D-CAD: Decentralized Continual Anomaly Detection through Collaborative Knowledge Fusion in Wireless Sensor Networks

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Gajalakshmi P
Vijayakumar Kadumbadi
M. Ezhilvendan
M. Sadhasivam
Sevanthi P
K Vani Shree

Abstract

Wireless Sensor Networks (WSNs) are critical for real-time monitoring in industrial and environmental applications, where robust anomaly detection is essential for safety and efficiency. However, existing approaches face a trilemma: centralized methods create communication bottlenecks and single points of failure, isolated on-device learning cannot leverage collective knowledge, and static models degrade under real-world concept drifts. To overcome these limitations, we propose D-CAD, a novel framework for Decentralized Continual Anomaly Detection. D-CAD enables sensor nodes to collaboratively learn and adapt detection models over time using a lightweight, gossip-based knowledge fusion protocol, thereby eliminating the need for a central coordinator. Our method combines local lightweight autoencoders with a replay-based memory buffer to mitigate catastrophic forgetting and a dynamic weighting mechanism for effective peer-to-peer model fusion. Evaluated on the SWaT industrial dataset and a simulated non-IID WSN testbed, D-CAD achieved an average F1-score of 0.92, outperforming a centralized continual learner by 8% and isolated nodes by 23%. It maintains high accuracy while reducing the total network communication overhead by 65% compared with standard Federated Learning. Thus, D-CAD provides a scalable, robust, and communication-efficient paradigm for lifelong anomaly detection in distributed-sensing systems.

Article Details

How to Cite
[1]
G. . P, V. Kadumbadi, M. Ezhilvendan, M. Sadhasivam, S. P, and K. V. . Shree, “D-CAD: Decentralized Continual Anomaly Detection through Collaborative Knowledge Fusion in Wireless Sensor Networks”, ECTI-CIT Transactions, vol. 20, no. 3, pp. 411–424, May 2026.
Section
Research Article

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