Qoe-Aware Scheduling For Video Streaming In 802.11n/Ac-Based High User Density Networks

The provision of Quality of Experience (QoE) for wireless video streaming has become a necessity. From this perspective, we design a QoE-aware scheduling (QoEAS) scheme for video streaming over IEEE 802.11n/ac networks. We consider an application scenario where videos are streamed in an area with high density of users. To improve the streamed video quality, we enhance the conventional gradient based scheduling scheme (U'R) by incorporating the packet delay and channel transmission rate with video packet importance index in scheduling. This index is derived based on the gradient of the QoE function for video, which accurately reflects the usefulness of a packet in enhancing the video quality. To be compatible to practical networks such as IEEE 802.11n/ac, the packet importance index is embedded in the Type-of-Service (ToS) field of IP header and is employed at Media Access Control (MAC) layer to perform scheduling. The proposed QoEAS significantly enhances the streamed video quality and achieves good fairness among users. It surpasses the conventional scheme by as much as 5 dB in Peak Signal-to-Noise Ratio (PSNR) at the lower 10 percentile of the users. To demonstrate the superiority and practicability of QoEAS, we also set up a lab test bed on a real 802.11ac network. Compared to conventional schemes, the proposed QoEAS shows notable QoE enhancement in lab test.