Smart Information Exchange for Unsupervised Federated Learning via Reinforcement Learning
Seohyun Lee, Anindya Bijoy Das, Satyavrat Wagle, Christopher G. Brinton
TL;DR
The paper addresses the challenge of non-i.i.d. data in unsupervised federated learning by introducing a reinforcement-learning-based method to discover an optimal device-to-device data exchange graph. It combines PCA for feature preservation, K-means++ for measuring cross-device dissimilarity, and autoencoders for unsupervised learning, enabling selective data transfers that improve convergence speed and robustness to stragglers. The authors propose a decentralized RL framework where each device learns which neighbor to connect to, guided by a reward that balances data diversity and communication reliability, and they validate the approach on FashionMNIST and CIFAR-10 across multiple FL schemes (FedAvg, FedSGD, FedProx). The results demonstrate faster reconstruction loss convergence, more discriminative latent embeddings, and greater resilience to transmission failures and stragglers, suggesting practical applicability as a plug-and-play enhancement for unsupervised FL with D2D exchanges.
Abstract
One of the main challenges of decentralized machine learning paradigms such as Federated Learning (FL) is the presence of local non-i.i.d. datasets. Device-to-device transfers (D2D) between distributed devices has been shown to be an effective tool for dealing with this problem and robust to stragglers. In an unsupervised case, however, it is not obvious how data exchanges should take place due to the absence of labels. In this paper, we propose an approach to create an optimal graph for data transfer using Reinforcement Learning. The goal is to form links that will provide the most benefit considering the environment's constraints and improve convergence speed in an unsupervised FL environment. Numerical analysis shows the advantages in terms of convergence speed and straggler resilience of the proposed method to different available FL schemes and benchmark datasets.
