Tip of the Week – 18 Mar 2014

Tip of the Week: Will your fiber link work at 10G?

There are 3 major parameters one should be aware of when planning a 10G fiber link, Loss, chromatic dispersion and polarization mode dispersion (PMD).

A 10G transceiver’s maximum optical budget is typically less than a 1G transceiver’s maximum budget, and hence maximum reach is less.
Chromatic dispersion limits most 10G transceivers to a maximum fiber span of ~ 80 km over standard fiber (G.652). Any further distance requires proper dispersion compensation or signal regeneration.
Often ignored, PMD can cause significant outages in a fiber span. These outages can be random and difficult to debug. Often equipment is blamed for the outage. Problem PMD values are more common in long older fiber cables installed before year 2000. However, any long fiber cable can experience high PMD. When deploying 10G and faster links, knowing your cable fiber PMD can be very helpful. Best way to measure PMD is with a PMD test set commonly performed during fiber characterization.
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To learn more about this topic and other fiber optic network topics, refer to my following books (publisher McGraw-Hill):

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