Juniper EX4300 Series

Table 58: Esmated Values for Factors Causing Link Loss (Connued)
Link-Loss Factor Esmated Link-Loss Value Sample (LL) Calculaon Values
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
The calculated power margin is greater than zero, indicang that the link has sucient power for
transmission. Also, the power margin value does not exceed the maximum receiver input power.
Refer to the specicaon for your receiver to nd the maximum receiver input power.
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