 of the network coverage. However, without QoS performance management, the perceived QoE is close to useless in the context of optimisation, since no correlation can be studied between the QoS and QoE. The logic connection among those concepts can be expressed in the following process flow: The ultimate goal is to ensure a satisfactory QoE, measured through so-called QoE KPIs. The operator tool to ensure that goal is the mobile network. The closest perception of service performance in the mobile network is provided by the performance of the QoS, which can be quantified as QoS KPIs. The operator needs a simple mechanism to collect service based QoS KPIs. Once those service based QoS KPIs are collected from network elements and/or interfaces, they can be analysed. The closest perception of service performance in the terminal side is the QoE, which can be quantified as QoE KPIs. The operator needs a simple mechanism to collect service based QoE KPIs. Currently the possibilities are field test campaigns and field probes. Once those service based QoE KPIs are collected from field probes or end-to-end testing campaigns, they can be analysed accordingly. Eventually, from both parallel analyses, correlations can be found and improvement actions can be decided within the reach of current possibilities. The main difficulties are two: to provide a simplified mechanism to collect those service based KPIs; to build meaningful correlations between service based QoS KPIs and their corresponding service based QoE KPIs. The first difficulty can only be partially solved through a thorough study and definition of the meaningful QoS attributes that are relevant from an end user perspective and deep alignment of the OSS concept with Quality of Service the network nodes. This will provide a simple context of a few meaningful KPIs that can be uniquely associated to a given service or application. Some vendors in the industry are already exploring this area, with promising results. The second one is certainly uncharted territory, where 