Edge-assisted rendering of 360◦ videos streamed to head-mounted virtual reality

Abstract

Over the past years, 360◦ video streaming is getting popular. Watching these videos with Head-Mounted Displays (HMDs), also known as Virtual Reality (VR) headsets, gives more immersive experience than using traditional planar monitors. To fulfill a real immersive experience, there are several challenges, such as high bandwidth consumption, latency-sensitive, and heterogeneous HMD devices. In this paper, we propose an edge-assisted 360◦ video streaming system, which leverages edge servers to render viewports for viewers of 360◦ videos. We formulate an optimization problem to determine which HMD clients should be served by the edge server. We design an algorithm to solve this problem, and implement a real testbed as a proof-of-concept. The resulting edge-assisted 360◦ video streaming system is extensively evaluated with a public 360◦ viewing dataset. Leveraging edge servers, we reduce the bandwidth usage and computational workload on HMD clients. Moreover, lower network latency is achieved. The evaluation results show that compared to current 360◦ video streaming platforms, our edge-assisted rendering platform: (i) saves up to 62% in bandwidth consumption, (ii) achieves higher viewing quality, (iii) reduces the computation workload for those lightweight HMDs, and (iv) saves the battery life of HMD clients.