Adaptive Fidelity and Event-triggered Synchronization for Real-time Digital Twins over Constrained IoT Networks
Keywords:
Adaptive fidelity, Age of Digital Twin, Age of information, Bandwidth optimization, Digital Twin, Energy efficiency, Event-triggered synchronization, IoT, Real-time systems, Smart cityAbstract
Real-time Digital Twins (DTs) for IoT and smart city systems require timely and resource-efficient synchronization between physical entities and their virtual counterparts over bandwidth- and energy-constrained networks. This study formulates the Age of Digital Twin (AoDT) as a freshness metric that captures the staleness of twin states under communication and computation delays, extending classical Age of Information (AoI) concepts to cyber-physical DT pipelines. The work compares periodic and event-triggered synchronization policies and proposes adaptive fidelity mechanisms that jointly tune sampling rates, model granularity, and transmission thresholds as a function of AoDT network load and device energy budgets. Analytical insights and qualitative evaluations show that threshold-based event-triggered policies can significantly reduce bandwidth and energy consumption while maintaining acceptable AoDT bounds, particularly in slowly varying processes and under bursty network conditions. Conversely, periodic updates provide predictability and simpler resource provisioning but can be suboptimal under heterogeneous traffic and non-stationary dynamics. The study synthesizes results from AoI theory, event-triggered control, and DT architectures to derive design guidelines for real-time DT deployments in smart city scenarios, including hybrid AoDT- and state-based triggers, multi-priority scheduling across fleets of twins, and cross-layer adaptation of fidelity and communication policies.
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