Worst-case power budget and penalties, Table b-8 – Nortel Networks 450 User Manual
Page 246
Using the BayStack 450 10/100/1000 Series Switch
B-6
302401-D Rev 00
Worst-Case Power Budget and Penalties
lists the worst-case power budget and penalties for the 1000BASE-LX
models:
Receive sensitivity
– 19
dBm
Return loss (minimum)
12
dB
Stressed receive sensitivity
1
,
2
– 14.4
dBm
Receive electrical 3 dB upper cutoff frequency (maximum)
1500
MHz
Vertical eye-closure penalty
3
2.60
dB
1
Measured with conformance test signal at TP3 (see IEEE 802.3, Clause 38.6.11) for BER = 10
–12
at the eye center.
2
Measured with a transmit signal having a 9 dB extinction ratio. If another extinction ratio is used, the stressed receive
sensitivity should be corrected for the extinction ratio penalty.
3
Vertical eye-closure penalty is a test condition for measuring stressed receive sensitivity. It is not a required
characteristic of the receiver.
Note:
The link power penalties (
) are used for link power budget
calculations only. They are not requirements and are not meant to be tested.
Table B-8.
Worst-Case 1000BASE-LX Power Budget and Penalties
Parameter
62.5 um MMF
50 um MMF
10 um SMF
Unit
Modal bandwidth as measured at
1300 nm (minimum, overfilled launch)
500
400
500
N/A
MHz · km
Link power budget
7.5
7.5
7.5
8.0
dB
Operating
distance 550
550
550
5000
m
Channel insertion loss
2.35
2.35
2.35
4.57
dB
Link power penalties
3.48
5.08
3.96
3.27
dB
Unallocated margin in link power budget
1.67
0.07
1.19
0.16
dB
Table B-7.
1000BASE-LX Receive Characteristics
(continued)
Description Value
Units
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