One-Shot Federated Learning with Classifier-Free Diffusion Models
This addresses communication costs in federated learning for distributed systems, offering an incremental improvement over existing methods.
The paper tackles the communication overhead in one-shot federated learning by proposing OSCAR, which uses classifier-free diffusion models to generate server-side data without auxiliary classifiers, achieving state-of-the-art performance on four datasets and reducing communication load by at least 99%.
Federated learning (FL) enables collaborative learning without data centralization but introduces significant communication costs due to multiple communication rounds between clients and the server. One-shot federated learning (OSFL) addresses this by forming a global model with a single communication round, often relying on the server's model distillation or auxiliary dataset generation - often through pre-trained diffusion models (DMs). Existing DM-assisted OSFL methods, however, typically employ classifier-guided DMs, which require training auxiliary classifier models at each client, introducing additional computation overhead. This work introduces OSCAR (One-Shot Federated Learning with Classifier-Free Diffusion Models), a novel OSFL approach that eliminates the need for auxiliary models. OSCAR uses foundation models to devise category-specific data representations at each client, seamlessly integrated into a classifier-free diffusion model pipeline for server-side data generation. OSCAR is a simple yet cost-effective OSFL approach that outperforms the state-of-the-art on four benchmarking datasets while reducing the communication load by at least 99%.