[Paper Review] Towards a Decentralized Metaverse: Synchronized Orchestration of Digital Twins and Sub-Metaverses

Omar Hashash, Christina Chaccour+3 more|arXiv (Cornell University)|Nov 26, 2022

Modular Robots and Swarm Intelligence4 citations

TL;DR

This paper proposes a decentralized metaverse framework that synchronously orchestrates digital twins (DTs) and sub-metaverses at the wireless edge using optimal transport theory. By jointly allocating computing and communication resources, the framework reduces sub-synchronization time by 25.75% compared to SNR-based association, enabling real-time, high-fidelity digital replicas of physical environments and their autonomous systems.

ABSTRACT

Accommodating digital twins (DTs) in the metaverse is essential to achieving digital reality. This need for integrating DTs into the metaverse while operating them at the network edge has increased the demand for a decentralized edge-enabled metaverse. Hence, to consolidate the fusion between real and digital entities, it is necessary to harmonize the interoperability between DTs and the metaverse at the edge. In this paper, a novel decentralized metaverse framework that incorporates DT operations at the wireless edge is presented. In particular, a system of autonomous physical twins (PTs) operating in a massively-sensed zone is replicated as cyber twins (CTs) at the mobile edge computing (MEC) servers. To render the CTs' digital environment, this zone is partitioned and teleported as distributed sub-metaverses to the MEC servers. To guarantee seamless synchronization of the sub-metaverses and their associated CTs with the dynamics of the real world and PTs, respectively, this joint synchronization problem is posed as an optimization problem whose goal is to minimize the average sub-synchronization time between the real and digital worlds, while meeting the DT synchronization intensity requirements. To solve this problem, a novel iterative algorithm for joint sub-metaverse and DT association at the MEC servers is proposed. This algorithm exploits the rigorous framework of optimal transport theory so as to efficiently distribute the sub-metaverses and DTs, while considering the computing and communication resource allocations. Simulation results show that the proposed solution can orchestrate the interplay between DTs and sub-metaverses to achieve a 25.75 % reduction in the sub-synchronization time in comparison to the signal-to-noise ratio-based association scheme.

Motivation & Objective

• To address the challenge of synchronizing real-world physical twins (PTs) and their digital twins (DTs) with distributed sub-metaverses in a decentralized, edge-enabled metaverse architecture.
• To minimize the sub-synchronization time between physical regions and their digital replicas while satisfying DT synchronization intensity constraints.
• To jointly optimize the association of sub-metaverses and DTs with mobile edge computing (MEC) servers, considering both communication and computing resource allocation.
• To enable seamless, real-time interoperability between autonomous physical systems and their digital counterparts in a scalable, distributed metaverse environment.

Proposed method

• Models the physical zone as a 3D space partitioned into infinitesimal volumes, each represented as a sub-metaverse at an MEC server.
• Represents each physical twin (PT) as a cyber twin (CT) in the digital domain, with synchronization delay modeled as the sum of communication and computing delays.
• Formulates the joint sub-metaverse and DT association problem as an optimization task to minimize average sub-synchronization time.
• Applies optimal transport theory to efficiently distribute sub-metaverses and DTs across MEC servers while respecting resource constraints.
• Derives delay models: $ t^{ ext{sync}}_{q,b} = t^{ ext{com}}_{q,b} + t^{ ext{cmp}}_{q,b} $, combining data transmission and rendering times.
• Uses iterative algorithms based on optimal transport to solve the joint association and resource allocation problem under QoS and resource constraints.

Experimental results

Research questions

• RQ1 How can sub-metaverses and digital twins be jointly orchestrated across edge servers to minimize synchronization delay in a decentralized metaverse?
• RQ2 What is the optimal distribution of sub-metaverses and digital twins across MEC servers to maintain real-time fidelity with physical systems?
• RQ3 How can communication and computing resources be jointly allocated to meet synchronization intensity requirements of digital twins?
• RQ4 To what extent can optimal transport theory improve the efficiency of sub-metaverse and DT assignment compared to conventional association schemes?
• RQ5 What performance gain is achievable in sub-synchronization time through joint optimization of sub-metaverse and DT placement?

Key findings

• The proposed framework reduces sub-synchronization time by 25.75% compared to a signal-to-noise ratio (SNR)-based association scheme.
• Optimal transport-based joint association of sub-metaverses and digital twins achieves superior synchronization performance by balancing load and minimizing end-to-end delay.
• The framework effectively handles the trade-off between communication and computing delays, ensuring real-time synchronization for high-intensity digital twins.
• The method supports scalable deployment of a decentralized metaverse by distributing workloads across multiple edge servers.
• Simulation results confirm that the proposed algorithm maintains synchronization fidelity under varying network and computational conditions.
• The solution enables seamless interoperability between autonomous physical systems and their digital twins in a distributed, edge-native metaverse architecture.