Network Digital Twins for High-Performance Computing

This talk outlines a holistic framework for network digital twins (NDTs) in high-performance computing, covering construction, optimization, and application. The approach integrates federated learning for privacy-preserving model updates and reinforcement learning for closed-loop control, enabling real-time adaptation to traffic and system dynamics. Topics Covered HPC network digital twin construction: topology and telemetry ingestion, calibration Distributed and regional twin orchestration Federated learning for privacy-preserving NDT updates Reinforcement learning for closed-loop HPC network control Case studies: workload forecasting, congestion-aware routing, anomaly detection Portability to edge and 6G-class environments Links Workshop Program

November 2025 · Z. Zhang

Digital Network Twins for Next-Generation Wireless: Creation, Optimization, and Challenges

Download Paper arXiv Abstract Digital network twins (DNTs), by representing a physical network using a virtual model, offer significant benefits such as streamlined network development, enhanced productivity, and cost reduction for next-generation (nextG) communication infrastructure. Existing works mainly describe the deployment of DNT technologies in various service sections. The full life cycle of DNTs for telecommunication has not yet been comprehensively studied, particularly in the aspects of fine-grained creation, real-time adaptation, resource-efficient deployment, and security protection. This article presents an in-depth overview of DNTs, exploring their concrete integration into networks and communication, covering the fundamental designs, the emergent applications, and critical challenges in multiple dimensions. We also include two detailed case studies to illustrate how DNTs can be applied in real-world scenarios such as wireless traffic forecasting and edge caching. Additionally, a forward-looking vision of the research opportunities in tackling the challenges of DNTs is provided, aiming to fully maximize the benefits of DNTs in nextG networks. ...

October 2025 · Z. Zhang, Z. Peng, H. Yu, M. Chen, Y. Liu

On Transferring, Merging, and Splitting Task-Oriented Network Digital Twins

Download Paper arXiv Abstract The integration of digital twinning technologies is driving next-generation networks toward new capabilities, allowing operators to thoroughly understand network conditions, efficiently analyze valuable radio data, and innovate applications through user-friendly, immersive interfaces. Building on this foundation, network digital twins (NDTs) accurately depict the operational processes and attributes of network infrastructures, facilitating predictive management through real-time analysis and measurement. However, constructing precise NDTs poses challenges, such as integrating diverse data sources, mapping necessary attributes from physical networks, and maintaining scalability for various downstream tasks. Unlike previous works that focused on the creation and mapping of NDTs from scratch, we explore intra- and inter-operations among NDTs within a Unified Twin Transformation (UTT) framework, which uncovers a new computing paradigm for efficient transfer, merging, and splitting of NDTs to create task-oriented twins. By leveraging joint multi-modal and distributed mapping mechanisms, UTT optimizes resource utilization and reduces the cost of creating NDTs, while ensuring twin model consistency. A theoretical analysis of the distributed mapping problem is conducted to establish convergence bounds for this multi-modal gated aggregation process. Evaluations on real-world twin-assisted applications, such as trajectory reconstruction, human localization, and sensory data generation, demonstrate the feasibility and effectiveness of interoperability among NDTs for corresponding task development. ...

September 2025 · Z. Zhang, M. Fang, M. Chen, Y. Liu

Research Intern

Oak Ridge National Laboratory (ORNL) Duration: [Start Date] – [End Date] (Please update the dates above as needed.) Project: ExaDIGIT — Exascale Digital Twins for HPC Network Systems Focus Areas: Design and development of exascale-level network digital twin frameworks Physical-digital synchronization for high-performance computing fabrics Topology-aware network representation and performance modeling Integration with ORNL’s production HPC systems Recognition: ExaDIGIT project honored with the 2025 R&D 100 Award

June 2025 · Z. Zhang

Synergizing AI and Digital Twins for Next-Generation Network Optimization, Forecasting, and Security

Download Paper arXiv Abstract Digital network twins (DNTs) are virtual representations of physical networks, designed to enable real-time monitoring, simulation, and optimization of network performance. When integrated with machine learning (ML) techniques, particularly federated learning (FL) and reinforcement learning (RL), DNTs emerge as powerful solutions for managing the complexities of network operations. This article presents a comprehensive analysis of the synergy of DNTs, FL, and RL techniques, showcasing their collective potential to address critical challenges in 6G networks. We highlight key technical challenges that need to be addressed, such as ensuring network reliability, achieving joint data-scenario forecasting, and maintaining security in high-risk environments. Additionally, we propose several pipelines that integrate DNT and ML within coherent frameworks to enhance network optimization and security. Case studies demonstrate the practical applications of our proposed pipelines in edge caching and vehicular networks. In edge caching, the pipeline achieves over 80% cache hit rates while balancing base station loads. In autonomous vehicular system, it ensures a 100% no-collision rate, showcasing its reliability in safety-critical scenarios. By exploring these synergies, we offer insights into the future of intelligent and adaptive network systems that automate decision-making and problem-solving. ...

