Juniper EX4400 - Page 144

Table 75: Esmated Values for Factors Causing Link Loss (Connued)
Link-Loss Factor Esmated Link-Loss Value Sample (LL) Calculaon Values
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
NOTE: For informaon about the actual amount of signal loss caused by equipment and other
factors, see your vendor documentaon for that equipment.
2. Calculate the ( P
M
) by subtracng ( LL ) from ( P
B
):
P
B
– LL = P
M
(13 dBm) – (0.5 dBm [HOL]) – ((5) * (0.5 dBm)) – ((2) * (0.5 dBm)) – ((2 km) * (1.0 dBm/km)) – (1 dB
[CRM]) = P
M
13 dBm – 0.5 dBm – 2.5 dBm – 1 dBm – 2 dBm – 1 dBm = P
M
P
M
= 6 dBm
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