rable parameters. Such QoS parameters are defined for QoS measurements on a national basis (or globally). Examples of technical KPIs include voice call success rate, call drop rate, bitrates in downlink and uplink, messages delivery time, etc. Non-technical KPIs are focused on the customer's subjective opinion and typically include parameters such as billing accuracy, fault, customer care response time, or satisfaction from the response, etc. Step 4. Monitoring of defined KPIs. This includes measurement of technical KPIs via network auditing, drive tests in mobile networks, etc., as well as subjective customer surveys of non-technical KPIs via questionnaires or customer responses. Different measurement methods (to monitor KPIs) can be used in different countries. Such KPI monitoring can be performed by NRAs, telecom operators, independent organi- zations, and also by customers (e.g. via installed software or hardware probes in their home networks or on their devices). The purpose of monitoring defined KPIs (used to define the required QoS in a given country) is to detect degradation of QoS when it appears and then to apply appropriate measures. For example, QoS enforcement can be performed through a regulatory notice (e.g. publishing KPI monitoring results on a public website, through press releases, via directives) to allow customers to make informed choices. But when the applied QoS enforcement measures are not enough to improve degraded or low level QoS, more dras- tic QoS enforcement measures should be taken, such as financial penalties (e.g. applied to non-conforming operators or service providers) or opening a dispute. 9 QoS Regulatory Framework In general, there are four main regulator approaches to deal with QoS matters [2]: Obtaining appropriate information on the level of QoS and identifying problem areas. This approach is needed to obtain information (from QoS measurements, customer surveys, etc.) which will be needed for a decision on imposing certain QoS measures. Undertaking a constructive dialog wi