On Network Performance Indicators for Network Promoter Score Estimation

Estimation of user perceived quality of offered services, from massive number of Key Performance Indicator (KPI)'s that are measured in diverse components, has been a necessity for mobile network operators. The goal is first to have a good estimator for poor Quality of Experience (QoE), which can potentially be achieved with machine learning, and then pinpoint the features that are contributing to the poor performance. There is often a tradeoff between accuracy and interpretability of models. In this paper, we address this tradeoff by first developing a robust but complex teacher machine learning model to map the subjective Net Promoter Score (NPS) values computed from the user quality feedback to the underlying subset of KPI metrics. Next, we develop a rather interpretable student model supervised by the pre-trained teacher model. Eventually the compact student decision tree model learns to mimic the behavior of the teacher model with an at least 10 % improved accuracy in testset as compared to conventional way of directly training using the decision tree model. In the last step, we extract the rules and important influential features of the distilled student model.