Nortel Networks 450 - Manual (Page 242)

Using the BayStack 450 10/100/1000 Series Switch
B-2 302401-D Rev 00
Transmit Characteristics
Table B-2 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 Table B-3 .
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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