Black Box LH8050A, Installation And User Manual

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Black Box Mixed-Media Fiber Hubs Installation and User Guide (4/99)
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4.5 Power Budget Calculations for LH8050C and Fiber Media
Receiver sensitivity and Transmitter Power is the only information necessary to
compute the power budget. To calculate the power budget of different fiber media installations
using LH8050A, the following equations should be used:
OPB (Optical Power Budget) = P
T
(min) - P
R
(min)
where P
T
= Transmitter Output Power, and P
R
= Receiver Sensitivity
Worst case OPB = OPB - 1dB(for LED aging) - 1dB(for insertion loss)
Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/Km]
where the “Cable Loss” for 62.5/125 and 50/125
μ
m
(M.m) is 2.8 dB/km,
and the “Cable Loss” for 100/140 (Multi-mode) is 3.3 dB/km,
and the “Cable Loss” for 9/125 (Single-mode) is 0.5 dB/km
The following data has been collected from typical (such as HP’s and Siemens’) web sites and
catalogs to provide guidance to network designers and installers.
Fiber
Port
Module
Speed,
Std.
Mode
Std.km
fdx
(hdx)
Wave
-
length
nm
Cable
Size
μ
m
X’mitr
Output
P
T ,
dB
R’cvr
Sens.
P
R ,
dB
Worst
OPB,
dB
Worst*
Distance
Km, fdx
Typical
OPB,
dB
Typical*
Distance
Km, fdx
LE8055C-
ST,SC
10 Mb
FL
Multi-
mode
2
(2) 850
62.5/125
100/140
50/125
-15.0
-9.5
-19.5
-31
-31
-31 14
19.5
9.5
5
5.9
3.4
17
23.5
13.5
6
7
4.8
LE8055C-
SM(ST,SC)
10 Mb
FL
Single-
mode
10
(5)
1300 9/125 -30 -39 7 14 13 26
LH8051C-
ST,SC
100Mb
FX
Multi-
mode
2
(0.4) 1300
62.5/125
50/125
-20
-23.5
-31
-31
9.0
5.5
2.5
2.0
14
12
5
4
LH8051C-
SMSC
100Mb
FX
Single-
mode
18+
(0.4) 1300
9/125 -15 -31 14 28 17.5 35
LH8053C-
MTRJ
100Mb
FX
Multi-
mode
2
(0.4) 1300
62.5/125
50/125
-20
-23.5
-31
-31
9.0
5.5
3.0
2.0
15.8
12.2
5.5
4.0
LH8053C-
VF45
100Mb
FX
Multi-
mode
2
(0.4) 1300 62.5/125
-14 -31 15 5 16 5.7
LH8050A-
SST, SSC
100Mb
FX
Multi-
mode
2
(n.a)
1300
62.5/125
50/125
-20
-23.5
-31
-31
9.0
5.5
2.5
2.0
14
12
5
4
Note: The use of either multi-mode or single-mode fiber to operate at 100Mbps speed over
long distances (i.e., over approx. 400 meters) can be achieved
only
if the following
factors are applied:
•
The 100Mb fiber segment must operate in full-duplex (Fdx) mode, i.e. an SPM (or
equal external unit such as LB9800A-Fdx) must be used
•
The worst-case OPB of the fiber link must be greater than the fiber cable’s passive
Attenuation.
(Attenuation = Cable loss + LED aging loss + Insertion loss + safety factor)