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Magnum Quad-Series Fiber Switches
4.7
Power Budget Calculations for Quad-Series QPM's with Fiber
Media
Receiver Sensitivity and Transmitter Power are the parameters necessary to
compute the power budget. To calculate the power budget of different fiber media
installations using Magnum products, the following equations should be used:
OPB (Optical Power Budget) = P
where P
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
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 component manufacturer's (Agilent's and
Siemens') web sites and catalogs to provide guidance to network designers and installers.
Fiber
Speed,
Port
Std.
Module
QPM10-
10 Mb
FST
FL
QPM-
100Mb
FX
MST, MSC
100Mb
QPM-SSC
FX
100Mb
QPM-
FX
MTRJ
100Mb
QPM-
FX
MV45
* Note: The use of either multi-mode or single-mode fiber to operate at 100Mbps speed
over long distances (i.e., in excess of approx. 400 meters) can be achieved
if the following factors are both applied:
•
The 100Mb fiber segment must operate in full-duplex (FDX) mode, i.e. the
full-duplex (factory default) setting for 100Mbps fiber ports must be used,
and
•
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)
www GarrettCom com
.
(min) - P
T
= Transmitter Output Power, and P
T
Std.
Wave
km
-
Mode
fdx
length
(hdx)
nm
Multi-
2
850
mode
(2)
Multi-
2
1300 62.5/125
mode
(0.4)
Single-
18+
1300
mode
(0.4)
Multi-
2
1300 62.5/125
mode
(0.4)
2
Multi-
1300 62.5/125
(0.4)
mode
.
Installation and User Guide (06/09)
(min)
R
R
Cable
X'mitr
R'cvr
Size
Output
Sens.
μm
P
dB
P
dB
T ,
R ,
62.5/125
-15.0
-31
100/140
-9.5
-31
50/125
-19.5
-31
-20
-31
50/125
-23.5
-31
9/125
-15
-31
-20
-31
50/125
-23.5
-31
-14
-31
34
= Receiver Sensitivity
μ m
(M.m) is 2.8 dB/km,
Worst
Worst*
typical
OPB,
distance
dB
Km, fdx
14
5
19.5
5.9
9.5
3.4
9.0
2.5
5.5
2.0
14
28
9.0
3.0
5.5
2.0
15
5
typical*
OPB,
distance
dB
Km, fdx
17
6
23.5
7
13.5
4.8
14
5
12
4
17.5
35
15.8
5.5
12.2
4.0
16
5.7
only
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