Evaluating the Impact of Mobility on Differentially Private Federated Learning

This paper investigates differential privacy in federated learning. This topic has been actively examined in conventional network environments, but few studies have investigated it in the Internet of Vehicles, especially considering various mobility patterns. In particular, this work aims to measure and enumerate the trade-off between accuracy of performance and the level of data protection and evaluate how mobility patterns affect it. To this end, this paper proposes a method considering three factors: learning models, vehicle mobility, and a privacy algorithm. By taking into account mobility patterns, local differential privacy is enhanced with an adaptive clipping method and applied to a mobility-based federated learning model. Experiments run the model on vehicular networks with two different mobility scenarios representing a non-accident traffic situation and traffic events, respectively. Results show that our privacy-enhanced federated learning models degrade accuracy performance by 2.96–3.26% on average, which is compared to the performance drop (42.97% on average) in conventional federated learning models.