Not too long ago, local networks replaced 1G with 10G for data delivery, and we are now on the precipice of 100G becoming the new standard for affordable transport beyond 2km. But what about 400G and 800G? As of 2021, 400G and 800G are available, but not affordable for high capacity or long distances using DWDM.

This article focuses on different 100G DWDM systems transporting between 2km and 120km. In telecommunications, you hear these systems sometimes referred to as “last mile” or “Metro.” Within data center circles, they are referred to as “Data Center Interconnects” or “carrier-to-meet-me-room” systems.

100G transport can be accomplished in many ways, not just via coherent optics. PAM4 modulation has opened the door for inexpensive and compact 100G transport solutions. Some of the factors in determining what system to select include: capacity, price, support, ease of use, turn up speed, distance, fiber types, and legacy network integration.

Some questions to ask when determining the best system to choose:

• How many 100G circuits do I currently need to transport?
• What will my capacity look like in 2 to 5 years for 100G circuits?
• What is the fiber distance between location endpoints?
• What does my current capital expenditure budget support?
• Does my current engineering/operations group have the time, the skill, and the capacity to turn up a complex system? If not, is an automated system a better choice?
• What kind of support and warranty are required and at what cost?
• Is this a “Greenfield” application, or do you need to put 100G circuits on your existing passive DWDM deployment?
• What fiber type will your system use? What are the dispersion characteristics? Has the link been “characterized?”

Should your current configurations utilize onboard optics, 100G Media Converters (the “DemarQ”) can be used as a transponder for 100G. With zero-touch Open Line Systems in 40, 16, and 8 channel configurations that go up to 120km, there are plenty of systems that are available to fit your needs for 100G DWDM.