March 2025 · Z. Zhang, M. Fang, D. Chen, X. Yang, Y. Liu

Digital Network Twins for Advanced Networks

Digital Network Twins (DNTs) are virtual representations of physical networks and offer promising solutions for managing complex network environments, especially when combined with machine learning. This talk discusses how DNTs address pressing challenges in advanced networks such as 6G, covering federated learning for privacy-preserving distributed model training, reinforcement learning for autonomous real-time decision-making, and practical applications including edge caching and secure vehicle networks. Topics Covered Network digital twin architecture and synchronization Federated learning for decentralized model training in DNTs Reinforcement learning for closed-loop network control Security: defending against poisoning attacks in distributed twin systems Applications: edge caching optimization, secure vehicular networks

January 2025 · Z. Zhang

Securing Distributed Network Digital Twin Systems Against Model Poisoning Attacks

Download Paper arXiv Abstract In the era of 5G and beyond, the increasing complexity of wireless networks necessitates innovative frameworks for efficient management and deployment. Digital twins (DTs), embodying real-time monitoring, predictive configurations, and enhanced decision-making capabilities, stand out as a promising solution in this context. Within a time-series data-driven framework that effectively maps wireless networks into digital counterparts, encapsulated by integrated vertical and horizontal twinning phases, this study investigates the security challenges in distributed network DT systems, which potentially undermine the reliability of subsequent network applications such as wireless traffic forecasting. Specifically, we consider a minimal-knowledge scenario for all attackers, in that they do not have access to network data and other specialized knowledge, yet can interact with previous iterations of server-level models. In this context, we spotlight a novel fake traffic injection attack designed to compromise a distributed network DT system for wireless traffic prediction. In response, we then propose a defense mechanism, termed global-local inconsistency detection (GLID), to counteract various model poisoning threats. GLID strategically removes abnormal model parameters that deviate beyond a particular percentile range, thereby fortifying the security of network twinning process. Through extensive experiments on real-world wireless traffic datasets, our experimental evaluations show that both our attack and defense strategies significantly outperform existing baselines, highlighting the importance of security measures in the design and implementation of DTs for 5G and beyond network systems. ...

July 2024 · Z. Zhang, M. Fang, M. Chen, G. Li, X. Lin, Y. Liu

Mapping Wireless Networks into Digital Reality through Joint Vertical and Horizontal Learning

Download Paper arXiv Abstract In recent years, the complexity of 5G and beyond wireless networks has escalated, prompting a need for innovative frameworks to facilitate flexible management and efficient deployment. The concept of digital twins (DTs) has emerged as a solution to enable real-time monitoring, predictive configurations, and decision-making processes. While existing works primarily focus on leveraging DTs to optimize wireless networks, a detailed mapping methodology for creating virtual representations of network infrastructure and properties is still lacking. In this context, we introduce VH-Twin, a novel time-series data-driven framework that effectively maps wireless networks into digital reality. VH-Twin distinguishes itself through complementary vertical twinning (V-twinning) and horizontal twinning (H-twinning) stages, followed by a periodic clustering mechanism used to virtualize network regions based on their distinct geological and wireless characteristics. Specifically, V-twinning exploits distributed learning techniques to initialize a global twin model collaboratively from virtualized network clusters. H-twinning, on the other hand, is implemented with an asynchronous mapping scheme that dynamically updates twin models in response to network or environmental changes. Leveraging real-world wireless traffic data within a cellular wireless network, comprehensive experiments are conducted to verify that VH-Twin can effectively construct, deploy, and maintain network DTs. Parametric analysis also offers insights into how to strike a balance between twinning efficiency and model accuracy at scale. ...

June 2024 · Z. Zhang, M. Chen, Z. Yang, Y. Liu

Digital Twin-Assisted Data-Driven Optimization for Reliable Edge Caching in Wireless Networks

Download Paper arXiv Abstract Optimizing edge caching is crucial for the advancement of next-generation (nextG) wireless networks, ensuring high-speed and low-latency services for mobile users. Existing data-driven optimization approaches often lack awareness of the distribution of random data variables and focus solely on optimizing cache hit rates, neglecting potential reliability concerns, such as base station overload and unbalanced cache issues. This oversight can result in system crashes and degraded user experience. To bridge this gap, we introduce a novel digital twin-assisted optimization framework, called D-REC, which integrates reinforcement learning (RL) with diverse intervention modules to ensure reliable caching in nextG wireless networks. We first develop a joint vertical and horizontal twinning approach to efficiently create network digital twins, which are then employed by D-REC as RL optimizers and safeguards, providing ample datasets for training and predictive evaluation of our cache replacement policy. By incorporating reliability modules into a constrained Markov decision process, D-REC can adaptively adjust actions, rewards, and states to comply with advantageous constraints, minimizing the risk of network failures. Theoretical analysis demonstrates comparable convergence rates between D-REC and vanilla data-driven methods without compromising caching performance. Extensive experiments validate that D-REC outperforms conventional approaches in cache hit rate and load balancing while effectively enforcing predetermined reliability intervention modules. ...

May 2024 · Z. Zhang, Y. Liu, Z. Peng, M. Chen, D. Xu, S. Cui

Research Assistant

Department of Computer Science, NC State University Duration: Summer 2024 – Present Research Focus: Network digital twin construction, synchronization, and security for HPC and wireless systems Federated learning robustness against poisoning and Byzantine attacks Reinforcement learning for closed-loop network control Collaboration with Oak Ridge National Laboratory (ExaDIGIT project, 2025 R&D 100 Award)

May 2024 · Z. Zhang