Performance Evaluation of Energy Efficient Ethernet

Until very recently, energy efficiency has received little attention in many wired communications environments. For example, in most current Ethernet standards the transmitter and receiver operate at full power even when no data is being sent. However, new upcoming energy-aware standards, such as Energy Efficient Ethernet (EEE), are addressing this issue by introducing a low power mode for idle link intervals. The future EEE standard defines the procedure to enter and exit the low power mode. With EEE the actual energy savings will depend on the amount of traffic and on the timing of the frame arrivals. In this paper the performance of EEE in terms of energy saving is evaluated. The results show that although EEE improves the energy efficiency, there is still potential for substantial further energy savings as in many cases most of the energy is wasted in waking up and sleeping the link.