Nortel Networks 450 - Manual (Page 245)

Gigabit Fiber Optical Characteristics
302401-D Rev 00 B-5
Transmit Characteristics
Table B-6 lists the transmit characteristics for the 1000BASE-LX models:
Receive Characteristics
Table B-7 lists the receive characteristics for the 1000BASE-LX models:
Table B-6. 1000BASE-LX Transmit Characteristics
Description
62.5 Micron
Multimode Fiber 50 Micron
Multimode Fiber
10 Micron
Single-Mode
Fiber
Unit
Transmitter type Longwave Laser Longwave Laser Longwave Laser
Signaling speed (range) 1.25 ± 100 ppm 1.25 ± 100 ppm 1.25 ± 100 ppm GBd
Wavelength (range) 1270 to 1355 1270 to 1355 1270 to 1355 nm
T rise /T fall
(maximum 20-80% response time) 0.26 0.26 0.26 ns
RMS spectral width (maximum) 4 4 4 nm
Average launch power (maximum) – 3 – 3 – 3 dBm
Average launch power (minimum) – 11.5 – 11.5 – 11.0 dBm
Average launch power of OFF
transmitter (maximum) – 30 – 30 – 30 dBm
Extinction ratio (minimum) 9 9 9 dB
RIN (maximum) – 120 – 120 – 120 dB/Hz
Coupled Power Ratio (CPR) 1
1 Due to the dual media (single-mode and multimode) support of the LX transmitter, fulfillment of this specification requires
a single-mode fiber offset-launch mode-conditioning patch cord described in IEEE 802.3, Clause 38.11.4 for MMF
operation. This patch cord is not used for single-mode operation.
28 < CPR < 40 12 < CPR < 20 N/A dB
Table B-7. 1000BASE-LX Receive Characteristics
Description Value Units
Signaling speed (range) 1.25 ± 100 ppm GBd
Wavelength (range) 1270 to 1355 nm
Average receive power (maximum) – 3 dBm
(continued)
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