This Recommendation specifies a functional architecture of machine learning based quality of service (QoS) assurance for the international mobile telecommunications 2020 (IMT-2020) network. It first provides an overview of architectural framework for machine learning in IMT-2020 [ITU-T Y.3172]. It then describes the functional architecture of machine learning based QoS assurance for the IMT-2020 network including the reference points. It finally specifies the procedures of machine learning based QoS assurance for the IMT-2020 network.