Study on Transmission Optimization for Hierarchical Federated Learning

Abstract

Compared with traditional machine learning,federated learning effectively solves the problems of user data privacy and security protection,but a large number of model exchanges between massive nodes and cloud servers will produce high communication costs.Therefore,cloud-edge-side layered federated learning has received more and more attention.In hierarchical federated learning,D2D and opportunity communication can be used for model cooperation training among mobile nodes.Edge server performs local model aggregation,while cloud server performs global model aggregation.In order to improve the convergence rate of the model,the network transmission optimization technique for hierarchical federated learning is studied.This paper introduces the concept and algorithm principle of hierarchical federated learning,summarizes the key challenges that cause network communication overhead,summarizes and analyzes six network transmission optimization methods,such as selecting appropriate nodes,enhancing local computing,reducing the upload number of local model updates,compressing model updates decentralized training and parameter aggregation oriented transimission.Finally,the future research direction is summarized and discussed.

Keywords

• hierarchical federated learning|transmission optimization|communication overhead|node selection|model compression