Juniper EX2300 Series Hardware Guide

Calculang the Fiber-Opc Cable Power Budget for EX Series Devices
To ensure that ber-opc connecons have sucient power for correct operaon, calculate the link's
power budget when planning ber-opc cable layout and distances to ensure that ber-opc
connecons have sucient power for correct operaon. The power budget is the maximum amount of
power the link can transmit. When you calculate the power budget, you use a worst-case analysis to
provide a margin of error, even though all the parts of an actual system do not operate at the worst-case
levels.
To calculate the worst-case esmate for ber-opc cable power budget ( P
B
) for the link:
1. Determine values for the link's minimum transmier power ( P
T
) and minimum receiver sensivity
( P
R
). For example, here, ( P
T
) and ( P
R
) are measured in decibels, and decibels are referred to one
milliwa (dBm).
P
T
= – 15 dBm
P
R
= – 28 dBm
NOTE: See the specicaons for your transmier and receiver to nd the minimum
transmier power and minimum receiver sensivity.
2. Calculate the power budget ( P
B
) by subtracng ( P
R
) from ( P
T
):
– 15 dBm – (–28 dBm) = 13 dBm
Calculang the Fiber-Opc Cable Power Margin for EX Series Devices
Before calculang the power margin:
• Calculate the power budget (see "Calculang the Fiber-Opc Cable Power Budget for EX Series
Devices" on page 81).
Calculate the link's power margin when planning ber-opc cable layout and distances to ensure that
ber-opc connecons have sucient signal power to overcome system losses and sll sasfy the
minimum input requirements of the receiver for the required performance level. The power margin ( P
M
)
is the amount of power available aer aenuaon or link loss ( LL ) has been subtracted from the power
budget ( P
B
).
When you calculate the power margin, you use a worst-case analysis to provide a margin of error, even
though all the parts of an actual system do not operate at worst-case levels. A power margin (
P
M
)
greater than zero indicates that the power budget is sucient to operate the receiver and that it does
81

Juniper EX2300 Series Specifications

General

Brand	Juniper
Model	EX2300 Series
Category	Switch
Language	English