Power Budget Calculations For Fiber Media - GarrettCom Magnum 8000X Installation And User Manual

Magnum 8000X Mixed-Media Fiber Hubs
4.5 Power Budget Calculations for 8000X FPM's and 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 (HP's and
Siemens') web sites and catalogs to provide guidance to network designers and
installers.
Fiber Speed,
Port
Mode
Std.
Module
FPM10- Multi-
10 Mb
MST, MSC mode
FL
FPM10- 10 Mb Single-
SST, SSC FL mode
FPM- Multi-
100Mb
mode
FX
MST, MSC
Single-
100Mb
FPM-SSC
mode
FX
FPM-MTRJ 100Mb Multi-
FX mode
FPM-MV45 100Mb Multi-
FX mode
FPM-SX Multi-
10/100
MST, MSC mode
Mb SX
SPM-FDST 100Mb Multi-
FX mode
SPM-FDSC
* 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
following factors are both applied:
•
The 100Mb fiber segment must operate in full-duplex (FDX) mode, i.e. an
SPM (or equal external unit such as 300ES-FDX) 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)
.
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(min) - P
T
= Transmitter Output Power, and P
T
Std. Cable
km Wave
fdx -
(hdx) length
nm
62.5/125
2
850 100/140
(2)
50/125
10
1300 9/125
(5)
2 1300 62.5/125
(0.4)
50/125
18+
1300 9/125
(0.4)
2 1300 62.5/125
(0.4)
50/125
2
1300 62.5/125
(0.4)
0.3
850 62.5/125
(0.3)
2 1300 62.5/125
(n.a.) 50/125
.
Installation and User Guide (05/ 02)
(min)
R
= Receiver Sensitivity
R
µm
X'mitr R'cvr Worst
Size Output Sens.
µm
P dB OPB,
R ,
P dB
T ,
-15.0 -31
-9.5 -31
-19.5 -31 9.5
-30 -39
-20 -31
-23.5 -31
-15 -31
-20 -31
-23.5 -31
-14 -31
-12 -15
-20 -31
-23.5 -31
40
(M.m) is 2.8 dB/km,
Worst* typical
distance OPB,
Km, fdx dB
dB
14 5 17
19.5 5.9 23.5
3.4 13.5
7 14 13
9.0 2.5 14
5.5 2.0 12
14 28 17.5
9.0 3.0 15.8
5.5 2.0 12.2
15 5 16
1 0.3 1.5
9.0 2.5 14
5.5 2.0 12
only
typical*
distance
Km, fdx
6
7
4.8
26
5
4
35
5.5
4.0
5.7
0.5
5
4
if the