QoE-Aware Coordinated Caching for Adaptive Video Streaming in High-speed Railways

In this paper, we investigate a QoE-aware coordinated caching scheme to adaptively satisfy the diversified video streaming requirements in a high-speed railway network, which consists of multiple cells endowed with cache storage capacity. However, traditional QoS-based video streaming schemes may not accurately reflect the influence of video adaption on user satisfaction. What's more, dynamic user demands and frequent handover impose serious challenges in terms of unknown uncertainties and short dwelling time. To overcome these challenges, we first define a perceptual QoE considering both video quality and video stalling. Second, we formulate a long-term optimization problem to maximize the perceptual QoE, with the cache storage and system stability constraints. Then, we propose a distributed online algorithm based on the Lyapunov optimization theory, which does not require future system information and is efficient for implementation. Finally, theoretical analysis and simulation results are presented to validate the effectiveness of the proposed algorithm.