What is Wavelength Division Multiplexing (WDM)? - Neos Networks

What is WDM (Wavelength Division Multiplexing)?

Wavelength Division Multiplexing

Wavelength Division Multiplexing (WDM) is a technology that increases the bandwidth of existing fibre optic networks. We explain the different types of WDM and how WDM-enabled optical networks can help your business.

What is Wavelength Division Multiplexing (WDM)?

Wavelength Division Multiplexing (WDM) is an optical networking technology that allows you to expand the capacity of optical fibre by adding a multiplexer and a demultiplexer at each end of the fibre.

This enables multiple data streams to be transmitted over different light wavelengths through a single fibre. In this way, you can optimise your network infrastructure without the additional cost of laying more fibre.

What is WDM used for?

Traditionally, WDM technology was used for large networks like national infrastructure due to its complexity and cost. Today, businesses use cost-effective WDM solutions in various networking applications to maximise their bandwidth.

WDM is used in metro access networks, data centres, network service providers, or any enterprise environment that needs high capacity, low latency connectivity.

Types of Wavelength Division Multiplexing

There are two main types of WDM: Coarse Wavelength Division Multiplexing and Dense Wavelength Division Multiplexing.


Coarse Wavelength Division Multiplexing (CWDM) typically uses eight active wavelengths per fibre but can support up to 18 channels or more. It’s generally used for connections across shorter distances and can be more cost-effective than DWDM.

Learn more about CWDM


Dense Wavelength Division Multiplexing (DWDM) uses precision lasers to create up to 88 channels or more per fibre. Typically used in core networks where high capacity is required, DWDM is a good choice for businesses transmitting large data volumes over longer distances.

Learn more about DWDM

WDM and Dark Fibre

If you’re looking to lease Dark Fibre for your business’s network, the cost is usually significant. So taking advantage of WDM technology to maximise your network capacity can help offset some of that cost.

Dark Fibre offers almost limitless capacity, easy scalability, and a dedicated connection for maximum security. However, if you’re looking for a swifter setup, less cost upfront, and a guaranteed service without having to manage it yourself, a Lit Fibre service might be the better choice.

Learn more about Dark Fibre vs Lit Fibre

WDM solutions for your business

Whether you lease Dark Fibre or opt for a managed optical network, WDM is a great way to maximise your existing capacity at minimal cost.

At Neos Networks, we’re helping UK businesses boost their connectivity with DWDM-enabled Optical Wavelengths up to 400Gbps across our nationwide network. If you’re looking to future-proof your connectivity to meet the growing data demands of AI, 5G and IoT, get in touch.


We’ll be happy to help you supercharge your network for the future.

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