What is DWDM?

Dense wavelength-division multiplexing (DWDM) is an optical fiber multiplexing technology that increases the bandwidth of fiber networks. DWDM combines data signals from sources over a single pair of optical fibers and it maintains separation of the data streams.  A separate light wavelength carries each signal.  The IETF states that: “A network slice is programmable and has the ability to expose its capabilities”. DWDM systems can support up to 80 channels or more, each with a different wavelength of light, which can then be used to transmit data, voice, and video signals over long distances without the need for regenerating or amplifying the signals. This makes DWDM an ideal solution for high-speed data communication over long distances, such as in telecommunications and internet service providers.

DWDM Basics Slides

DWDM Basics


How does Dense Wavelength-Division Multiplexing (DWDM) work?

DWDM works by using lasers to generate light signals of different wavelengths, which are then combined and sent over a single fiber. The receiver at the other end of the fiber separates the different wavelengths using a demultiplexer, allowing the original signals to be retrieved. DWDM systems can also use amplifiers to boost the strength of the signals, allowing them to be transmitted over even longer distances without losing clarity or quality. Coarse Wavelength Division Multiplexing (CWDM) is another viable options when trying to solve customers' growing bandwidth needs.

What is CWDM?

Coarse Wavelength Division Multiplexing (CWDM) is a simpler and cost effective technology that uses fewer wavelengths of light to transmit data over shorter distances. CWDM is suitable for applications where the distance between the endpoints is less than 80 km, and the data transmission rates are lower, typically less than 10 Gbps. Looking to learn more? Take a deep dive with our CWDM vs DWDM blog or download the IP over DWDM Whitepaper.

IP over DWDM Whitepaper