VR/AR Immersive Communication: Caching, Edge Computing, and Transmission Trade-Offs

We study the delivery of 360°-navigable videos to 5G VR/AR wireless clients in future cooperative multi-cellular systems. A collection of small-cell base stations interconnected via back-haul links are sharing their caching and computing resources to maximize the aggregate reward they earn by serving 360° videos requested by VR/AR wireless clients. We design an efficient representation method to construct the 360° videos such that they only deliver the remote scene viewpoint content genuinely needed by the VR/AR user, thereby overcoming the present highly inefficient approach of sending a bulky 360° video, whose major part comprises scene information never accessed by the user. Moreover, we design an optimization framework that allows the base stations to select cooperative caching/rendering/streaming strategies that maximize the aggregate reward they earn when serving the users, for the given caching/computational resources at each base station. We formulate the problem of interest as integer programming, show its NP-hardness, and derive a fully-polynomial-time approximation solution with strong performance guarantees. Our advances demonstrate orders of magnitude operational efficiency gains over state-of-the-art caching and 360° video representation mechanisms and are very promising. This is a first-of-its-kind study to explore fundamental trade-offs between caching, computing, and communication for emerging VR/AR applications of broad societal impact.