We envision a mobile edge computing (MEC) framework for machine learning (ML) technologies, which leverages distributed client data and computation resources for training high-performance ML models while preserving a client privacy. Toward this future goal, this work aims to extend Federated Learning (FL), which enables privacy-preserving training of models, to work with heterogeneous clients in a practical cellular network. The FL protocol iteratively asks random clients to download a trainable model from a server, update it with own data, and upload the updated model to the server, while asking the server to aggregate multiple client updates to further improve the model. While clients in this protocol are free from disclosing own private data, the overall training process can become inefficient when some clients are with limited computational resources (i.e., requiring longer update time) or under poor wireless channel conditions (longer upload time). Our new FL protocol, which we refer to as FedCS, mitigates this problem and performs FL efficiently while actively managing clients based on their resource conditions. Specifically, FedCS solves a client selection problem with resource constraints, which selects the maximum possible number of clients who can complete the FL's download, update, and upload steps within a certain deadline. This selection strategy results in the server aggregating as many client updates as possible and accelerating performance improvement in ML models (e.g., classification accuracy.) We conducted an experimental evaluation using publicly-available large-scale image datasets to train deep neural networks on MEC environment simulations. The experimental results show that FedCS is able to complete its training process in a significantly shorter time compared to the original FL protocol.

本篇论文中，我们介绍了一种基于移动边缘计算，利用分布式客户端数据和计算资源进行高性能机器学习模型训练的框架，该框架扩展了联邦学习的分布式学习框架，以实现与实际基于蜂窝网络的异构客户端的协作；我们的新FL协议（FedCS）通过解决具有资源限制的客户端选择问题来提高训练效率，在公开可用的大规模图像数据集上进行实验，实验结果表明，与原始FL协议相比，FedCS能够在显著缩短的时间内完成训练。

移动边缘异构资源联邦学习的客户端选择