Edge-cloud Collaborative Learning with Federated and Centralized Features

Federated learning (FL) is a popular way of edge computing that does not compromise user's privacy. Current FL paradigms assume data only resides on the edge, while cloud servers only perform model averaging. However, in real-life situations such as recommender systems, the cloud server usually has abundant features and computation resources. Specifically, the cloud stores historical and interactive features, and the edge stores privacy-sensitive and real-time features. In this paper, our proposed Edge-Cloud Collaborative Knowledge Transfer Framework (ECCT) jointly utilizes the edge-side features and the cloud-side features, enabling bi-directional knowledge transfer between the two by sharing feature embeddings and prediction logits. ECCT consolidates various benefits, including enhancing personalization, enabling model heterogeneity, tolerating training asynchronization, and relieving communication burdens. Extensive experiments on public and industrial datasets demonstrate the effectiveness of ECCT.