Optimizing QoE-Privacy Tradeoff for Proactive VR Streaming
Xing Wei, Shengqian Han, Chenyang Yang, Chengjian Sun
TL;DR
This work tackles privacy in proactive VR streaming, where uploading predicted viewpoints and prediction errors risks leaking users' actual viewpoints. It first analyzes viewpoint leakage under existing privacy-preserving data processing and proves that leakage cannot be eliminated due to the PEA relation, yielding a positive lower bound Pr(A)min = ε/π. To overcome this, it introduces B-PEA, which breaks the PEA relation by adding noise n to the prediction errors, and derives the optimal noise strategy that minimizes QoE loss subject to Pr(A) ≤ q, even under worst-case distributions of the prediction error e. A trace-driven evaluation on real VR workloads shows that B-PEA satisfies privacy constraints for all users and substantially improves QoE compared with Gaussian or Laplace baselines, with negligible QoE loss when zero leakage is enforced. Overall, the paper provides a principled framework for zero-leakage privacy in proactive VR streaming and demonstrates practical gains in both privacy guarantees and user QoE.
Abstract
Proactive virtual reality (VR) streaming requires users to upload viewpoint-related information, raising significant privacy concerns. Existing strategies preserve privacy by introducing errors to viewpoints, which, however, compromises the quality of experience (QoE) of users. In this paper, we first delve into the analysis of the viewpoint leakage probability achieved by existing privacy-preserving approaches. We determine the optimal distribution of viewpoint errors that minimizes the viewpoint leakage probability. Our analyses show that existing approaches cannot fully eliminate viewpoint leakage. Then, we propose a novel privacy-preserving approach that introduces noise to uploaded viewpoint prediction errors, which can ensure zero viewpoint leakage probability. Given the proposed approach, the tradeoff between privacy preservation and QoE is optimized to minimize the QoE loss while satisfying the privacy requirement. Simulation results validate our analysis results and demonstrate that the proposed approach offers a promising solution for balancing privacy and QoE.
