Isabelle Stevens

E–deliberation 2.0 for smart cities: a critical assessment of two 'idea generation' cases

This paper elaborates on the importance of a user-driven approach in the design and development of innovative services and applications for smart cities. By reporting on two case studies situated in the city of Ghent (Belgium), that are part of larger projects, we illustrate how we have applied different user-centred innovation development methods and strategies in order to generate and evaluate innovative concepts and ideas for smart city applications. This paper discusses and compares the work conducted in these case studies by documenting for each case study (a) the policy context and strategy, (b) the problems addressed and the solutions achieved, and (c) the (e-)deliberation (2.0) approaches used. Furthermore, we assess the effectiveness and impact of both approaches and report on the results and the lessons learned.

Analysis of the quality of experience of a commercial voice-over-IP service

Voice-over-IP (VoIP) services, enabling users to make cheap phone calls using the Internet, are becoming increasingly popular, not only on desktop computers but also on mobile devices such as smartphones that are connected through mobile networks. Users’ perception of the level of quality plays a key role in making a VoIP service to succeed or to fail. This paper demonstrates the influence of technical parameters (such as the audio codec, type of data network, and handovers during the call), device characteristics (such as the platform, manufacturer, model, and operating system), and application aspects (such as the software version and configuration) on the subjective quality of a commercial VoIP service. The relative influence of all these parameters is determined and a decision tree combines these results in order to assess the subjective quality. Combining a large number of objective parameters in a decision tree to determine the user’s subjective evaluation of the quality of a VoIP call is a novel and complex procedure. The subjective quality, in turn, has an influence on the duration of the call, and as a result an influence on the usage behavior of the service. The users’ assessment of the service quality is not evaluated by merely taking a snapshot of the perceived quality at one moment in time but rather by analyzing the perceived quality over a longer period of time during service usage, which has not been done up to now. Analyzing the VoIP service using a regression analysis over a period of 120 days showed that the perceived quality decreases slightly when the user utilizes the service more often and gets more familiar with it.

Quality assessment and usage behavior of a mobile voice-over-IP service

Voice-over-IP (VoIP) services offer users a cheap alternative to the traditional mobile operators to make voice calls. Due to the increased capabilities and connectivity of mobile devices, these VoIP services are becoming increasingly popular on the mobile platform. Understanding the user’s usage behavior and quality assessment of the VoIP service plays a key role in optimizing the Quality of Experience (QoE) and making the service to succeed or to fail. By analyzing the usage and quality assessments of a commercial VoIP service, this paper identifies device characteristics, context parameters, and user aspects that influence the usage behavior and experience during VoIP calls. Whereas multimedia services are traditionally evaluated by monitoring usage and quality for a limited number of test subjects and during a limited evaluation period, this study analyzes the service usage and quality assessments of more than thousand users over a period of 120 days. This allows to analyze evolutions in the usage behavior and perceived quality over time, which has not been done up to now for a widely-used, mobile, multimedia service. The results show a significant evolution over time of the number of calls, the call duration, and the quality assessment. The time of the call, the used network, and handovers during the call showed to have a significant influence on the users’ quality assessments.