A user-centered approach to network quality of service and charging
The number of network users is expected to triple between 1998 and 2002 (Cullinane, 1998). While a vision of the future Internet offers the potential to break traditional barriers in communications and commerce, the current level of service does not satisfy the requirements of many users (Network Reliability Steering Committee, 1998, Cullinane, 1998). This thesis is concerned with users' perceptions of Quality of Service (QoS), and their attitudes to charging mechanisms applied to wide-area networks. Whilst the majority of research in this area has been conducted from a technical point of view, studies addressing issues of QoS and charging from a users' perspective are limited. The aim of this research was to investigate the latter issue to provide a more complete and integrated perspective on QoS and charging in the user-network system. The thesis first addresses previous work that looks at QoS and charging, establishing a justification for the new research. This part of the thesis concludes that, whilst part of our understanding of QoS requirements can be explained by technical and economic paradigms, additional research is required to examine the perceptions and concomitant behaviour of users. The methodology employed is outlined in relation to obtaining this objective. The second part of the thesis details work undertaken. This work has made the following main contributions: *Developed a set of conceptual models that describe users' perceptions of network QoS. *Shown that these models can be used to predict users' behaviour in different contexts by capturing subjective evaluations of QoS. * Shown how a combination of established and new methods can be successfully applied in capturing and assessing users' perceptions of QoS. *Shown how the new data relates to technical and econometric research. *Provided concrete examples of how the new research can inform network systems design. The work documented in this thesis has implications for user-centred, technical and econometric research. This thesis therefore contributes, not only to the field of HCI to which it is most closely related, but provides guidelines that can be used by econometricians and network designers. The research from all three of these perspectives is concerned with the efficient function of network resource allocation systems. The work documented in this thesis has suggested how it is possible to integrate these perspectives to provide valued levels of QoS to users.