Federated Learning Optimization: A Comparative Study of Data and Model Exchange Strategies in Dynamic Networks
Alka Luqman, Yeow Wei Liang Brandon, Anupam Chattopadhyay
TL;DR
This work tackles the problem of optimizing knowledge transfer in dynamic federated learning by systematically comparing data-exchange strategies (raw data and synthetic data) with model-update exchanges, including foundations-model-based updates, under non-IID data and ad-hoc network conditions. It introduces a Peer-to-Peer FL framework (PeerFL) and an adaptive hybrid transfer algorithm that balances compute and communication costs through an action-reward mechanism, where $Reward(Action) = E[AccuracyIncrease|Action]$ and costs are captured by $C^{comm}$. Experimental results on CIFAR-10 with non-IID partitions and on KITTI object detection demonstrate that data-sharing approaches can achieve faster convergence at the expense of higher bandwidth, while model-sharing provides stability with fewer rounds; synthetic data can match raw data performance in several skewed scenarios, and pre-trained foundational models show diminishing returns in some regimes. The findings underscore the value of adaptive, hybrid strategies for real-world dynamic networks and suggest privacy-conscious extensions such as differential privacy and secure multi-party computation to further strengthen robustness and applicability.
Abstract
The promise and proliferation of large-scale dynamic federated learning gives rise to a prominent open question - is it prudent to share data or model across nodes, if efficiency of transmission and fast knowledge transfer are the prime objectives. This work investigates exactly that. Specifically, we study the choices of exchanging raw data, synthetic data, or (partial) model updates among devices. The implications of these strategies in the context of foundational models are also examined in detail. Accordingly, we obtain key insights about optimal data and model exchange mechanisms considering various environments with different data distributions and dynamic device and network connections. Across various scenarios that we considered, time-limited knowledge transfer efficiency can differ by up to 9.08\%, thus highlighting the importance of this work.
