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

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

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

Poisoning Attacks on Federated Learning-based Wireless Traffic Prediction

Download Paper arXiv Abstract Federated Learning (FL) offers a distributed framework to train a global control model across multiple base stations without compromising the privacy of their local network data. This makes it ideal for applications like wireless traffic prediction (WTP), which plays a crucial role in optimizing network resources, enabling proactive traffic flow management, and enhancing the reliability of downstream communication-aided applications, such as IoT devices, autonomous vehicles, and industrial automation systems. Despite its promise, the security aspects of FL-based distributed wireless systems, particularly in regression-based WTP problems, remain inadequately investigated. In this paper, we introduce a novel fake traffic injection (FTI) attack, designed to undermine the FL-based WTP system by injecting fabricated traffic distributions with minimal knowledge. We further propose a defense mechanism, termed global-local inconsistency detection (GLID), which strategically removes abnormal model parameters that deviate beyond a specific percentile range estimated through statistical methods in each dimension. Extensive experimental evaluations, performed on real-world wireless traffic datasets, demonstrate that both our attack and defense strategies significantly outperform existing baselines. ...

June 2024 · Z. Zhang, M. Fang, J. Huang, 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

Teaching Assistant

Department of Electrical and Computer Engineering, The Ohio State University Duration: Fall 2021 – Spring 2023 Courses: ECE-3561: Advanced Digital Design Supported lab sessions, graded projects, assisted with FPGA and hardware description language instruction ECE-5101: Wireless Networks Held office hours, assisted with problem sets on communication theory and network protocols

August 2021 · Z. Zhang