Due to the widespread adoption of "work-from-home" policies, videoconferencing applications (e.g., Zoom) have become indispensable for remote communication. However, these systems lack immersiveness, leading to the so-called "Zoom fatigue" and degrading communication efficiency. The recent debut of Apple Vision Pro, a mixed reality headset that supports "spatial persona", aims to offer an immersive telepresence experience with these applications. In this paper, we conduct a first-of-its-kind in-depth and empirical study to analyze the performance of immersive telepresence with four applications, Apple FaceTime, Cisco Webex, Microsoft Teams, and Zoom, on Vision Pro. We find that only FaceTime provides a truly immersive experience with spatial personas, whereas other applications still operate 2D personas. Our measurement results reveal that (1) FaceTime delivers semantic information to optimize bandwidth consumption, which is even lower than that of 2D persona for other applications, and (2) it employs visibility-aware optimizations to reduce rendering overhead. However, the scalability of FaceTime remains limited, with a simple server allocation strategy that potentially leads to high network delay among users.

翻译：受“居家办公”政策的普及影响，视频会议应用（如 Zoom）已成为远程沟通不可或缺的工具。然而，这些系统缺乏沉浸感，导致所谓“Zoom疲劳”现象，并降低通信效率。随着支持“空间化身”的混合现实头显设备苹果 Vision Pro 的近期问世，其旨在通过相关应用提供沉浸式远程呈现体验。本文首次开展深入实证研究，分析 Vision Pro 上四款应用（苹果 FaceTime、思科 Webex、微软 Teams 及 Zoom）的沉浸式远程呈现性能。我们发现仅 FaceTime 能通过空间化身提供真正沉浸式体验，而其他应用仍采用二维化身模式。测量结果表明：(1) FaceTime 通过传递语义信息优化带宽消耗，其带宽甚至低于其他应用的二维化身模式；(2) 该应用采用可见性感知优化以减少渲染开销。然而，FaceTime 的可扩展性仍受限于简单的服务器分配策略，可能导致用户间产生较高的网络延迟。