The wireless metaverse will create diverse user experiences at the intersection of the physical, digital, and virtual worlds. These experiences will enable novel interactions between the constituents (e.g., extended reality (XR) users and avatars) of the three worlds. However, remarkably, to date, there is no holistic vision that identifies the full set of metaverse worlds, constituents, and experiences, and the implications of their associated interactions on next-generation communication and computing systems. In this paper, we present a holistic vision of a limitless, wireless metaverse that distills the metaverse into an intersection of seven worlds and experiences that include the: i) physical, digital, and virtual worlds, along with the ii) cyber, extended, live, and parallel experiences. We then articulate how these experiences bring forth interactions between diverse metaverse constituents, namely, a) humans and avatars and b) connected intelligence systems and their digital twins (DTs). Then, we explore the wireless, computing, and artificial intelligence (AI) challenges that must be addressed to establish metaverse-ready networks that support these experiences and interactions. We particularly highlight the need for end-to-end synchronization of DTs, and the role of human-level AI and reasoning abilities for cognitive avatars. Moreover, we articulate a sequel of open questions that should ignite the quest for the future metaverse. We conclude with a set of recommendations to deploy the limitless metaverse over future wireless systems.

翻译：无线元宇宙将在物理、数字和虚拟世界的交汇处创造出多样化的用户体验。这些体验将使得三个世界的构成要素（例如扩展现实用户和虚拟化身）之间产生新型交互。然而值得注意的是，迄今为止仍缺乏一个整体性愿景来全面描述元宇宙世界、构成要素与体验的完整集合，及其相关交互对下一代通信与计算系统的影响。本文提出一个关于无界无线元宇宙的整体愿景，将元宇宙凝练为七个世界与体验的交汇：i）物理世界、数字世界和虚拟世界，以及ii）网络体验、扩展体验、实时体验与平行体验。继而阐述这些体验如何催生不同元宇宙构成要素之间的交互，具体包括：a）人类与虚拟化身，b）连接智能系统及其数字孪生。随后探讨为实现支持这些体验与交互的元宇宙就绪网络，必须应对的无线通信、计算与人工智能挑战。我们特别强调数字孪生端到端同步的必要性，以及人类级人工智能与推理能力对认知虚拟化身的作用。此外，系统阐述一系列有待解决的开放问题，以激发未来元宇宙的研究探索。最后提出在下一代无线系统上部署无界元宇宙的相关建议。