Stimulus-centric versus perception-centric relations in quality of experience assessment

Researchers as well as network providers are increasingly interested in how a network user´s experience changes in relation to different quality of service (QoS) parameters, with many attempts being made to identify the general relationship between quality of experience (QoE) and QoS. Several relations in different function forms have been proposed. There are instances when this variety of proposed functions potentially results in one problem having completely dissimilar solutions at the same time. For example, the general correlation between QoE and QoS can be explained with two different function forms (i.e. logarithmic and also exponential) at the same time. The question then is which function form is the one that can better explain this relationship. To answer this question, it could be of help to compare the various existing relations, particularly by comparing two different definition types that lead to QoE-QoS dependency. First, the Weber-Fechner Law was reviewed. It is a psychophysics law showing a logarithmic function that can be used to explain the interdependency between QoE and QoS. Next, the IQX hypothesis was investigated, and it introduces an exponential relation between QoE and QoS. These two functions are grouped into stimulus-centric and perception-centric relations. The relation adopted from psychophysics goes into the stimulus-centric group, while the IQX-based relation falls into the perception-centric group. Later, a detailed explanation of the two groups is discussed, after which an experimentally supported comparison between them explores how they clarify QoE changes in relation to QoS parameter changes. Therefore, an appropriately successful relation can be selected from the theoretical comparison results as well as the experiment outcomes.