What is DWDM (Dense Wavelength Division Multiplexing)?

DWDM allows you to easily add capacity to your network without having to lay down additional fiber. This pay-as-you-grow model is crucial for enterprises dealing with data-intensive applications.

DWDM networks are widely used for transporting high-speed data across medium distances. This can include telecommunications, cable television and enterprise data center interconnects. Typical DWDM systems use optical transponders to translate incoming electrical signals into optical wavelengths. Optical amplifiers boost these wavelengths to overcome spans of attenuation and fiber loss.

What is DWDM?

DWDM (dense wavelength division multiplexing) is a key technology that provides the ultimate scalability, reliability and reach for fibre optic networks. It enables carriers to maximize the use of existing optical fiber cables and to easily provision new services by adding or dropping wavelengths with flexible add/drop modules.

The technology works by finely slicing the ultraviolet light section of the electromagnetic spectrum, and uses precision lasers to separate wavelength channels 0.8 nm apart. This tighter wavelength spacing allows up to 88 high-capacity communication channels to be simultaneously transmitted across a single pair of optical fibres, resulting in a throughput that can exceed 19.2 Tbps.

It’s important to understand the difference between DWDM and Coarse Wavelength Division Multiplexing (CWDM), as this will dwdm-dense-wavelength-division-multiplexing help you decide which technology is the right fit for your requirements. CWDM uses less sophisticated electronics and is capable of supporting up to 18 wavelengths at once, compared with DWDM’s 88.

CWDM is best suited for short distance and middle mile networks, while DWDM is used for access, metro and core/long haul connections. If you require a solution that can handle the higher speeds and higher bandwidth requirements of hyperscale and multi-tenant data centers, DWDM is an excellent choice. Using reconfigurable optical add/drop multiplexers (ROADMs) and network management software, it’s possible to dynamically manage wavelength paths with flexibility to support mesh, ring, linear add/drop and core DWDM topologies without major infrastructure changes.

DWDM Applications

DWDM uses the optical transmission properties of light waves to press together wavelength channels from multiple data streams and combine them into a single optical fiber. This allows for the same amount of traffic to be carried across existing infrastructure, without the expense and disruption of laying more fiber.

Using precision lasers, DWDM creates up to 80 wavelength channels with channel spacing of only 0.8nm or less. This enables far more data to be transmitted over a pair of optical fibres than can be done with Coarse Wavelength Division Multiplexing (CWDM).

A key benefit of DWDM is that it allows for the transport of different protocols and bitrates independently of each other. This means that one network can support all kinds of services from different providers – even those with very different bandwidth requirements.

At the transmitting end, a transponder converts the operating wavelength of an incoming bitstream to the corresponding DWDM channel. Optical add/drop multiplexers remove or add wavelength channels as required along the route. Optical amplifiers can also be used to increase signal strength and lengthen the distance that can be achieved over a link.

DWDM is popular with telecoms providers and cable companies, as it enables them to make the most of their existing fibre optic infrastructure. It’s also a vital component of dense data centers, where the ability to run separate data formats and rates on individual channels helps to streamline operations.

DWDM Costs

DWDM is a complex technology that requires multiple components to function effectively. Its main component is an optical amplifier which can amplify wavelengths and overcome long spans of attenuation or fiber loss. These optical amplifiers can be of several types, including Raman, erbium-doped-fiber amplifiers (EDFA), and booster/inline.

This enables longer distance transmission and overcoming bandwidth bottlenecks within networks. It also helps telecommunications companies scale their backbone networks without the cost and disruption associated with laying new fiber.

The most common application for DWDM is in large data centers. These dense data centers use DWDM to separate different types of traffic rates and protocols from each other and maximize bandwidth. This helps them to meet the demand for high-speed cloud services.

Another important reason for using DWDM is to overcome capacity limits in existing metro networks. Unlike conventional unamplified systems, DWDM connections can be amplified which enables multimode fiber optic cable assemblies supplier them to transport more traffic channels over the same dark fiber link. This saves on equipment and operational costs by eliminating the need for aggregation of traffic signals in SONET/SDH multiplexers or IP routers.

However, the most significant benefit of DWDM is that it eliminates the need to lay new fibre. By enabling different traffic streams to be transmitted simultaneously over an existing dark fibre, it avoids the huge costs and long lead times associated with laying more fibre. This means that investments made in telecommunications infrastructure can be fully realised.

DWDM Benefits

DWDM technology increases bandwidth and optimizes existing fiber networks, making it a crucial component in FTTH solutions. It also provides flexibility by allowing simultaneous transmission of different types of services. This way, service providers can increase revenue and provide reliable Internet connections to customers.

Unlike traditional fixed systems, DWDM uses optical transceivers to multiplex and demultiplex signals on demand. This allows for higher data throughput, better scalability, and lower power consumption. Furthermore, DWDM networks offer superior survivability by using wavelength-based routing, which can avoid problems caused by a transmitter device failure or cable interruption.

DWDM is an essential technology for bringing fast, affordable broadband connectivity to businesses and homes in the modern world. It’s embedded in all aspects of communications at an infrastructural level, and it continues to evolve as fiber optics become more accessible and affordable.