Recent studies in federated learning (FL) have focused on static datasets, but in real-world scenarios, data often arrives in streams with shifting distributions, leading to concept drift and performance degradation.
A new paper presents an information-theoretic analysis of FL performance under concept drift, introducing the concept of Stationary Generalization Error to evaluate a model's ability to capture characteristics of future unseen data.
The paper models concept drift as a Markov chain and proposes an algorithm that incorporates KL divergence and mutual information to mitigate performance degradation caused by drift patterns like periodic, gradual, and random changes in data distribution.
Experimental results using a Raspberry Pi4 FL testbed validate the proposed algorithm, showing improved performance over existing approaches in adapting to concept drift, highlighting the importance of considering shifting data distributions in FL.