Abstract
Federated learning has emerged recently as a promising solution for distributing machine learning tasks through modern networks of mobile devices. Recent studies have obtained lower bounds on the expected decrease in model loss that is achieved through each round of federated learning. However, convergence generally requires a large number of communication rounds, which induces delay in model training and is costly in terms of network resources. In this paper, we propose a fast-convergent federated learning algorithm, called $\mathsf {FOLB}$ , which performs intelligent sampling of devices in each round of model training to optimize the expected convergence speed. We first theoretically characterize a lower bound on improvement that can be obtained in each round if devices are selected according to the expected improvement their local models will provide to the current global model. Then, we show that $\mathsf {FOLB}$ obtains this bound through uniform sampling by weighting device updates according to their gradient information. $\mathsf {FOLB}$ is able to handle both communication and computation heterogeneity of devices by adapting the aggregations according to estimates of device's capabilities of contributing to the updates. We evaluate $\mathsf {FOLB}$ in comparison with existing federated learning algorithms and experimentally show its improvement in trained model accuracy, convergence speed, and/or model stability across various machine learning tasks and datasets.
Original language | English (US) |
---|---|
Article number | 9252927 |
Pages (from-to) | 201-218 |
Number of pages | 18 |
Journal | IEEE Journal on Selected Areas in Communications |
Volume | 39 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2021 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications
- Electrical and Electronic Engineering
Keywords
- Federated learning
- distributed optimization
- fast convergence rate