Definition of QoE Fairness in Shared Systems

User-centric service and application management focuses on the quality of experience (QoE) as perceived by the end user. Thereby, the goal is to maximize QoE while ensuring fairness among users, e.g., for resource allocation and scheduling in shared systems. Although the literature suggests to consider consequently QoE fairness, there is currently no accepted definition of QoE fairness. The contribution of this letter is the definition of a generic <italic>QoE fairness index</italic> <inline-formula> <tex-math notation="LaTeX">$F$ </tex-math></inline-formula>, which has desirable key properties as well as the rationale behind it. By using examples and a measurement study involving multiple users downloading web content over a bottleneck link, we differentiate the proposed index from QoS fairness and the widely used Jain’s fairness index. Based on results, we argue that neither QoS fairness nor Jain’s fairness index meet all of the desirable QoE-relevant Properties, which are met by <inline-formula> <tex-math notation="LaTeX">$F$ </tex-math></inline-formula>. Consequently, the proposed index <inline-formula> <tex-math notation="LaTeX">$F$ </tex-math></inline-formula> may be used to compare QoE fairness across systems and applications, thus serving as a benchmark for QoE management mechanisms and system optimization.