Fiber-Optic And Network Cable Specifications For The M7I Router; Related Documentation; Signal Loss In Multimode And Single-Mode Fiber-Optic Cable For The M7I Router; Calculating Power Budget For Fiber-Optic Cable For M Series, Mx Series, And T Series Routers - Juniper M7i Hardware Manual

Related
Documentation
Copyright © 2019, Juniper Networks, Inc.
The power margin ( ) is calculated as follows:
P
M
P = P – LL
M B
P = 13 dB – 2 km (1.0 dB/km) – 5 (0.5 dB) – 2 (0.5 dB) – 0.5 dB [HOL] – 1 dB [CRM]
M
P = 13 dB – 2 dB – 2.5 dB – 1 dB – 0.5 dB – 1 dB
M
P = 6 dB
M
The following sample calculation for an 8-km-long single-mode link with a power budget
( ) of 13 dB uses the estimated values from
P
B
( ) as the sum of fiber attenuation (8 km @ 0.5 dB/km, or 4 dB) and loss for seven
LL
connectors (0.5 dB per connector, or 3.5 dB). The power margin (
follows:
P = P – LL
M B
P = 13 dB – 8 km (0.5 dB/km) – 7(0.5 dB)
M
P = 13 dB – 4 dB – 3.5 dB
M
P = 5.5 dB
M
In both examples, the calculated power margin is greater than zero, indicating that the
link has sufficient power for transmission and does not exceed the maximum receiver
input power.
Fiber-Optic and Network Cable Specifications for the M7i Router on page 91
Signal Loss in Multimode and Single-Mode Fiber-Optic Cable for the M7i Router on
page 92
Attenuation and Dispersion in Fiber-Optic Cable on M Series, MX Series, and T Series
Routers on page 91
Calculating Power Budget for Fiber-Optic Cable for M Series, MX Series, and T Series
Routers on page 93
Chapter 12: Network Cable and Transceiver Planning
Table 51 on page 94 to calculate link loss
) is calculated as
P
M
95