5G, and IoT promise continued massive growth.
How Fiber Optic Communications Work
If data networks are superhighways, fiber optic cables are the ultimate roadway. Glass fiber strands transmit beams of light rather than electronic signals, so fiber can handle vastly greater bandwidth over longer distances.
Lasers inject modulated light beams representing 1‘s and 0‘s into the cable core. The pulses bounce between mirror-like walls due to a process called total internal reflection. After miles of travel, photodiodes convert the photons back into data.
Overview of Wavelength Division Multiplexing
WDM enables multiple signals to share the same fiber simultaneously by using different laser light colors, or wavelengths. You can visualize the cable as a multilane expressway. Each vehicle transmits independently by staying in its lane, defined by wavelength rather than road markings.
Traffic capacity grows by minimizing lane spacing or adding more lanes (colors). Imagine reducing spaces from meters in a normal highway to nanometers for light beams! Advanced modulation techniques like polarization further multiply capacity.
Coarse Wavelength Division Multiplexing Explained
Coarse WDM provides a simpler, lower cost way to add capacity than DWDM…
