EVB360: Efficient 360-Degree Video Broadcast in Next-Generation Cellular Networks

We propose EVB360, an efficient 360° video broadcast scheme for next-generation NR-MBMS (5G New Radio MBMS) cellular networks. EVB360 employs a dynamic broadcast area definition, adaptive 360-degree video encoding, and tiled transmission using optimized transmission parameters. We define broadcast areas by using K-means clustering and then proportionally assign resources to broadcast adaptively the encoded tiles. EVB360 ensures high level of immersive video broadcast streaming quality to a higher number of served users. Adaptive encoding of 360° video tiles and radio resource (modulation-coding, subframe) allocation is governed by user viewing angle, content request, position, and received signal strength. Our experiments show that our solution enables considerable gains in viewport PSNR (57.44%) and number of served users (72.19%), over a recent state-of-the-art method VRCAST.

I. Introduction

Immersive 360° video streaming is increasingly used in diverse applications such as virtual reality, gaming, and entertainment [1]. In the immersive environment, a viewer changes her viewing direction and the content is accordingly rendered. However, streaming such content requires very high bandwidth and is challenging [1]. A 360-degree video can be spatially divided into small portions called tiles that can be encoded at different quality levels. This has enabled tiling-based viewport-adaptive 360° video streaming, where tiles are delivered to clients based on their viewing direction and network conditions. Concretely, the viewport tiles are delivered at high quality and the rest are sent at lower quality [2].