What is DWDM and why do you need it?
As your customer base grows, your data transfer needs also grow. You may encounter bandwidth, performance, and security issues. You may also have limited resources and a limited budget.
That's when the Wave Multiplication System (WDM) comes in, which can solve these problems by enabling a scalable, efficient and secure network infrastructure. With it, you can transfer large amounts of data with greater speed and accuracy, saving you time and money.
How does DWDM work?
Transmitter-side wave multiplication systems use appropriate multiplexers to combine several optical signals, while on the receiver side demultiplexers to separate them again. Since there are 3 different types of WDM systems, this technology is often referred to as xWDM.
Types of WDM systems
- WDM — is a system that uses 2 “standard” wavelengths, the most common: 1310 nm and 1550 nm
- CWDM — (coarse WDM) is a system that uses 18 wavelengths from 1270 nm to 1610 nm with a step every 20 nm, described in the 2002 ITU-T G.694.2 standard
- DWDM — (dense WDM) is a system that uses 48 wavelengths in the C band on a 100 GHz network, described in the 2002 ITU-T G.694.1 standard. In subsequent extensions of this standard, a 50 GHz network (96 channels) and subsequent ones were added. At the time of the creation of this article, systems based on these two grids are the most popular.
How did DWDM systems come about?
DWDM systems are such a fundamental element of today's global networks that it is difficult to imagine the world before their introduction, and yet their history is... less than 20 years.
Dreams of wavelength multiplexing have accompanied the telecommunications world for a long time, and the invention of the optical amplifier in the late 1980s theoretically made it possible to amplify multiple optical channels in a single device without having to demultiplexing them. During this period, optical transmission systems required regeneration of each stream independently every few tens of kilometers, so a DWDM system with an optical amplifier offered tremendous potential for cost reduction.
The first attempts to realize the dreams of a WDM system and optical amplification were not sophisticated systems, but rather primitive sets of devices combining 2 or 4 wavelengths, requiring manual adjustment and tuning. Only 1996 brought a change and the first DWDM system appeared on the market with 16 channels with a bitrate of 2.5 Gbps each. Current systems usually have 96 channels, each of which can operate at speeds of up to 100 Gbps and higher.
The story above shows how often it takes two innovations combined into one to make a revolution. Personal computers did not revolutionize office life until they were combined with printers. Similarly with DWDM networks, huge benefits have emerged with the use of EDFA amplifiers. Full recovery was very expensive, and EDFA amplifiers simply replicated incoming photons and sent out more photons of the same wavelength.
Before that, each of the optical channels had to be regenerated independently. With DWDM, instead of dozens of regenerators, one EDFA amplifier for the entire fiber is now sufficient.
This revolution, which we use to this day, has not completely eliminated the need to fully regenerate data streams, but made it possible to build regeneration nodes not every 50-80 km, but every 1000-1500 km.
Advantages of using DWDM
If you want Increase the bandwidth of your network without the need to invest in additional optical fibers, the use of DWDM technology is the ideal solution. With it, you can Reduce costs and reduce the number of devices needed to support the network.
Moreover, the DWDM system provides greater reliability and resistance to interference, through the use of redundancy. By choosing DWDM technology, you get an efficient and reliable network to meet your needs.
As we already wrote in the article Understand coherent transmission, new technologies have also made it possible to significantly increase the bandwidth of DWDM system channels. This is crucial due to the fact that the gain area of EDFA is limited to about 40 nm. So the same fiber that in 1996 could carry 16 channels with a bandwidth of 2.5 Gbps, today can transfer almost 20 Tbps. Do you want to make better use of your fiber infrastructure?
Do you want to make better use of your fiber optic infrastructure? Take advantage of DWDM!
Whether you own dark fibers or have a single channel at your disposal in your existing DWDM system, we will be happy to help you make the most of them.
Ask about the possibilities of optimizing your network: sales@salumanus.com
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