SOFA: A Sleep-Optimal Fair-Attention Scheduler for the Power-Saving Mode of WLANs
Mobile devices adopt the IEEE 802.11 PSM (Power-Saving Mode) scheme and its enhancements to reduce their energy consumption when using Wi-Fi interfaces. However, the capability of PSM to save energy is limited when the WLANs are highly congested by other Wi-Fi clients. In this paper, instead of further pursuing the trade-off between power saving and the incurred delay on the client side, the authors take a different approach and explore the energy saving potential by considering the scheduling policy on the Access Point (AP) side. They find that the traditional packet-level first-come-first-serve policy is not sleep optimal since it keeps the PSM clients awake unnecessarily.