1000BASE-LX Application Overview


1000BASE-LX: 1,000 Mb/s serial transmission at a 1270 nm to 1355 nm long light wavelength over 2 single‑mode optical fibers, with reach up to at least 5 km

1000BASE-LX supports long wavelength serial transmission over duplex (2‑fiber) single‑mode optical fiber cabling. The application’s nominal symbol rate is 1.25 GBd per lane and the supported distance varies according to the type of single‑mode cable used. Network equipment interface connections include duplex optical fiber connectors and a standard socket into which physical (PHY) layer transceiver modules may be plugged.

  • Connector type: SC, LC
  • Transceiver module: SFP
  • Defined in clause 38 of the IEEE 802.3 Standard for Ethernet
  • Initially published as IEEE Std 802.3z™: Media Access Control Parameters, Physical Layers, Repeater and Management Parameters for 1,000 Mb/s Operation in 1998

Optical Fiber Cabling (Channel) Characteristics:

Parameter OS1a Indoor/Outdoor OS2
Operating wavelengths: 1270 nm to 1355 nm
Specification wavelength: 1310 nm
Insertion loss (max): 4.5 dB
Cabled fiber attenuation (max): 1.0 dB/km 0.5 dB/km 0.4 dB/km
Operating range2: 2 m to 2.5 km1 2 m to 5 km 2 m to 5 km
1 Operating range for cabled fibers having more than 0.5 dB/km attenuation is not specified by IEEE 802.3. This calculation is provided for information only.
2 Maximum operating ranges are calculated using a 2.0 dB connection and splice loss allocation.

Key Application Capabilities:

  • Defines a 1,000 Mb/s PHY for operation over at least 5 km of SMF
  • Supports full-duplex operation only
  • Preserves the Ethernet frame format utilizing the Ethernet MAC
  • Preserves minimum and maximum FrameSize of current 802.3 Standard for Ethernet

Related Applications:

The IEEE P802.3z Task Force also specified the following 1000 Mb/s Ethernet applications:

Application    Operating    Wavelength Media Operating Range1
1000BASE-LX 1270 to 1355 nm Multimode up to 600 m3
1000BASE-SX 770 to 860 nm Multimode2 up to 1.1 km3
1 Supported distance varies according to the type of optical fiber cable used.
2 Use of mode conditioning launch cords is not required for OM3, OM4, or OM5.
3 OM3, OM4, and OM5 had not been standardized when 1000BASE-LX was developed. Calculated operating range assumes two standards compliant connector pairs in a channel and is provided for system planning purposes only.

Back to TIA FOTC IEEE 802.3 Single-mode Optical Fiber Ethernet Standards Explorer