Ethernet standard to cut energy use
By Martin Rowe, Senior Technical Editor- November 1, 2010Reducing energy consumption is on everyone's mind these days, and engineers have developed a standard for Energy Efficient Ethernet, or EEE. The IEEE 802.3az standard, which was approved on September 30, provides a framework for engineers to design EEE-compliant products.
EEE-compliant network devices will add a "sleep" state that lets a transmitter shut down during periods of inactivity. The addition of a sleep state adds complexity to Ethernet devices, test equipment, and test procedures.
A paper by Jeff Lapak and Jon Beckwith, senior engineers at the University of New Hampshire InterOperability Laboratory, explains the testing challenges in detail. (Download "Energy Efficient Ethernet brings on testing challenges").
In some instances of EEE, you will have to remove jitter from parts of your measurements. You will need to either do this in real time or capture the signals and perform post-process analysis. In addition, you will have to verify that an EEE device doesn't enter sleep state incorrectly.
You will also need to measure power consumption using real-world traffic conditions. Simply measuring the energy savings between full traffic and no traffic doesn't represent the energy savings that will occur under real-world traffic conditions.