Energy Efficiency in Ethernet

For many years, energy efficiency has only been a priority in communication systems when it directly affected system cost or performance. For example in mobile communications, energy consumption directly impacts battery life and therefore systems are designed to minimize it. In wireline systems, power normally comes from the mains and the focus has been on reducing the peak power consumption of the systems. The peak consumption limits the integration of components on the same integrated circuit or equipment thus impacting the system cost. In addition, many individual system elements such as packaging, ventilation, power supplies, and other components have to be dimensioned for the peak power consumption. This was the case in Ethernet for many years. In the last decade, this situation has changed and energy efficiency has been incorporated as an objective when designing wireline communication systems. Ethernet has been one of the technologies that drove this change for greater energy efficiency with the Energy‐Efficient Ethernet standard “IEEE Std 802.3az: Energy‐Efficient Ethernet‐2010” for which savings are likely to exceed $250 million/year in the United States alone. In this chapter, an overview of energy efficiency in Ethernet is presented covering the existing Energy‐Efficient Ethernet standard as well as ongoing standardization efforts and future directions.