Version age-based client scheduling policy for federated learning
This addresses communication bottlenecks and stability issues in federated learning for edge device applications, representing an incremental improvement over existing scheduling strategies.
The paper tackles the problem of stragglers and outdated updates in federated learning by introducing a Version Age of Information (VAoI) metric that combines timeliness and content staleness into a client scheduling policy, resulting in minimized average VAoI and enhanced system stability.
Federated Learning (FL) has emerged as a privacy-preserving machine learning paradigm facilitating collaborative training across multiple clients without sharing local data. Despite advancements in edge device capabilities, communication bottlenecks present challenges in aggregating a large number of clients; only a portion of the clients can update their parameters upon each global aggregation. This phenomenon introduces the critical challenge of stragglers in FL and the profound impact of client scheduling policies on global model convergence and stability. Existing scheduling strategies address staleness but predominantly focus on either timeliness or content. Motivated by this, we introduce the novel concept of Version Age of Information (VAoI) to FL. Unlike traditional Age of Information metrics, VAoI considers both timeliness and content staleness. Each client's version age is updated discretely, indicating the freshness of information. VAoI is incorporated into the client scheduling policy to minimize the average VAoI, mitigating the impact of outdated local updates and enhancing the stability of FL systems.