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 or dense WDM can have up to 128 channels with 37.5GHz spacing of each channel. Those channels can be up to 400G or greater but may need wider spacing depending on how far you want to go. While at the same time they can be amplified for long distances.
DWDM Basics
How does Dense Wavelength-Division Multiplexing (DWDM) work?
DWDM has tighter wavelength spacing that helps fit more channels onto a single fiber. It is best used in systems with more than eight active wavelengths per fiber. Dense wavelength-division multiplexing in optical fiber systems deployed today achieve a throughput of 100 - 400 Gbps. When DWDM is used with network management systems and add-drop multiplexers, carriers are able to adopt optically based transmission networks. This approach helps meet growing bandwidth demand at a significantly lower cost than installing new fiber.
