Transmit characteristics, Table b-2 – Nortel Networks 450 User Manual
Page 242
Using the BayStack 450 10/100/1000 Series Switch
B-2
302401-D Rev 00
Transmit Characteristics
lists the transmit characteristics for the 1000BASE-SX models:
Table B-2.
1000BASE-SX Transmit Characteristics
Description
62.5 Micron
Multimode Fiber
50 Micron
Multimode Fiber
Units
Transmitter type
Shortwave Laser
Shortwave Laser
Signaling speed
1.25 ± 100 ppm
1.25 ± 100 ppm
GBd
Wavelength (l, range)
770 to 860
770 to 860
nm
T rise/T fall (maximum; 20% - 80%; > 830 nm)
0.26
0.26
ns
T rise/T fall (maximum; 20% - 80%; < = 830 nm)
0.21
0.21
ns
RMS spectral width (maximum)
0.85
0.85
nm
Average launch power (maximum)
1
1 The 1000BASE-SX launch power shall be the lesser of the class 1 safety limit, as defined by the IEEE 802.3z standard,
Clause 38.7.2, or the average receive power (maximum), as defined in
See footnote 1
See footnote 1
dBm
Average launch power (minimum)
– 9.5
– 9.5
dBm
Average launch power of OFF transmitter
(maximum)
2
2 Examples of an OFF transmitter are: no power supplied to the PMD, laser shutdown for safety conditions, activation of a
“transmit disable” or other optional laser shutdown conditions. During all conditions when the PMA is powered, the AC
signal (data) into the transmit port will be valid encoded 8B/10B patterns (this is a requirement of the PCS layers),
except for short durations during system power-on-reset or diagnostics when the PMA is placed in a loopback mode.
– 30
– 30
dBm
Extinction ratio (minimum)
9
9
dB
RIN (maximum)
– 117
– 117
dB/Hz
Coupled Power Ratio (CPR) minimum
3
3 Avoid radial overfilled launches even if the launch parameters are within the CPR range.
9 < CPR
9 < CPR
db
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