ONS 15454 MSTP Dispersion Compensation Unit


Chromatic dispersion is a fiber nonlinear condition (anomaly) that causes wavelength channels to spread. Because chromatic dispersion varies by wavelength frequency, some optical frequencies spread faster than others, resulting in optical pulses that have spread over several bit periods between transmitter and receiver. The result can be transmission degradation attributed to bit errors, as optical receivers interpret 0 bit pulses and 1s, and vice versa.

To mitigate this effect, DCUs are intermittently placed in the optical fiber path. These DCU modules typically exhibit the exact opposite polarity of the fiber, resulting in a compression effect on the optical pulse as the chromatic dispersion effects become reversed.

The DCU used in the ONS 15454 MSTP system mounts in a separate 1RU chassis, which is typically mounted atop the ONS 15454 MSTP shelf assembly. The DCU chassis contains two slots for DCUs: one for the East path and one for the West path. The DCU consists of a spool of dispersion-compensating fiber, with optical connectors. It is an entirely passive system, requiring no power connections or active management.

Table 9-10 lists the DCU units available for the ONS 15454 MSTP system.

Table 9-10. ONS 15454 MSTP DCU Products

Module Description

Compensation Level

Attenuation

DCU-100

100 ps/nm

2.1 dB

DCU-350

350 ps/nm

3.0 dB

DCU-450

450 ps/nm

3.5 dB

DCU-550

550 ps/nm

3.9 dB

DCU-750

750 ps/nm

5.0 dB

DCU-950

950 ps/nm

5.5 dB

DCU-1150

1150 ps/nm

6.2 dB





Building Multiservice Transport Networks
Building Multiservice Transport Networks
ISBN: 1587052202
EAN: 2147483647
Year: 2004
Pages: 140

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