Power Budget Calculations For 4K-Series Fpm's With Fiber Media - GarrettCom 4K-Series Installation And User Manual

Magnum 4K8 Switches
4.8

Power Budget Calculations for 4K-Series FPM'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
T
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
Mode
Std.
Module
FPM10- 10 Mb Multi-
FST mode
FL
FPM10- 10 Mb Single-
FL mode
SST
FPM- 100Mb Multi-
FX mode
MST, MSC
100Mb Single-
FPM-SSC
FX mode
single-
100MB
FPM-SSCL
mode
FX
Long reach
100Mb Multi-
FPM-
FX mode
MTRJ
* 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 .
Installation and User Guide
(min) - P
T
= Transmitter Output Power, and P
Std. Wave Cable
km - Size
µm
fdx length
(hdx) 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)
40 9/125
1300
(0.4)
2 1300 62.5/125
(0.4)
50/125
.
(min)
R
= Receiver Sensitivity
R
µm
(M.m) is 2.8 dB/km,
X'mitr R'cvr Worst
Output Sens. OPB,
P dB P dB dB
T , R ,
-15.0 -31 14
-9.5 -31 19.5
-19.5 -31 9.5
-30 -39 7
-20 -31 9.0
-23.5 -31 5.5
-15 -31 14
-5 -34 27
-20 -31 9.0
-23.5 -31 5.5
27
(10/04)
Worst* typical typical*
distance OPB, distance
Km, fdx dB Km, fdx
5 17 6
5.9 23.5 7
3.4 13.5 4.8
14 13 26
2.5 14 5
2.0 12 4
28 17.5 35
54 32.5 65
3.0 15.8 5.5
2.0 12.2 4.0
only