1000BASE-LX optical Ethernet specification

Overview

The 1000BASE-LX PTMs can be used for GbE, 1Gbps and 2 Gbps service over Single-Mode Fiber (SMF).

System specifications

The following are the 1000BASE-LX system specifications:

• Optical Line Rate: 1.25 Gb/s (±100 ppm)

• Optical Line Coding: 8B/10B

• Fiber Type: 10 μm SMF

• Minimum Range: 2 to 10,000 meters

• Performance: Long-reach

GbE compliance

The PTM optics are compliant with GbE specifications.

Transmitter specifications

The optical 1000BASE-LX optical transmitter meets the specifications defined in IEEE802.3. The table below shows some of the 1000BASE-LX optical transmitter specifications.

Table 10-40: 1000BASE-LX transmit specifications

Description	1000BASE-LX
Transmitter type	Longwave Laser
Signaling speed (range)	1.25 GBd (±100 ppm)
Wavelength (λ, range)	1270 to 1355 nm
Trise/Tfall (max; 20%−80% response time)	0.26 ns
Maximum RMS Spectral Width (σ)	4 nm
Average launch power (max)	−3.0 dBm
Average launch power (min)	−11.0 dBm
Average launch power of OFF transmitter (max)	−30.0 dBm
RIN (max)	−120 dB/Hz

Receiver specifications

The 1000BASE-LX receiver meets the specifications defined in IEEE 802.3. The table below shows some of the 1000BASE-LX optical receiver specifications.

Table 10-41: 1000BASE-LX receive specifications

Description	1000BASE-LX
Signaling speed (range)	1.25 GBd (±100 ppm)
Wavelength (range)	1270 to 1355 nm
Average receive power (max)	−3.0 dBm
Receive sensitivity	−19.0 dBm
Return loss (min) 1	12.0 dB
Receive electrical 3 dB upper cutoff frequency (max)	1500 MHz

Notes:

1. Refer to the IEEE802.3 standards for more information about return loss (min).

Link budgets

The worst-case power budget and link penalties for a 1000BASE-LX channel are shown in the table below.

Table 10-42: 1000BASE-LX link budgets and penalties

Parameter	1000BASE-LX
Link power budget	+8.0 dB
Operating distance	10,000 m
Allocation for link penalties 1	+2.0 dB

Notes:

1. A wavelength of 1270 nm is used to calculate the link penalty.