Cross-layer energy Optimization for Dynamic Video Streaming over Wi-Fi
Zhang Zhi, Mehmet Karaca, Farnaz Moradi, Saeed Bastani, Anders Nilsson Plymoth, Rickard Ljung, Björn Landfeldt · Lund University Publications (Lund University) · 2016
Dynamic Adaptive Streaming over HTTP (DASH)constitutes a large fraction of traffic in the mobile Internet.Mobile devices often use video delivery over Wi-Fi, which is asignificant energy drain. Dynamic Power Saving Mode (DPSM)is one of the most widely-used approaches for Wi-Fi devices tosave power and shorten packet delay. However, DPSM uses afixed timeout before a device goes to sleep, leading to excessiveenergy use in many cases. In this paper, we propose a crosslayer lightweight dynamic timeout adjustment algorithm. Theapplication layer measures the Round-Trip Time (RTT) of videosegments in the current timeout setup, determines an updatedtimeout, sets it to the medium access control layer and requeststhe next video quality based on the RTT and RTT change.We evaluate our algorithm via simulations in OMNeT++ andshow that compared with the legacy Wi-Fi DPSM for DASH,our algorithm reduces the average power consumption in theradio front end while significantly improving the fairness amongusers. Moreover, the new algorithm retains video quality whileachieving better energy efficiency. The improvement increases insignificance with increasing number of users, which means thatthe new algorithm works well in dense scenarios.