400GBASE-DR4-2 Application Overview

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400GBASE-DR4
400GBASE-DR4-2: 400 Gb/s PAM4 parallel transmission at 1310 nm over 8 single‑mode optical fibers, with reach up to at least 2 km

400GBASE-DR4-2 supports long wavelength 4‑level pulse amplitude modulated (PAM4) parallel transmission over four lanes (8‑fibers) of single‑mode optical fiber cabling. The application’s equivalent symbol rate is 106.25 GBd per lane (PAM4 maps pairs of bits into a single symbol) and the supported distance varies according to the type of single‑mode cable used. Network equipment interface connections include a multi‑fiber push on (MPO) connector and standard sockets into which physical (PHY) layer transceiver modules may be plugged.

  • Connector type: MPO/MTP
  • Transceiver module: QSFP-DD, OSFP
  • Published as IEEE Std 802.3df™: Media Access Control Parameters for 800 Gb/s and Physical Layers and Management Parameters for 400 Gb/s and 800 Gb/s Operation in 2024
 

Optical Fiber Cabling (Channel) Characteristics:

400GBASE-DR4-2
Parameter OS1a Indoor/Outdoor OS2
Operating 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 four-lane 400 Gb/s PHY 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 support to enable mapping optical transport networks (OTNs)
  • Supports a BER of better than or equal to 10-13 at the MAC/PLS service interface

Related Applications:

The IEEE P802.3df Task Force also specified the following 800 Gb/s Ethernet applications:

Application    Operating    Wavelength(s) Media Operating Range1​
800GBASE-CR8 – Copper Twinax up to 2 m
800GBASE-DR8 1310 nm Single-mode up to 500 m
800GBASE-DR8-2 1310 nm Single-mode up to 2 km
800GBASE-KR8 – Backplane –
800GBASE-SR8 850 nm Multimode up to 100 m
800GBASE-VR8 850 nm Multimode up to 50 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