E2WFQ: an energy efficient fair scheduling policy for wireless systems

As embedded systems are being networked, often wirelessly, an increasingly larger share of their total energy budget is due to the communication. This necessitates the development of power management techniques that address communication subsystems, such as radios, as opposed to computation subsystems, such as embedded processors, to which most of the research effort thus far has been devoted. In this paper, we present E²WFQ, an energy efficient version of the weighted fair queuing (WFQ) algorithm for packet scheduling in communication systems. We employ a recently proposed radio power management technique, dynamic modulation scaling (DMS), as a control knob to enable energy-latency tradeoffs during wireless packet scheduling. The use of E²WFQ results in an energy aware packet scheduler, which exploits the statistics of the input arrival pattern as well as the variability in packet lengths. Simulation results show that large savings in energy consumption can be obtained through the use of our scheduling scheme, compared to conventional WFQ, with only a small, bounded increase in worst case packet latency.