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Since the popularisation of the Internet in the 1990s, the cyberspace has kept evolving. We have created various computer-mediated virtual environments including social networks, video conferencing, virtual 3D worlds (e.g., VR Chat), augmented reality applications (e.g., Pokemon Go), and Non-Fungible Token Games (e.g., Upland). Such virtual environments, albeit non-perpetual and unconnected, have bought us various degrees of digital transformation. The term `metaverse' has been coined to further facilitate the digital transformation in every aspect of our physical lives. At the core of the metaverse stands the vision of an immersive Internet as a gigantic, unified, persistent, and shared realm. While the metaverse may seem futuristic, catalysed by emerging technologies such as Extended Reality, 5G, and Artificial Intelligence, the digital `big bang' of our cyberspace is not far away. This survey paper presents the first effort to offer a comprehensive framework that examines the latest metaverse development under the dimensions of state-of-the-art technologies and metaverse ecosystems, and illustrates the possibility of the digital `big bang'. First, technologies are the enablers that drive the transition from the current Internet to the metaverse. We thus examine eight enabling technologies rigorously - Extended Reality, User Interactivity (Human-Computer Interaction), Artificial Intelligence, Blockchain, Computer Vision, IoT and Robotics, Edge and Cloud computing, and Future Mobile Networks. In terms of applications, the metaverse ecosystem allows human users to live and play within a self-sustaining, persistent, and shared realm. Therefore, we discuss six user-centric factors -- Avatar, Content Creation, Virtual Economy, Social Acceptability, Security and Privacy, and Trust and Accountability. Finally, we propose a concrete research agenda for the development of the metaverse.
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All One Needs to Know about Metaverse: A
Complete Survey on Technological Singularity,
Virtual Ecosystem, and Research Agenda
Lik-Hang Lee1, Tristan Braud2, Pengyuan Zhou3,4, Lin Wang1, Dianlei Xu6, Zijun Lin5, Abhishek Kumar6,
Carlos Bermejo2, and Pan Hui2,6,Fellow, IEEE,
Abstract—Since the popularisation of the Internet in the 1990s,
the cyberspace has kept evolving. We have created various
computer-mediated virtual environments including social net-
works, video conferencing, virtual 3D worlds (e.g., VR Chat),
augmented reality applications (e.g., Pokemon Go), and Non-
Fungible Token Games (e.g., Upland). Such virtual environments,
albeit non-perpetual and unconnected, have bought us various
degrees of digital transformation. The term ‘metaverse’ has
been coined to further facilitate the digital transformation in
every aspect of our physical lives. At the core of the metaverse
stands the vision of an immersive Internet as a gigantic, unified,
persistent, and shared realm. While the metaverse may seem
futuristic, catalysed by emerging technologies such as Extended
Reality, 5G, and Artificial Intelligence, the digital ‘big bang’ of
our cyberspace is not far away.
This survey paper presents the first effort to offer a compre-
hensive framework that examines the latest metaverse develop-
ment under the dimensions of state-of-the-art technologies and
metaverse ecosystems, and illustrates the possibility of the digital
‘big bang’. First, technologies are the enablers that drive the
transition from the current Internet to the metaverse. We thus
examine eight enabling technologies rigorously - Extended Real-
ity, User Interactivity (Human-Computer Interaction), Artificial
Intelligence, Blockchain, Computer Vision, IoT and Robotics,
Edge and Cloud computing, and Future Mobile Networks. In
terms of applications, the metaverse ecosystem allows human
users to live and play within a self-sustaining, persistent, and
shared realm. Therefore, we discuss six user-centric factors –
Avatar, Content Creation, Virtual Economy, Social Acceptability,
Security and Privacy, and Trust and Accountability. Finally, we
propose a concrete research agenda for the development of the
metaverse.
Index Terms—Metaverse, Immersive Internet,
Augmented/Virtual Reality, Avatars, Artificial Intelligence,
Digital Twins, Networking and Edge Computing, Virtual
Economy, Privacy and Social Acceptability.
I. INT ROD UC TI ON
METAVERSE, combination of the prefix “meta” (imply-
ing transcending) with the word “universe”, describes
a hypothetical synthetic environment linked to the physical
world. The word ‘metaverse’ was first coined in a piece
of speculative fiction named Snow Crash, written by Neal
Stephenson in 1992 [1]. In this novel, Stephenson defines
the metaverse as a massive virtual environment parallel to
Corresponding Authors: Lik-Hang Lee, E-mail: (likhang.lee@kaist.ac.kr)
1KAIST, South Korea; 2HKUST, Hong Kong SAR; 3USTC China; 4
MCT Key Lab of CCCD; 5UCL, UK; 6Uni. Helsinki, Finland.
Manuscript submitted in October 2021.
