Design and Analysis of MEC- and Proactive Caching-Based $360^{\circ }$ Mobile VR Video Streaming

Recently, 360-degree mobile virtual reality video (MVRV) has become increasingly popular because it can provide users with an immersive experience. However, MVRV is usually recorded in a high resolution and is sensitive to latency, which indicates that broadband, ultra-reliable, and low-latency communication is necessary to guarantee the users’ quality of experience. In this paper, we propose a mobile edge computing (MEC)-based 360-degree MVRV streaming scheme with field-of-view (FoV) prediction, which jointly considers video coding, proactive caching, computation offloading, and data transmission. To meet the requirement of stringent end-to-end (E2E) latency, the user’s viewpoint prediction is utilized to cache video data proactively, and computing tasks are partially offloaded to the MEC server. In addition, we propose an analytical model based on diffusion process to study the packet transmission process of 360-degree MVRV in multihop wired/wireless networks and analyze the performance of the MEC-enabled scheme. The simulation results verify the accuracy of the analysis and the effectiveness of the proposed MVRV streaming scheme in reducing the E2E delay. Furthermore, the analytical framework sheds some light on the impacts of system parameters, e.g., FoV prediction accuracy and transmission rate, on the balance between computation delay and communication delay.

I. Introduction

Mobile virtual reality (VR) is expected to become an extremely popular application on 5 G networks and refers to the transmission of video and sound files from a cloud server to a user’s terminal device via a multihop network in order to achieve storage and rendering by the cloud server or edge server in virtual reality business. For example, this application is practical with the aid of cloud computing technology and stable gigabit fiber networks [1]. A 360-degree video, which is also known as a three-degree-of-freedom (3-DoF) spherical video, can provide users with an immersive experience. Because 360-degree mobile virtual reality video (MVRV) combines the multiple requirements of high capacity of enhanced mobile broadband (eMBB) services and stringent latency and reliability of ultra-reliable low-latency communication (URLLC) services, there are currently many technical difficulties in supporting this application [2], [3]. Currently, research in this area focuses not only on traditional approaches including increasing the transmission rate or decreasing the bandwidth requirements but also on jointly utilizing the resources of caching, computation, communication (3 C) [4]–[6].