Juniper EX2300 Series Hardware Manual page 91

not exceed the maximum receiver input power. This means the link will work. A (
negative indicates insufficient power to operate the receiver. See the specification for your receiver to
find the maximum receiver input power.
To calculate the worst-case estimate for the power margin (
1. Determine the maximum value for link loss (
factors—for example, use the sample values for various factors as provided in
(here, the link is 2 km long and multimode, and the (
Table 23: Estimated Values for Factors Causing Link Loss
Link-Loss Factor
Higher-order mode losses
(HOL)
Modal and chromatic
dispersion
Connector
Splice
Fiber attenuation
Clock Recovery Module (CRM)
LL ) by adding estimated values for applicable link-loss
P
) is 13 dBm):
B
Estimated Link-Loss Value
•
Multimode—0.5 dBm
•
Single mode—None
•
Multimode—None, if product of
bandwidth and distance is less
than 500 MHz/km
•
Single mode—None
0.5 dBm
0.5 dBm
•
Multimode—1 dBm/km
•
Single mode—0.5 dBm/km
1 dBm
P
M
P
) for the link:
M
Table 23 on page 82
Sample (LL) Calculation Values
•
0.5 dBm
•
0 dBm
•
0 dBm
•
0 dBm
This example assumes 5 connectors.
Loss for 5 connectors:
(5) * (0.5 dBm) = 2.5 dBm
This example assumes 2 splices. Loss
for two splices:
(2) * (0.5 dBm) = 1 dBm
This example assumes the link is 2
km long. Fiber attenuation for 2 km:
•
(2 km) * (1.0 dBm/km) = 2 dBm
•
(2 km) * (0.5 dBm/km) = 1 dBm
1 dBm
) that is zero or
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