Wireless Adapter Sleep Scheduling Based on Video QoE: How to Improve Battery Life When Watching Streaming Video?

Power management is a critical issue for mobile devices, where a significant portion of the total system energy can be often consumed by heavy wireless network activity. In this paper we present a framework that reduces the energy consumption of wireless mobile devices during streaming video content over Wireless LAN networks by utilizing the power saving mechanisms defined in the IEEE 802.11e standard. The framework allows video applications to directly optimize the overall energy efficiency by controlling the sleep cycles of wireless network adapters based on video QoE. The framework employs a simple QoE estimation algorithm that estimates the user level video quality, and adjusts the sleep intervals of the wireless adapter to maintain video quality while maximizing power efficiency. As an important part of our paper the building and configuration steps of a working testbed system is carefully described, which demonstrates the availability and efficiency of the U-APSD power saving technology at hand. A preliminary evaluation of the proposed framework supports that by enabling the WMM Power Saving feature 20-30% of total system energy can be saved even in case of asynchronous video traffic.