Ebublio: Edge-Assisted Multiuser 360° Video Streaming

As one of the most important manifestations of virtual reality (VR), 360° panoramic videos in recent years have experienced booming development due to the desire for immersive and interactive experiences. Compared to traditional videos, 360° videos are featured with uncertain user Field of View (FoV), more sensitive delay tolerance, and much higher bandwidth requirement, bringing unprecedented challenges to 360° video streaming. Meanwhile, the development of 5G and mobile edge computing starts to pave the way for high-bandwidth low-latency video streaming. Some preliminary works focus on either individual FoV prediction or multiuser Quality of Experience (QoE) oriented cache strategy design, while how to design a holistic solution toward optimizing the overall user QoE with considerations over fairness and long-term system cost remains a nontrivial problem. In this article, we propose Ebublio, a novel intelligent edge caching framework to address the aforementioned challenges in 360° video streaming. Ebublio consists of a collaborative FoV prediction (CFP) module and a long-term tile caching optimization (LTO) module to jointly optimize the long-term user QoE and system cost. The former module integrates the features of video content, user trajectory, and other users’ records for combined prediction. The latter one employs the Lyapunov framework and a subgradient optimization approach toward the optimal caching replacement policy. Our trace-driven evaluation demonstrates the superiority of our framework, with about 42% improvement in FoV prediction, and 36% improvement in QoE at similar traffic consumption.

I. Introduction

Recent years have witnessed the booming development of virtual reality (VR), which provides users an immersive and interactive experience to enjoy the virtual world. As one of the most important manifestations, 360° videos bring a new watching experience that has been widely adopted in many multimedia applications, such as gaming, education, tourism, and sports. It is also a key technology that supports the development of the new paradigm Metaverse. Cisco Mobile visual networking index (VNI) Forecast [1] indicates that 360° videos mobile data traffic will grow nearly 12-fold from 2017 to 2022. According to a recent market research report published on Globe Newswire [2], the global market size was USD 4.42 billion in 2020, exhibiting a significant growth of 42.2% compared to the average year-on-year growth during 2017–2019. They also predict that the market is projected to grow to USD 84.09 billion in 2028 at a compound annual growth rate (CAGR) of 44.8% in the 2021–2028 period.