IEEE 802.3bj

The IEEE 802.3bj working group is concerned with 100 Gigabit Ethernet as backplane Ethernet. In this technology, four differential signals with a data rate of 25 Gbit/s are transmitted via four copper wire pairs.

According to the specifications of the 802.3bj working group, the bridgeable distance in the backplane is one meter and requires that the four lanes meet certain channel performance requirements. For this performance evaluation, the channel operation margin( COM) was developed, which includes the entire channel, including the cable and connectors.

In 802.3bj, forward error correction( FEC) is specified, which allows higher insertion loss. In addition, multi- level coding( MLC) is supported in the form of PAM4 and PAM2.