Cisco 7000 Series Hardware Installation And Maintenance page 75

Site
Requirements
Power
To
design
of
light
the receiver
depends on modulated
Attenuation
common
The
multimode
Chromatic
wavelengths
Modal
the fiber
Attenuation
chromatic
dispersion
dispersion
fiber-optic
Table
Attenuation
Dispersion Limit
The
500 MHzksm
Approximating
LED
The
each
dispersion
and
being
multimode
minimum
of the
all
The
equation
PB
PB
PB
The
follows
PM
the
If
7000 Hardware
2-10 Cisco
Budget
an optical data
efficient
available attenuation
to overcome
to
requires
operate
reaching
light
caused by
the passive
multimode and
both
to
variables reduce
following
transmission
spreading
dispersion
dispersion
spreading
lower
is significantly
and modal
dispersion
decibels
in
penalty
and modal
losses
Table
cable
2-7
Typical Fiber-Optic
Single-Mode
dB
0.5
No
limit
of bandwidth and distance
product
Power
AlP
the
used multimode
for transmission
with
different
path length
smear order
Higher
radiated the
into fiber
assumes
transmissions
PR
receiver
sensitivity
of an actual
system
parts
PB
maximum
power budget the
is
the calculation of the
lists
PR
PT
30
dBm
18.5
dBm
dB
11.5
power margin calculation
is
LL
PB
power margin is
positive
and Maintenance
Installation
link evaluate the
power budget
the optical link
in
within
its
specifications Proper
the receiver with
enough
media components
cables
transmission
single-mode
the
of the signal light
power
of the signal time because
in
of the signal time because
in
than for other
for fiber
optical
reduce the available
power
The
the data
lost over
power
2-7 the factors of attenuation
lists
and
Link Attenuation
Multimode
dB/km
1.0
MHzkm1
500
must be than
less
Margin
source creates multiple propagation
light
cross the optical fiber causing
and time
requirement to
HOL
mode
from
loss results
worst estimate
cladding case
minimum
transmitter
power
The
worst case
analysis provides
the worst
will at
operate
amount of
possible
power budget
from
derived the
power budget
work
the link
will
rule
as
The power
is
budget
minimum
and exceed
the
to
of an
operation
optical
be demodulated
to
power
correctly
and connectors
cable
splices
transmitted the receiver
to
of the
different
speeds
of the
different
propagation
media For multimode
transmission
combined
of the the
system by
sum
link the of the
is
component
and
limit
dispersion
Limits
Dispersion
paths
LED
from
the
entering
light
PM
of
power margin
PT
maximum
link loss
margin of error although
levels
case
The
transmitted
power
following
and
subtracts the
link
loss
amount
the
that
power
data
link
is
in
of
light
modes
in
for typical
of light
signal
the
fiber
for
LL
and
not
as