What is DWDM?

Fiber optics run the world. They’re deeply embedded in all of our communications at an infrastructural level. More than that, fiber optics consistently become more available and affordable for all aspects of networking. When you have to ensure the integrity of any network, you want to be certain you’re using the right tools for the job. The only way to gain that certainty is to have a deep understanding of what is available. Today, you can improve that understanding by learning about DWDM technology. It’s a vital form of fiber optic communications that is completely irreplaceable in many applications.


Dense wavelength division multiplexing (DWDM) is a breed of fiber optics that is specifically geared towards extremely data-intense operations. Meeting those data-intense needs is primarily accomplished through two facets of DWDM design.


For starters, this is multiplexed fiber optics. That means the cables are paired in a way that allows data to stream in two directions at the same time. In other words, any node on the network can send and receive information simultaneously.


Perhaps more important to defining DWDM is the nature of the dense wavelengths. A single cable can simultaneously run up to 192 (96 on older designs) distinct communication channels at once. Since each channel can carry up to 100 Gbps, this leads to an aggregate bandwidth of 19.2 Tbps.


DWDM creates this reality by using extremely tight wavelength spacing for each channel. Typical designs are built on either 0.4 nm or 0.8 nm spacing. Since each channel is secured to prevent cross-channel noise and interference, DWDM communications rely on precise laser signaling. This drives up the cost of producing DWDM systems.

How Does DWDM Compare to CWDM?

The other big player in multiplex fiber optics is CWDM. The C refers to a coarse wavelength spacing. This limits CWDM cables to a maximum of 10 Gbps, and enables the designs to use less-precise equipment. In short, CWDM has lower data capacities and costs less money. Choosing between the two will always be determined by the function of the network. There’s little reason to pay for DWDM capabilities unless they’re needed.

What Are Common Applications for DWDM?

Considering the extraordinary data density that DWDM can transmit, it is mostly used in applications that require it. The most common of these applications is telecommunications. Internet providers typically run DWDM in communication hubs.


Similarly, dense data centers often run on DWDM. While the aggregate data rates are important, the ability to run separate data formats and rates on each channel tremendously helps data centers streamline their networks.


Cloud service providers are the other big user of DWDM. As you might imagine, enterprise cloud providers require the extraordinary bandwidth provided by dense fiber optics to meet demand.


In summary, DWDM is one of a large number of means to build a network. It offers some of the fastest data rates available today, and DWDM systems are integral to networking infrastructure. Understanding how it works, its capacity and its applications can help you better determine when and where you should consider DWDM systems of your own. If you need the level of capacity offered by dense wavelengths, you won’t have many alternative options.