GarrettCom P62-Series - Manual (Page 27)

Magnum P62-Series Hardened Switches Installation and User Guide (08/03)
23
www GarrettCom com . .
longer distances, about 20Km with the single-mode SC.
The same procedures as for multi-mode fiber apply to single-mode fiber connectors.
Follow the steps listed in Section 3.2.2 above.
3.2.5 Power Budget Calculations for P62-Series 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
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
µm (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 component manufacturer’s (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
µm
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
P62-
xMSC
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
P62-
xSSC
100Mb
FX
Single-
mode
20
(0.4)
1300 9/125 -15 -31 14 28 17.5 35
“Long
Reach”
100Mb
FX
Single-
mode
40
(0.4)
1300
9/125 -5 -34 27 54 32.5 65
* 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
both applied:
• The 100Mb fiber segment must operate in full-duplex (FDX) mode, 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)