the trend solutions in this paper target both objectives. these solutions are presented from the device, the architecture and the network points of view and they span the access, metro and core network segments. In section II, we discuss approaches that reduce the power consumption of individual systems or components. In Section III we consider those approaches that require more profound changes in the network architecture. In Section IV we present approaches that improve the scaling of power to the actual traffic. Finally,in section V we wrap up with the expected energy savings of these approaches, and discuss a number of important open issues.