Multimode Power Budget Example With Sufficient Power For Transmission; Multimode Power Budget Example Of Dispersion Limit - Cisco GSR12/60 - 12012 Router -AnyLAN, SONET/SDH Installation And Configuration Manual

Site Requirement Guidelines

Multimode Power Budget Example with Sufficient Power for Transmission

The following is an example calculation for a multimode power budget based on the
following variables:
Length of multimode link = 3 kilometers (km)
4 connectors
3 splices
Higher order loss (HOL)
Clock recovery module (CRM)
Estimate the power budget as follows:
PB = 13 dB – 3 km (1.0 dB/km) – 4 (0.5 dB) – 3 (0.5 dB) – 0.5 dB (HOL) – 1 dB (CRM)
PB = 13 dB – 3 dB – 2 dB – 1.5 dB – 0.5 dB – 1 dB
PB = 5 dB
The value of 5 dB indicates that this link would have sufficient power for transmission.

Multimode Power Budget Example of Dispersion Limit

Following is an example with the same parameters as the previous example, but with a
multimode link distance of 4 km:
PB = 13 dB – 4 km (1.0 dB/km) – 4 (0.5 dB) – 3 (0.5 dB) – 0.5 dB (HOL) – 1 dB (CRM)
PB = 13 dB – 4 dB – 2 dB – 1.5 dB – 0.5 dB – 1 dB
PB = 4 dB
The value of 4 dB indicates that this link would have sufficient power for transmission;
however, due to the dispersion limit on the link (4 km x 155.52 MHz > 500 MHzkm), this
link would not work with multimode fiber. In this case, single-mode fiber would be the
better choice.
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