50-400G Ethernet (PAM4)

PAM4 Serdes 56Gbps

PAM4 is the new essential technique for high-speed networking equipment and was developed to support the Internet of Things (IoT), 5G, and similar next-generation technologies.

Pulse Amplitude Modulation (PAM) increases the number of bits in serial data transmissions by using several pulse amplitude levels. Unlike the NRZ modulation technique, which uses two voltage levels to represent logic 0 and logic 1, PAM4 uses four voltage levels to represent four combinations of two bits logic – 11, 10, 01, and 00. With this a SerDes speed of 56Gbps can be achieved, keeping the Baud rate (symbol rate) at 28GBaud.

Because PAM4 allows more data to be transmitted faster, it was chosen as the underlying technology for enabling 400 Gigabit Ethernet traffic.

Xena uses PAM4 in its Valkyrie traffic generation and analysis solutions with the Thor test modules.

The Thor test modules have the unique advantage of supporting both NRZ speeds (10/25/40/50/100GE) and PAM4 (50/100/200/400GE) speeds. This makes Thor a convenient & cost-effective alternative to the big-brand vendors.

This video shows how quick and easy it is to view PAM4 400GE FEC errors using ValkyrieManager and Xena’s “live demo” system.