Green Communications: Principles, Concepts and Practice

Chapter 14Energy Efficiency in Ethernet

Pedro Reviriego¹, Ken Christensen², Michael Bennett³, Bruce Nordman¹ and Juan Antonio Maestro¹

¹Universidad Antonio de Nebrija, Madrid, Spain

²University of South Florida, Florida, USA

³Lawrence Berkeley National Laboratory, Vallejo, USA

14.1 Introduction to Ethernet

Ethernet is the dominant technology for wired local area networks (LANs) used to connect servers and desktop computers. Ethernet has also been adopted for industrial and automotive applications, to connect audio and video equipment and in wireless and wireline access networks. This wide adoption has fostered the continuous development of Ethernet since it was first introduced in the 1970s. In the 1980s, the IEEE 802.3 Ethernet working group was formed to develop Ethernet standards within the IEEE 802 LAN/MAN standards committee. Since then, many Ethernet standards have been produced to cover different transmission media, increased data rates, link aggregation, virtual LANs, Power over Ethernet, congestion management, and other capabilities.

The Ethernet standards support a wide variety of transmission media that include coaxial cables, unshielded twisted pair (UTP), optical fibers, and backplanes [1]. Typically, optical fiber is used for high-speed links between network equipment, whereas UTP is used to provide edge device connectivity. Therefore, the majority of the Ethernet links use UTP as the transmission media. For each medium, different rates are supported, and the ...