The Dense Wave Multiplexing DWDM channel or light wavelength matrix (please see chart below) has brought tremendous benefit to the metropolitan and long haul data transmission world.
Bandwidth hungry applications are requiring more information over the same transport infrastructure with the explosive growth of the internet. With CWDM and DWDM Optics, the carrying capacity of the physical medium (fiber) is increased because each DWDM/CWDM channel is transmitted at a different frequency. Many engineers refer to this as the ‘rainbow’ of light, where each channels represents a color of light available within or over the medium (fiber).
DWDM also has the ability to amplify all the wavelengths at the same moment, without first having to convert them to electrical signals, as well as the ability to carry signals of different speeds and types simultaneously over the medium (fiber). This is called protocol and bit rate independence.
DWDM is a big winner in the Metropolitan backbone. It is fast and flexible in the provisioning of protocol- and bit rate-transparent, data centric, protected services, and has the ability to offer new and higher speed services at less cost.
The key requirements for DWDM systems in the Metropolitan area include: Multi-protocol support, cost effectiveness, reliability and availability, openness (interfaces, network management, standard fiber types, electromagnetic compatibility, ease of installation and management, size and power consumption, and scalability.
Overall, the technical advantages to DWDM (Bandwidth Aside) are: DYNAMIC PROVISIONING (Provides engineers the ability to provision in days, not months, because of its fast and simple connections), SCALABILITY (DWDM leverages the available dark fiber to meet the demand for capacity on point to point links and existing SONET/SDH rings), and TRANSPARANCY (It can transparently support TDM and data formats such as Gigabit Ethernet, ATM, ESCON, and fiber channel wit open interfaces over a common physical layer.
DWDM enables a large savings on regenerators (RPTR) and amplifier infrastructure compared to the typical SONET/SDH optical networks, greatly reducing up front infrastructure cost barriers. Besides the lowered infrastructure cost benefit, the DWDM systems have simplified the of network capacity by problem in many ways.