Quantifying the impact of network bandwidth fluctuations and outages on Web QoE

The systematic investigation of network bandwidth fluctuations and their impact on Quality of Experience (QoE) has recently gained center stage, not only in academia but also among network providers. This development is driven by the fact that in a real world usage scenario, volatile network performance (and thus varying QoE) actually is the norm, particularly in mobile contexts. However, we are still witnessing a lack of validated fluctuation models and applicable performance indicators to represent the QoE impact of network quality variations in provider-relevant network planning & management processes. In addition, fundamental phenomena like the impact of single bandwidth outage events on Web QoE (which occur e.g. during a handover between different base stations) have not been studied yet. In this paper we present the results of an empirical Web-QoE user study which a) lay the path towards the analysis of different bandwidth fluctuation models and b) provide insights into the impact of a single outage (i.e. zero network bandwidth) events on subjective quality perception. Furthermore, our experimental setup that exerts short & repetitive testing-conditions provides methodological guidance on how to perform subjective quality testing in the context of fluctuations and Web QoE.