User-centric Quality of Service Management in UMTS

The introduction of UMTS has fuelled the demand for mobile services having a range of QoS constraints. The mobile operator has the means to set network QoS levels but its final aim is to meet user satisfaction while minimizing resource consumption. In this article we study the relationship between UMTS network QoS levels and the user perception of QoS. We report our findings based on a subjective study involving over 100 users for a 2-year period. Our statistical analysis correlates individual QoS parameters with the user opinion on service quality. We determined that the optimum range of bandwidth for web browsing over UMTS is comprised between 64 and 128kbps. We have also found the conditions under which graceful degradation of QoS is not easily perceived by the UMTS user, which suggests various new ways of managing over-the-air resources. Our methodology can also be applied to conduct similar studies for any other service.