Journal of Vocational, Informatics and Computer Education
Vol 4, No 2 (2026): June 2026

Reinforcement Learning-Based Adaptive Threshold Optimization for Federated Sequence-to-Sequence Anomaly Detection in IoT Network Traffic

Rahmad Hidayat Hadi Subroto (Universitas Indonesia, Indonesia)
Kalamullah Ramli (Universitas Indonesia, Indonesia)



Article Info

Publish Date
28 Jun 2026

Abstract

Purpose – This study evaluates reinforcement learning (RL)-based adaptive threshold optimization for binary Internet of Things (IoT) network anomaly detection in a federated sequence-to-sequence (Seq2Seq) reconstruction model. Reconstruction-based detectors require a threshold to convert anomaly scores into benign-or-attack decisions, and a fixed threshold may not provide the most suitable operating point in federated non-IID settings.Methods – An LSTM Seq2Seq autoencoder was implemented using a controlled CICIoT2023 subset with 182,829 records and 39 numerical traffic features. Three scenarios were compared: centralized Seq2Seq with static threshold, federated Seq2Seq with static threshold, and federated Seq2Seq with RL-based adaptive threshold. Federated learning used five simulated clients, Dirichlet non-IID partitioning with α = 0.5, three local epochs, ten communication rounds, and weighted FedAvg aggregation. The RL component was implemented as an offline validation-based threshold optimizer and selected a single final threshold after federated training. Findings – Compared with federated static thresholding, the RL-based adaptive threshold improved accuracy from 92.97% to 95.71%, recall from 91.60% to 98.21%, and F1-score from 94.98% to 97.08%. FNR decreased from 8.40% to 1.79%, while FPR increased from 3.40% to 10.95%.Research implications – Threshold optimization should be treated as a decision-layer component in federated reconstruction-based IDS. The proposed pipeline may also support vocational informatics and cybersecurity education as a case study on federated learning, anomaly detection, and threshold-based IDS trade-offs.Originality – This study positions RL-based threshold adaptation as a decision-layer component in federated reconstruction-based IoT anomaly detection.

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Journal Info

Abbrev

VOICE

Publisher

Subject

Computer Science & IT Education

Description

1. Informatics and Computing Research addressing the design, development, implementation, and evaluation of computing technologies relevant to educational, professional, and digital learning environments, including but not limited to: Artificial Intelligence and Machine Learning Deep Learning and ...