No abstract

We present a new cross-layer ARQ algorithm for video streaming over 802.11 wireless networks. The algorithm combines application-level information about the perceptual and temporal importance of each packet into a single priority value, which drives packet selection at each retransmission opportunity. Hence, only the most most perceptually important packets are retransmitted, delivering higher perceptual quality and less bandwidth usage compared to the standard 802.11 MAC-layer ARQ scheme. H.264 video streaming based on the proposed technique has been simulated using ns in a realistic home network scenario, using the standard ARQ technique for all interfering traffic. Results show that the proposed method consistently outperforms the standard MAC-layer 802.11 retransmission scheme, delivering more than 1.5 dB PSNR gains using approximately half of the retransmission bandwidth.

No abstract

Cloud gaming enables playing high end games, originally designed for PC or game console setups, on low end devices, such as net-books and smartphones, by offloading graphics rendering to GPU powered cloud servers. However, transmitting the high end graphics requires a large amount of available network bandwidth, even though it is a compressed video stream. Foveated video encoding (FVE) reduces the bandwidth requirement by taking advantage of the non-uniform acuity of human visual system and by knowing where the user is looking. We have designed and implemented a system for cloud gaming with foveated graphics using a consumer grade real-time eye tracker and an open source cloud gaming platform. In this article, we describe the system and its evaluation through measurements with representative games from different genres to understand the effect of parameterization of the FVE scheme on bandwidth requirements and to understand its feasibility from the latency perspective. We also present results from a user study. The results suggest that it is possible to find a "sweet spot" for the encoding parameters so that the users hardly notice the presence of foveated encoding but at the same time the scheme yields most of the bandwidth savings achievable.