Fig. 1. We propose a ‘digital twins-native continuum’, on the basis
of duality. This metaverse vision reflects three stages of development. We
consider the digital twins as a starting point, where our physical environments
are digitised and thus own the capability to periodically reflect changes to their
virtual counterparts. According to the physical world, digital twins create
digital copies of the physical environments as ‘many’ virtual worlds, and
human users with their avatars work on new creations in such virtual worlds,
as digital natives. It is important to note that such virtual worlds will initially
suffer from limited connectivity with each other and the physical world,
i.e., information silo. They will then gradually connect within a massive
landscape. Finally, the digitised physical and virtual worlds will eventually
merge, representing the final stage of the co-existence of physical-virtual
reality similar to the surreality). Such a connected physical-virtual world give
rise to the unprecedented demands of perpetual and 3D virtual cyberspace as
the metaverse.
the physical world, in which users interact through digi-
tal avatars. Since this first appearance, the metaverse as a
computer-generated universe has been defined through vastly
diversified concepts, such as lifelogging [2], collective space
in virtuality [3], embodied internet/ spatial Internet [4], a
mirror world [5], an omniverse: a venue of simulation and
collaboration [6]. In this paper, we consider the metaverse as
a virtual environment blending physical and digital, facilitated
by the convergence between the Internet and Web technolo-
gies, and Extended Reality (XR). According to the Milgram
and Kishino’s Reality-Virtuality Continuum [7], XR integrates
digital and physical to various degrees, e.g., augmented reality
(AR), mixed reality (MR), and virtual reality (VR). Similarly,
the metaverse scene in Snow Crash projects the duality of
the real world and a copy of digital environments. In the
metaverse, all individual users own their respective avatars, in
analogy to the user’s physical self, to experience an alternate
life in a virtuality that is a metaphor of the user’s real worlds.
To achieve such duality, the development of metaverse
has to go through three sequential stages, namely (I) digital
twins, (II) digital natives, and eventually (III) co-existence
of physical-virtual reality or namely the surreality. Figure 1
depicts the relationship among the three stages. Digital twins
refer to large-scale and high-fidelity digital models and entities
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Fig. 2. The cyberspace landscape of real-life applications, where superseding relationships exists in the information richness theory (left-to-right) as well as
transience-permanence dimension (bottom-to-top).
duplicated in virtual environments. Digital twins reflect the
properties of their physical counterparts [8], including the
object motions, temperature, and even function. The con-
nection between the virtual and physical twins is tied by
their data [9]. The existing applications are multitudinous
such as computer-aided design (CAD) for product design
and building architectures, smart urban planning, AI-assisted
industrial systems, robot-supported risky operations [10]–[14].
After establishing a digital copy of the physical reality, the
second stage focuses on native content creation. Content
creators, perhaps represented by the avatars, involve in digital
creations inside the digital worlds. Such digital creations can
be linked to their physical counterparts, or even only exist in
the digital world. Meanwhile, connected ecosystems, including
culture, economy, laws, and regulations (e.g, data ownership),
social norms, can support these digital creation [15]. Such
ecosystems are analogous to real-world society’s existing
norms and regulations, supporting the production of physical
goods and intangible contents [16]. However, research on such
applications is still in a nascent stage, focusing on the first-
contact point with users, such as input techniques and author-
ing system for content creation [17]–[20]. In the third and
final stage, the metaverse could become a self-sustaining and
persistent virtual world that co-exists and interoperates with
the physical world with a high level of independence. As such,
the avatars, representing human users in the physical world,
can experience heterogeneous activities in real-time charac-
terised by unlimited numbers of concurrent users theoretically
in multiple virtual worlds [9]. Remarkably, the metaverse
can afford interoperability between platforms representing
different virtual worlds, i.e., enabling users to create contents
and widely distribute the contents across virtual worlds. For
instance, a user can create contents in a game, e.g., Minecraft1,
and transfer such contents into another platform or game, e.g.,
Roblox2, with a continued identity and experience. To a further
extent, the platform can connect and interact with our physical
world through various channels, user’s information access
through head-mounted wearable displays or mobile headsets
(e.g. Microsoft Hololens3), contents, avatars, computer agents
in the metaverse interacting with smart devices and robots, to
name but a few.
According to the diversified concepts of computer-mediated
universe(s) mentioned above, one may argue that we are
already situated in the metaverse. Nonetheless, this is only
partially correct, and we examine several examples to jus-
tify our statement with the consideration of the three-stage
metaverse development roadmap. The Earth 3D map4offers
picture frames of the real-world but lacks physical properties
other than GPS information, while social networks allow users
to create contents but limited to texts, photos, and videos
with limited options of user engagements (e.g., liking a post).
Video games are getting more and more realistic and impres-
sive. Users can experience outstanding graphics with in-game
physics, e.g., Call of Duty: Black Ops Cold War, that deliver a
sense of realism that resembles the real world in great details.
A remarkable example of an 18-year-old virtual world, Second
Life5, is regarded as the largest user-created 3D Universe.
Users can build and shape their 3D environments and live
in such a virtual world extravagantly. However,video games
still lack interoperability between each other. The emerging
1https://www.minecraft.net/en-us
2https://www.roblox.com/
3https://www.microsoft.com/en-us/hololens
4https://earth3dmap.com/
5https://id.secondlife.com