Patrick Zwickl

The QoE alchemy: Turning quality into money. Experiences with a refined methodology for the evaluation of willingness-to-pay for service quality

Studying the connection between QoE and QoS and its implications for network and content providers has yielded a couple of well-established experimental approaches. However, research in this field has mainly neglected economical aspects of user trials. This paper describes and evaluates an extended experimental setup to investigate willingness-to-pay for enhanced video quality inferred from network quality parameters. The results confirm that our realistic setup provides valid results indicating the suitability for upcoming studies bringing economical aspects and QoE together.

The role of cognitive dissonance for QoE evaluation of multimedia services

In contrast to traditional QoS-based charging, charges for QoE (Quality of Experience) play a double role both as part of the evaluation context and as counterpart of the users willingness-to-pay for service quality. To further investigate this link between pricing and QoE, we combine some unexpected results from empirical quality perception experiments with the socio-psychological theory of cognitive dissonance. With this approach, we are able to explain the influence of active user decisions on QoE. Moreover, economical implications, further research opportunities and practical advices for quality testing are presented.

The trouble with choice: An empirical study to investigate the influence of charging strategies and content selection on QoE

Despite the fact that novel QoE based charging mechanism are vitally needed, the complex interrelation of payment and quality perception has been examined only marginally so far. In this paper we want to describe a comprehensive experiment which investigates the intricate interplay of content selection, quality decisions & evaluation and payment strategies in the context of a video on demand scenario. Beside depicting methodological challenges and providing recommendations for further empirical work, we also compare current findings with our previous work to reveal new sights and research attempts.

A fixed-point model for QoE-based charging

Within the current paradigm change from Quality-of-Service (QoS) towards Quality-of-Experience (QoE), the question of how to charge for QoE is widely neglected in the research community despite of its obvious importance. In this paper, we present and analyze a fixed point model which specifically reflects the double role of prices, i.e. as regulating factor for demand size and at the same time as part of the QoE-based user context. The model is validated through comprehensive user trial results which allow interesting insights into the temporal behavior of end users who are confronted with a fine-grained scale of choices on video quality and corresponding tariffs.

From Service Level Agreements (SLA) to Experience Level Agreements (ELA): The challenges of selling QoE to the user

In contrast to the rather network-centric notion of Quality of Service (QoS), the concept of Quality of Experience (QoE) has a strongly user-centric perspective on service quality in communication networks as well as online services. However, related research on QoE so far has largely neglected the question of how to operationalize quality differentiation and to provide corresponding solutions tailored to the end users. In this paper, we argue that the introduction of Experience Level Agreements (ELA) as QoE-enabled counterpiece to traditional QoS-based Service Level Agreements (SLA) would provide a key step towards being able to sell service quality to the user. Hence, we investigate various ideas to exploit QoE awareness for improving SLAs (ranging from internal aspects like SLOs by service providers to completely novel definitions of ELAs which are able to characterize QoE explicitly), and discuss important problems and challenges of the proposed transition as well.

Towards the cross-domain interoperability of IoT platforms

The Internet of Things is evolving around a plethora of vertical platforms, each specifically suited to a given scenario and often adopting proprietary communications, device and resource control protocols. The emerging need for cross-domain IoT applications and services highlights the necessity of interoperability across IoT platforms for a unified and secure sharing of and access to sensing/actuating resources. This position paper describes the current state of the IoT landscape, the opportunities that appear towards its sustainable evolution as well as the challenges that need to be addressed. In this context, the vision and objectives of the H2020 symbIoTe project are also presented; symbIoTe aims at the interoperability of IoT platforms by offering a flexible interoperability framework that will allow i) vertical IoT platforms to cooperate, ii) collaborative IoT platforms to form IoT-platform federations for exchange of resources and iii) independent developers to create innovative and cross-domain applications.

On the quantification of value networks: a dependency model for interconnection scenarios

Caused by the non-linearity of some industries such as networking interconnection, the deep understanding of Value Networks has grown in importance. While related works such as Value Network Analysis have been subject to the available qualitative mechanisms, this papers aims at quantifying actor dependencies within Value Networks. To this end, a series of dependency indicators are proposed based on wellestablished economic principles like Porters Five Forces on firms. This approach is validated through a case study analysing the replaceability of Transit Network Service Providers. Finally, an outlook on bargaining strategies based on these dependency indicators is given.

Market entrance, user interaction and willingness-to-pay: Exploring fundamentals of QoE-based charging for VoD services

Strongly rising interest in Quality of Experience (QoE) research together with the current economical struggle of Network Service Providers (NSPs) are about to lead towards monetization of QoE overtaking outright quality optimization in importance. While there is still a significant lack of quantitative studies for backing QoE-based charging recommendations, the present work presents results and conclusions from a recent empirical user study explicitly measuring the maximum willingness-to-pay of end users for High Definition (HD) Video on Demand (VoD) services. Beyond the observation of unexpectedly high expenditures by test subjects, we focus on phenomena with respect to market entrance pricing strategies, which may be explained by anchoring effects well-known in psychology. Thus, the present work provides valuable clues on how to approach VoD markets in an optimal and economically efficient way.

Network quality differentiation: Regional effects, market entrance, and empirical testability

While for offline business models it does not seem necessary to reiterate the close relationship between quality and price, for Internet services the quality-based, i.e., Quality of Experience (QoE), and customer-centric pricing is non-trivial. As insufficient data exists today to successfully commercialise QoE, this paper collects the integral empirical Willingness-To-Pay (WTP) data for the case of online video services. This work reproduces and extends a previous study in two dedicated campaigns in Austria and Finland. The campaigns study QoE and WTP related to Dynamic Adaptive Streaming over HTTP (DASH). They also confirm or disprove previous studies, openly share the data, and provide empirical background information on the purchasing behavior of customers. Due to the testing at two locations, we can further first time study whether cultural or regional differences affect the purchasing behaviors of such services. Additionally this paper gives insights and updated methodological guidance on conducting future WTP studies.

On the approximation of ISP and user utilities from quality of experience

While the network quality research has been oscillating between user- and technology-driven viewpoints, the evolution of a utility-centric perspective is still a good way off. Today, not only insufficient data exists on network quality market figures, but also on the users usage appreciation across service types and test ranges. Filling those research gaps, the present work presents a novel model, mainly constructed around existing empirical Quality of Experience (QoE) materials, which approximates both ISP and user utilities. A focus is set on the case of controlled quality and service degradations that intelligently adapt services upon resource shortages. In a case study, this model is applied to the case of Video on Demand services.