400GBASE-FR8 Application Overview

by

400GBASE-ER8, 400GBASE-FR4, 400GBASE-FR8, 400GBASE-LR4-6, 400GBASE-LR8
400GBASE-FR8: 400 Gb/s wavelength‑division multiplexed (WDM) PAM4 serial transmission over 2 single‑mode optical fibers, with reach up to at least 2 km

400GBASE-FR8 supports eight long wavelength WDM 4‑level pulse amplitude modulated (PAM4) serial transmission over duplex (2‑fiber) single‑mode optical fiber cabling. The application’s equivalent symbol rate is 425 GBd per lane (PAM4 maps pairs of bits into a single symbol) 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 standard sockets into which physical (PHY) layer transceiver modules may be plugged.

  • Connector type: LC
  • Transceiver module: QSFP-DD, OSFP
  • Defined in clause 122 of the IEEE 802.3 Standard for Ethernet
  • Initially published as IEEE Std 802.3bs™: Media Access Control Parameters, Physical Layers, and Management Parameters for 200 Gb/s and 400 Gb/s Operation in 2017

Optical Fiber Cabling (Channel) Characteristics:

400GBASE-FR8
Parameter OS1a Indoor/Outdoor OS2
Operating wavelengths: 1273.54 nm, 1277.89 nm, 1282.26 nm, 1286.66 nm, 1295.56 nm, 1300.05 nm, 1304.58 nm, and 1309.14 nm
Specification wavelength: 1310 nm
Insertion loss (max): 4.0 dB
Cabled fiber attenuation (max): 1.0 dB/km 0.5 dB/km 0.4 dB/km
Operating range2: 2 m to 1 km1 2 m to 2 km 2 m to 2 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 3.0 dB connection and splice loss allocation.

Key Application Capabilities:

  • Defines a 400 Gb/s PHY using eight WDM lanes for operation over at least 2 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 10-13 at the MAC/PLS service interface
  • Supports optional Energy-Efficient Ethernet operation

Related Applications:

The IEEE P802.3bs Task Force also specified the following 200 Gb/s and 400 Gb/s Ethernet applications:

Application    Operating    Wavelength(s) Media Operating Range1​
200GBASE-DR4 1310 nm Single-mode up to 500 m
200GBASE-FR4 four WDM2 Single-mode up to 2 km
200GBASE-LR4 four WDM3 Single-mode up to 10 km
400GBASE-DR4 1310 nm Single-mode up to 500 m
400GBASE-LR8 eight WDM4 Single-mode up to 10 km
400GBASE-SR16 850 nm Multimode up to 100 m
1 Supported distance varies according to the type of optical fiber cable used.
2 1271 nm, 1291 nm, 1311 nm, and 1331 nm
3 1295.56 nm, 1300.05 nm, 1304.58 nm, and 1309.14 nm
4 1273.54 nm, 1277.89 nm, 1282.26 nm, 1286.66 nm, 1295.56 nm, 1300.05 nm, 1304.58 nm, and 1309.14 nm

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