The next generation Ethernet step forward to 400 Gb/s. In March 2013 a IEEE study group (802.3) has been established looking for the technology path to cost-effective 400 Gb/s Ethernet. One method to increase the number of Bits per symbol is to use PAM instead of NRZ. An other attractive method is use multiple electrical channels (multi tone) technology. More on: 400 Gb/s Ethernet Public Area.
Huawei Technologies Co., LTD, May 2013