I. Introduction
In this paper, we revisit a number of classical network scheduling problems and examine how they are affected when we introduce energy awareness. Most such scheduling problems have been formulated under the assumption that the processing rate of a server is fixed. However, the modern trend is to allow dynamic adjustment of processing rate of a server because operating at a lower rate typically requires less power. This has inspired a growing body of research on how to best take advantage of this so-called rate adaptation capability in the interest of maximizing energy savings. However, a growing body of research has been motivated by the fact that the energy usage of a server is determined by its servicing rate. Hence, we can reduce the energy usage of a network by sometimes running the servers at slower rates. For example, one common assumption is that the power required to run a server at rate scales as for some .