What Does the Future Hold for PAM-4?

What does the future hold for pulse-amplitude modulation (PAM)? Only five or six years ago PAM-4 was really just a forward-thinking concept to help us reach the realm of 400 gigabit ethernet (400 GbE). Today it's well on its way to becoming a communications standard, with some suggesting it may kill the non-return to zero (NRZ) encoding scheme that previously dominated serial data transmission.

But is PAM-4 the answer to work a world that needs electro-optical signaling beyond 100 GbE? And what are the challenge and opportunities that lay ahead? 

A DesignCon 2018 panel, “The Case of the Closing Eyes: Is PAM the Answer?” gathered a group of experts from companies including Intel, Teledyne-Lecroy, Keysight, Broadcom Limited, and Tektronix, to discuss the feasibility of PAM-4, and the challenges of implementing it. While the trend among engineers looks to be an outright shunning of NRZ, are engineers just trading one set of problems for another?  

The full panel included: Chris Loberg, SeniorTechnical Marketing Manager at Tektronix; signal integrity guru Dr. Ransom Stephens; Martin Miller, a Chief Scientist at Teledyne-LeCroy; Greg LeCheminant, Measurement Applications Specialist, Digital Communications Analysis, Internet Infrastructure Solutions at Keysight Technologies; Pavel Zivny, a Domain Expert at Tektronix; Cathy Liu R&D Director at Broadcom Limited; and Mike Peng Li, a Fellow at Intel.

Watch the full DesignCon 2018 panel below and for more updates be sure to follow Design News on Facebook.  

Chris Wiltz is a Senior Editor at Design News, covering emerging technologies including AI, VR/AR, and robotics.