Optimal Multicast of Tiled 360 VR Video

TL;DR

This paper develops optimal multicast strategies for tiled 360 VR video, optimizing transmission parameters to minimize energy or maximize quality under various constraints, with globally optimal solutions and practical insights.

Contribution

It provides the first globally optimal closed-form solutions for non-convex multicast optimization problems in tiled 360 VR video delivery.

Findings

Optimal solutions reduce energy consumption for given quality.

Encoding rate adjustment enhances received video quality.

Numerical results validate the effectiveness of the proposed solutions.

Abstract

In this letter, we study optimal multicast of tiled 360 virtual reality (VR) video from one server (base station or access point) to multiple users. We consider random viewing directions and random channel conditions, and adopt time division multiple access (TDMA). For given video quality, we optimize the transmission time and power allocation to minimize the average transmission energy. For given transmission energy budget, we optimize the transmission time and power allocation as well as the encoding rate of each tile to maximize the received video quality. These two optimization problems are challenging non-convex problems. We obtain globally optimal closed-form solutions of the two non-convex problems, which reveal important design insights for multicast of tiled 360 VR video. Finally, numerical results demonstrate the advantage of the proposed solutions.