GE Multilink ML3000, Инструкция по эксплуатации

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4–4 MULTILINK ML3000 ETHERNET COMMUNICATIONS SWITCH – INSTRUCTION MANUAL
OPERATION CHAPTER 4: OPERATION
4.1.8 Power Budget Calculations 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
MultiLink products, the following equations should be used:
(EQ 4.1)
where: OPB = optical power budget
P
T
= transmitter output power
P
R
= Receiver Sensitivity
The worst case OPB is as follows:
(EQ 4.2)
The worst-case distance is calculated as follows:
(EQ 4.3)
The cable loss in dB/km is defined in the following table:
The following data has been collected to provide guidance to network designers and
installers.
Table 4–1: Cable losses
Cable size Mode Cable loss
62.5 / 125 μ m multi-mode 2.8 dB/km
50 / 125 μ m multi-mode 2.8 dB/km
100 / 140 μ m multi-mode 3.3 dB/km
9 / 125
μ
m single-mode 0.5 dB/km
0.4 dB/km (LXSC25)
0.25 dB/km (LXSC40)
0.2 dB/km (LXSC70)
OPB P
t min
( )
P
R min
( )
– =
OPB
worst
OPB 1dB (LED aging)
–
1dB (insertion loss)
– =
distance
worst
worst-case OPB (in dB)
cable loss (in dB/km)
-------------------------------------------------------- =
Table 4–1: Power budget values for various modules
Fiber
Module
Speed, Std. Mode Std.
km fdx
(hdx)
Wave-
length
nm
Cable
Size ìm
X’mitr
Output PT
, dBm
R’cvr
Sens. PR
,dBm
Worst
OPB,
dBm
Worst*
distance
Km, fdx
typical
OPB,
dBm
typical*
distance
Km, fdx
D 10 Mb FL Multi- 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
E, F 100 Mb FX Multi- 2+ (0.4) 1310 62.5/125
50/125
-20
-23.5
-31
-31
9.0
5.5
3.0
2.0
14
12
5
4
W 100 Mb FX Single- 18+
(0.4)
1310 9/125 -20 -31 9 18 12.5 25
J 100 Mb FX Single- 18+
(0.4)
1310 9/125 -20 -31 9 18 12.5 25
L 100 Mb FX Single- 40+ 1310 9/125 -5 -34 27 54 32.5 65
H, T 100 Mb FX Multi- 2+ (0.4) 1310 62.5/125
50/125
-19
-23.5
-31
-31
10
5.5
3.5
2.0
15.8
12.2
5.5
4.0
G, S 100 Mb FX Multi- 2+ (0.4) 1310 62.5/125 -19 -31 10 3.5 18 6.5
K, U 100 Mb FX Single- 18+ 1310 9/125 -15 -31 14 28 23 46
M, Z 100 Mb FX Single- 40+ 1310 9/125 -5 -34 27 54 32.5 65
B 1000 Mb SX
(Gigabit)
Multi- 0.55+
(0.22)
850 62.5/125
50/125
-9.5 -17 5.5 2 10.5 4
C 1000 Mb SX +
Extn. Dist.
Multi- 2+ 1310 62.5/125
50/125
-9.0 -19 8 2.8 12 4