Nortel Networks 450 manual Table B-2 1000BASE-SX Transmit Characteristics

Using the BayStack 450 10/100/1000 Series Switch

Transmit Characteristics

Table B-2 lists the transmit characteristics for the 1000BASE-SX models:

Table B-2.	1000BASE-SX Transmit Characteristics
		62.5 Micron	50 Micron
Description		Multimode Fiber	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		See footnote 1	See footnote 1	dBm
Average launch power (minimum)		– 9.5	– 9.5	dBm
Average launch power of OFF transmitter		– 30	– 30	dBm
(maximum)2
Extinction ratio (minimum)		9	9	dB
RIN (maximum)		– 117	– 117	dB/Hz
Coupled Power Ratio (CPR) minimum 3		9 < CPR	9 < CPR	db

1The 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.

2Examples 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.

3Avoid radial overfilled launches even if the launch parameters are within the CPR range.

B-2 302401-D Rev 00