IEEE Standard for Ethernet - Amendment 4: Physical Layers and Management Parameters for 50Gb/s, 200Gb/s, and 400Gb/s Operation over Single-Mode Fiber

This amendment to IEEE Std 802.3-2018 adds Physical Layer (PHY) specifications and management parameters for 50 Gb/s, 200 Gb/s, and 400 Gb/s operation over single-mode fiber with reaches of at least 40 km.