🤖 AI Summary
This work addresses the challenge of ultra-low motion-to-photon (MTP) latency in immersive volumetric video for extended reality (XR), where conventional edge architectures struggle to meet the stringent real-time demands arising from tight coupling between high-compute rendering and user motion. The authors propose a near-real-time streaming framework based on O-RAN that jointly orchestrates wireless, computing, and content resources. By optimizing the rendered pixel ratio through continuous control variables under constraints of O-Cloud compute capacity, gNB transmit power, and bandwidth, the framework holistically balances resolution, computational load, and latency. A novel integration of the Weber-Fechner perceptual model guides QoE-aware optimization, complemented by structured action decomposition and a QoE-sensitive reward mechanism to tackle high-dimensional control complexity. Experiments on a 5G O-RAN testbed and simulations demonstrate over an 11% reduction in median MTP latency, along with significant improvements in average QoE and user experience fairness.
📝 Abstract
Immersive volumetric video streaming in extended reality (XR) demands ultra-low motion-to-photon (MTP) latency, which conventional edge-centric architectures struggle to meet due to per-frame computationally intensive rendering tightly coupled with user motion. To address this challenge, we propose an Open Radio Access Network (O-RAN)-integrated playback framework that jointly orchestrates radio, compute, and content resources in near real time (Near-RT) control loop. The system formulates the rendered-pixel ratio as a continuous control variable and jointly optimizes it over the Open Cloud (O-Cloud) compute, gNB transmit power, and bandwidth under a Weber-Fechner quality of experience (QoE) model, explicitly balancing resolution, computation, and latency. A Soft Actor-Critic (SAC) agent with structured action decomposition and QoE-aware reward shaping resolves the resulting high-dimensional control problem. Experiments on a 5G O-RAN testbed and system simulations show that SAC reduces median MTP latency by above $11\%$ and improves both mean QoE and fairness, demonstrating the feasibility of RIC-driven joint radio-compute-content control for scalable, latency-aware immersive streaming.