40GBASE-ER4 Application Overview



40GBASE-ER4: 40 Gb/s wavelength-division multiplexed (WDM) serial transmission over 2 single-mode optical fibers, with reach up to at least 40 km

40GBASE-ER4 supports four long wavelength WDM serial transmission over duplex (2-fiber) single-mode optical fiber cabling. The application’s equivalent symbol rate is 41.25 GBd per lane and the supported distance varies according to the type of single-mode cable used. Network equipment interface connections include a duplex optical fiber connector and a standard socket into which physical (PHY) layer transceiver modules may be plugged.

  • Connector type: LC
  • Transceiver module: QSFP+
  • Defined in clause 87 of the IEEE 802.3 Standard for Ethernet
  • Initially published as IEEE Std 802.3bm™: Physical Layer Specifications and Management Parameters for 40 Gb/s and 100 Gb/s Operation over Fiber Optic Cables in 2015

Optical Fiber Cabling (Channel) Characteristics:

Parameter OS1a Indoor/Outdoor OS2
Operating wavelengths: 1271 nm, 1291 nm, 1311 nm, and 1331 nm
Specification wavelength: 1310 nm
Insertion loss (min)1: 9.0 dB
Insertion loss (max): 18.5 dB
Cabled fiber attenuation (max): 1.0 dB/km 0.5 dB/km 0.4 dB/km
Operating range2: 2 m to 15 km3 2 m to 30 km3 2 m to 40 km4
1 Minimum channel insertion loss may be achieved by use of an optical attenuator.
2 Maximum operating ranges are calculated using a 2.0 dB connection and splice loss allocation.
3 Operating range for cabled fibers having other than 0.4 dB/km attenuation is not specified by IEEE 802.3. These calculations are provided for information only.
4 Links longer than 30 km for the same link power budget are considered engineered links and must not exceed specified insertion loss.

Key Application Capabilities:

  • Defines a 40 Gb/s PHY using four WDM lanes for operation over at least 40 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
  • Provides appropriate support for optical transport networks (OTNs)
  • Supports a BER of better than or equal to 10-12 at the MAC/PLS service interface
  • Supports optional Energy-Efficient Ethernet operation

Related Applications:

The IEEE P802.3bm Task Force also specified the following Ethernet application:

Application    Operating    Wavelength(s) Media Operating Range1
100GBASE-SR4 850 nm Multimode up to 150 m
1 Supported distance varies according to the type of optical fiber cable used.

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