Juniper Networks EX8208 Table51: Estimated Valuesfor Factors Causing Link Loss (continued)

Table51: Estimated Valuesfor Factors Causing Link Loss (continued)
Sample(LL) Calculation ValuesEstimatedLink-Loss ValueLink-LossFactor
Thisexample assumes 5 connectors.
Lossfor 5 connectors:
5(0.5dBm) = 2.5 dBm
0.5dBmConnector
Thisexampleassumes 2 splices. Loss for
twosplices:
2(0.5dBm) = 1dBm
0.5dBmSplice
Thisexample assumes the link is 2 km
long.Fiber attenuation for2 km:
•2km(1.0 dBm/km) = 2 dBm
•2km( 0.5 dBm/km) = 1 dBm
•Multimode—1dBm/km
•Singlemode—0.5 dBm/km
Fiberattenuation
1dBm1dBmClockRecovery Module(CRM)
NOTE: Forinformation about the actual amount of signal loss causedby equipment
andother factors, see your vendor documentation forthat equipment.
2. Calculatethe (P
M
)by subtracting (LL) from (P
B
):
P
B
–LL=P
M
13dBm – 0.5 dBm [HOL] – 5 (0.5 dBm) – 2 (0.5 dBm) – 2 km (1.0 dBm/km) – 1 dB
[CRM]= PM
13dBm – 0.5 dBm – 2.5 dBm – 1 dBm – 2 dBm – 1 dBm = PM
PM=6 dBm
Thecalculatedpower margin is greaterthan zero, indicating thatthe link has sufficient
powerfortransmission. Also, the power margin value does not exceedthe maximum
receiverinput power.Refer to the specificationfor your receiver to find the maximum
receiverinput power.
RelatedTopics •Calculatingthe EX8200 Switch Fiber-Optic CablePower Budget on page 120
•OpticalInterface Support in EX8200 Switches on page60
•UnderstandingEX8200 Switch Fiber-Optic Cable Signal Loss, Attenuation,and
Dispersionon page 106
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