Serial 100Gbps and PAM4 become the new standard IEEE P802.3bs 400Gbps

IEEEP802.3bs 400Gbs The Working Group agreed to adopt the (physical layer media association) based on a new technology standard single-mode fiber PMD 4 100Gbps wavelength in a recent IEEE 802.1 / IEEE 802.3 joint meeting. This means that the discussion on the serial 100Gbps technology is mature enough to temporarily come to an end several months. Lightwave 1 January article was previously reported that only one third of the members agreed that this standard, another third support 8X50Gbps.

IEEE P802.3bs Working Group members to vote based on PAM-4 modulation techniques 4X100Gbps PMD format, 500 m transmission. The vote also passed 8x50Gbps 10 kilometers of standard, this format also uses a PAM-4 modulation. The modulation format, had previously considered PAM16 and PAM8, but this PAM-4 prevailed.

IEEE P802.3bs Working Group mainly focused on the recent development of 100 meters of multimode fiber, the relevant standard single-mode fiber 500 m, 2 km single-mode fiber and 10 km of single mode fiber. On multimode fiber applications, 16X25Gbps the NRZ format gained rapid adoption. But the single-mode fiber applications, 50Gbps or 100Gbps on a single wavelength, modulation using NRZ or what PAM-4, DMT have been in fierce debate.

Introduced in 400Gbps module 4X100Gbps followed the IEEE 802.3ba of 4X10bps and 4X25Gbps 4-multiplexed tradition, and only use four lasers and detectors to reduce costs. For 4X100Gbps electrical interface, have previously developed PMA (physical layer media connection Attachment) sublayer is not a big problem. But 100Gbps serial technology possible without DSP, DSP prior art power consumption and size is a challenge.