Communication overhead is one of the major challenges in Federated Learning(FL). A few classical schemes assume the server can extract the auxiliary information about training data of the participants from the local models to construct a central dummy dataset. The server uses the dummy dataset to finetune aggregated global model to achieve the target test accuracy in fewer communication rounds. In this paper, we summarize the above solutions into a data-based communication-efficient FL framework. The key of the proposed framework is to design an efficient extraction module(EM) which ensures the dummy dataset has a positive effect on finetuning aggregated global model. Different from the existing methods that use generator to design EM, our proposed method, FedINIBoost borrows the idea of gradient match to construct EM. Specifically, FedINIBoost builds a proxy dataset of the real dataset in two steps for each participant at each communication round. Then the server aggregates all the proxy datasets to form a central dummy dataset, which is used to finetune aggregated global model. Extensive experiments verify the superiority of our method compared with the existing classical method, FedAVG, FedProx, Moon and FedFTG. Moreover, FedINIBoost plays a significant role in finetuning the performance of aggregated global model at the initial stage of FL.

翻译：通信开销是联邦学习（FL）中的主要挑战之一。一些经典方案假设服务器能够从局部模型中提取参与方训练数据的辅助信息，从而构建中央虚拟数据集。服务器利用该虚拟数据集对聚合后的全局模型进行微调，以在更少的通信轮次中达到目标测试精度。本文将上述方案归纳为一种基于数据的通信高效联邦学习框架。该框架的关键在于设计高效提取模块（EM），确保虚拟数据集对聚合全局模型的微调产生积极作用。与现有使用生成器设计EM的方法不同，本文提出的FedINIBoost方法借鉴了梯度匹配的思想来构建EM。具体而言，FedINIBoost在每个通信轮次为每个参与方分两步构建真实数据的代理数据集，随后服务器聚合所有代理数据集形成中央虚拟数据集，用于微调聚合全局模型。大量实验验证了该方法相较于现有经典方法（FedAVG、FedProx、Moon和FedFTG）的优越性。此外，FedINIBoost在联邦学习初始阶段对聚合全局模型的微调性能具有显著提升作用。