Site Wiring Guidelines
Cisco 12008 Gigabit Switch Router Installation and Configuration Guide
2-24
Subtracting the data link loss from the power budget should produce a result greater than
zero. If a result is less than zero, you may have insufficient power for receiver operation.
For SONET line cards, the signal must meet the signal requirements listed inTable 2-6.
Table2-6 Line Card SONET Signal Requirements

Multimode Power Budget Example (with Sufficient Power for Transmission)

This section contains a sample calculation of a multimode power budget, based on the
following variables:
•Length of multimode link = 3 km
•Four connectors
•Three 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 resulting power budget (PB) value of 5 dB indicates that this link would ha ve suf ficient
power for fiber-optic transmission.
Characteristic Single-Mode Multimode
Minimum transmitter
power (PT) –18.5 –15
Minimum receiver
sensitivity (PR) –30 –28
Power Budget (PB) –11.5 –13