End-to-End Evaluation of Federated Learning and Split Learning for Internet of Things

TL;DR

This paper compares federated learning and split neural networks in real-world IoT environments, evaluating their performance, overheads, and limitations across various datasets and device setups.

Contribution

It provides the first comprehensive real-world comparison of FL and SplitNN in IoT, highlighting their performance differences and implementation challenges.

Findings

SplitNN outperforms FL on imbalanced data

FL has lower communication overhead than SplitNN

SplitNN has limitations revealed for future research

Abstract

This work is the first attempt to evaluate and compare felderated learning (FL) and split neural networks (SplitNN) in real-world IoT settings in terms of learning performance and device implementation overhead. We consider a variety of datasets, different model architectures, multiple clients, and various performance metrics. For learning performance, which is specified by the model accuracy and convergence speed metrics, we empirically evaluate both FL and SplitNN under different types of data distributions such as imbalanced and non-independent and identically distributed (non-IID) data. We show that the learning performance of SplitNN is better than FL under an imbalanced data distribution, but worse than FL under an extreme non-IID data distribution. For implementation overhead, we end-to-end mount both FL and SplitNN on Raspberry Pis, and comprehensively evaluate overheads including training time, communication overhead under the real LAN setting, power consumption and memory usage. Our key observations are that under IoT scenario where the communication traffic is the main concern, the FL appears to perform better over SplitNN because FL has the significantly lower communication overhead compared with SplitNN, which empirically corroborate previous statistical analysis. In addition, we reveal several unrecognized limitations about SplitNN, forming the basis for future research.