Juniper EX2300 Series - Page 91

not exceed the maximum receiver input power. This means the link will work. A ( P
M
) that is zero or
negave indicates insucient power to operate the receiver. See the specicaon for your receiver to
nd the maximum receiver input power.
To calculate the worst-case esmate for the power margin ( P
M
) for the link:
1. Determine the maximum value for link loss ( LL ) by adding esmated values for applicable link-loss
factors—for example, use the sample values for various factors as provided in Table 23 on page 82
(here, the link is 2 km long and mulmode, and the ( P
B
) is 13 dBm):
Table 23: Esmated Values for Factors Causing Link Loss
Link-Loss Factor Esmated Link-Loss Value Sample (LL) Calculaon Values
Higher-order mode losses
(HOL)
• Mulmode—0.5 dBm
• Single mode—None
• 0.5 dBm
• 0 dBm
Modal and chromac
dispersion
• Mulmode—None, if product of
bandwidth and distance is less
than 500 MHz/km
• Single mode—None
• 0 dBm
• 0 dBm
Connector 0.5 dBm This example assumes 5 connectors.
Loss for 5 connectors:
(5) * (0.5 dBm) = 2.5 dBm
Splice 0.5 dBm This example assumes 2 splices. Loss
for two splices:
(2) * (0.5 dBm) = 1 dBm
Fiber aenuaon
• Mulmode—1 dBm/km
• Single mode—0.5 dBm/km
This example assumes the link is 2
km long. Fiber aenuaon for 2 km:
• (2 km) * (1.0 dBm/km) = 2 dBm
• (2 km) * (0.5 dBm/km) = 1 dBm
Clock Recovery Module (CRM) 1 dBm 1 dBm
82