Subjective assessment and instrumental prediction of mobile online gaming on the basis of perceptual dimensions
The assessment of the perceived quality of the user (Quality of Experience) of pure audio and video material differs in many ways from the quality of computer games. The later possess a variety of factors due to their interactive nature. Not only factors of complex and innovative game systems have an impact on the QoE, but also the players themselves. A quality judgment, that results by comparing the expected and perceived composition of an entity, depends highly on the preferences, expectations and abilities of the player.
In this still young area of research standard methods for determining the QoE are not directly applicable. This is apparent since in a task oriented human-computer interaction the goal should be achieved with minimal effort. However in a game the player exerts an effort in order to influence the outcome and thereby feels emotionally attached. Thus new concepts such as immersion and flow, a state of happiness while being in an equilibrium between competence and challenge, appear.
An analysis of the gaming market shows, that the proportion of mobile games has risen sharply in recent years. Mobile games are special in a sense that mobile devices such as smartphones or tablets were originally not designed for games and are therefore not optimally adapted to them. This also applies to the new concept of cloud gaming, where the entire game is executed on a server and only the video and audio material is transferred to the end user.
Aim of the project
The aim of this research project is to develop methods to assess the QoE of mobile games. In addition, based on a database containing subjective quality judgments, a model similar to the well known E-model should be constructed to predict the QoE. The following concrete steps are planned for this purpose:
- Set up and modification of a testbed for conducting experiments including a cloud gaming system for mobile games
- Development of a classification of games to choose representative games and identify system and user factors
- Building a questionnaire covering a large space of relevant quality dimensions
- Identification of quality-relevant perceptual dimensions and analysis of their impact on the overall quality
- Analyzing the performance of current objective metrics which were proposed for different contents and services in mobile gaming
- Building a QoE model based on game, system and network characteristics as well as user and context factors
|Project Number:||MO 1038/21-1|
List of Publications
|Author||Zadtootaghaj, Saman and Schmidt, Steven and Möller, Sebastian|
|Title of Book||2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX)|
|Abstract||Recent advances of streaming services and the upcoming new generation of mobile networks, 5G, offering low end-to-end delay as well as high bandwidths, promise a bright future for cloud gaming applications. Cloud gaming, in the contrary to traditional gaming services, suffers not only from system factors on the client, but is also affected significantly by the network, server specification and encoding parameters. In this paper, we present the results of a subjective experiment aiming to investigate the impact of two influencing factors, frame rate and bit rate, on the gaming Quality of Experience. The results reveal that a trade-off between an acceptable video quality and interaction quality exists. In case of very low bit rates, lowering the frame rate can improve the video quality while at some point, jerkiness becomes visible which affects the video quality negatively and the control over the game will be strongly reduced. Furthermore, even though in the gaming community a frame rate of 60 fps is desired, no significant difference for quality ratings, as well as performance ratings, was found between 60 fps and 25 fps. Therefore, it would be highly valuable for service providers to find an ideal strategy for this issue. In addition, we investigate the impact of video encoding on gaming experience dimensions. Finally, a first attempt to model the impact of two influencing factors on overall quality will be presented.|