Cisco 7000 Hardware Installation And Maintenance page 82

Site Requirements
Table 2-10 lists the factors that contribute to link loss and the estimate of the link loss value
attributable to those factors.
Table 2-10
Link Loss Factor
Higher order mode losses
Clock recovery module
Modal and chromatic dispersion Dependent on fiber and wavelength used
Connector
Splice
Fiber attenuation
After calculating the power budget minus the data link loss, the result should be greater than zero.
Results less than zero may have insufficient power to operate the receiver.
For SONET versions of the AIP module, the signal must meet the minimum parameters listed
in Table 2-11.
Table 2-11
PT
PR
PB
Multimode Power Budget Example with Sufficient Power for Transmission
The following is an example multimode power budget calculation based on the following variables:
Estimate the power budget as follows:
The value of 2.5 dB indicates that this link would have sufficient power for transmission.
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Estimating Link Loss
AIP SONET Minimum Signal Requirements
Single-Mode Multimode
–18.5 –15
–30 –28
–11.5 –13
Length of multimode link = 3 kilometers (km)
4 connectors
3 splices
Higher order loss (HOL)
Clock recovery module (CRM)
PB = 11.5 dB – 3 km (1.0 dB/km) – 4 (0.5 dB) – 3 (0.5 dB) – 0.5 dB (HOL) – 1 dB (CRM)
PB = 11.5 dB – 3 dB – 2 dB – 1.5 dB – 0.5 dB – 1 dB
PB = 2.5 dB
Estimate of Link Loss Value
0.5 dB
1 dB
0.5 dB
0.5 dB
1 dB/km