User satisfaction classification for Minimization of Drive Tests QoS verification

In wireless mobile networks quality of user experience changes dynamically and depends on large variety of factors. Because of that mobile operators are willing to timely and effectively evaluate provided Quality of Service (QoS) in their networks. Nowadays the main tool for monitoring network state and performance is drive testing. To replace this expensive and mostly manual procedure, concept of Minimization of Drive Tests (MDT) is being developed in 3GPP LTE standardization. One area where MDT is applied is QoS verification, where user satisfaction is evaluated on the basis of periodic reports which contain values of different Key Performance Indicators (KPIs). By analyzing these KPIs one could find users which are unsatisfied with the experienced QoS and optimize configuration parameters in the areas of the network where concentration of unsatisfied users is high. In this paper we introduce a data mining framework which allows to distinguish between satisfied and unsatisfied users in LTE mobile network on the basis of limited number of KPIs. In addition, we take into use a KPI ranking system which gives an ability to significantly reduce the number of analyzed variables without compromising the resulting accuracy.