  In the paper by Wei et al. ("Federated Learning with Differential Privacy:
Algorithms and Performance Analysis"), the convergence performance of the
proposed differential privacy algorithm in federated learning (FL), known as
Noising before Model Aggregation FL (NbAFL), was studied. However, the
presented convergence upper bound of NbAFL (Theorem 2) is incorrect. This
comment aims to present the correct form of the convergence upper bound for
NbAFL.
