Reconsidering power management

Power-management approaches have been widely studied in an attempt to conserve idling energy by allowing nodes to switch to a low-power sleep mode. However, due to the inherent inability of current approaches to match sleep schedules to different traffic patterns, energy is wasted switching needlessly from sleep to idle or large delays in traffic delivery are incurred due to being in the sleep state too long. In this paper, we explore such effects of various traffic patterns on current power management protocols. Our results show the importance of traffic information to obtain larger benefits from power management. While some proposals that exploit traffic information exist, they rely primarily on individual sender traffic patterns to develop sleep schedules, ignoring aggregate traffic observed by receivers. This deficiency motivates the design of a new power management protocol that use traffic information at the receivers to adapt sleep schedules.