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Fiedler, Markus
Publications (10 of 187) Show all publications
Fiedler, M., Moller, S., Reichl, P. & Xie, M. (2018). A Glance at the Dagstuhl Manifesto 'QoE Vadis?'. In: 2018 10th International Conference on Quality of Multimedia Experience, QoMEX 2018: . Paper presented at 10th International Conference on Quality of Multimedia Experience, QoMEX 2018, 29 May 2018 through 1 June 2018, Sardinia, Italy. Institute of Electrical and Electronics Engineers Inc., Article ID 8463374.
Open this publication in new window or tab >>A Glance at the Dagstuhl Manifesto 'QoE Vadis?'
2018 (English)In: 2018 10th International Conference on Quality of Multimedia Experience, QoMEX 2018, Institute of Electrical and Electronics Engineers Inc. , 2018, article id 8463374Conference paper, Published paper (Refereed)
Abstract [en]

This short paper presents the recently published Dagstuhl Manifesto 'QoE Vadis?'. The Manifesto is the result of a set of three Dagstuhl Seminars and one Dagstuhl Perspectives Workshop, aimed at shaping understanding, development and application of the Quality of Experience (QoE) notion and concept. Its task is to convey the current status, promising developments and future projections for different stakeholders. The latter are summarised in a set of eleven recommendations to academia, industry and funding organisations. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Business Aspects, Multimedia, Quality Feedback, Quality Management, Quality of Experience, Recommendations, Socioeconomic Aspects, User Experience
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-17147 (URN)10.1109/QoMEX.2018.8463374 (DOI)2-s2.0-85054407120 (Scopus ID)9781538626054 (ISBN)
Conference
10th International Conference on Quality of Multimedia Experience, QoMEX 2018, 29 May 2018 through 1 June 2018, Sardinia, Italy
Available from: 2018-10-19 Created: 2018-10-19 Last updated: 2018-10-19Bibliographically approved
Eivazzadeh, S., Sanmartin Berglund, J., Larsson, T., Fiedler, M. & Anderberg, P. (2018). Most Influential Qualities in Creating Satisfaction Among the Users of Health Information Systems: A Study in Seven EU Countries. JMIR Medical Informatics
Open this publication in new window or tab >>Most Influential Qualities in Creating Satisfaction Among the Users of Health Information Systems: A Study in Seven EU Countries
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2018 (English)In: JMIR Medical InformaticsArticle in journal (Refereed) Epub ahead of print
Abstract [en]

Background:

Several models suggest how the qualities of a product or service influence user satisfaction. Models, such as the Customer Satisfaction Index (CSI), Technology Acceptance Model (TAM), and Delone and McLean Information Systems Success (D&M IS), demonstrate those relations and have been used in the context of health information systems.

Objective:

We want to investigate which qualities foster greater satisfaction among patient and professional users. In addition, we are interested in knowing to what extent improvement in those qualities can explain user satisfaction and if this makes user satisfaction a proxy indicator of those qualities.

Methods:

The Unified eValuation using ONtology (UVON) method was utilised to construct an ontology of the required qualities for seven e-health applications being developed in the FI-STAR project, a European Union (EU) project in e-health. The e-health applications were deployed across seven EU countries. The ontology included and unified the required qualities of those systems together with the aspects suggested by the Model for ASsessment of Telemedicine applications (MAST) evaluation framework. Two similar questionnaires, for 87 patient users and 31 health professional users, were elicited from the ontology. In the questionnaires, user was asked if the system has improved the specified qualities and if the user was satisfied with the system. The results were analysed using Kendall correlation coefficients matrices, incorporating the quality and satisfaction aspects. For the next step, two Partial Least Squares Structural Equation Modelling (PLS-SEM) path models were developed using the quality and satisfaction measure variables and the latent construct variables that were suggested by the UVON method.

Results:

Most of the quality aspects grouped by the UVON method are highly correlated. Strong correlations in each group suggest that the grouped qualities can be measures which reflect a latent quality construct. The PLS-SEM path analysis for the patients reveals that the effectiveness, safety, and efficiency of treatment provided by the system are the most influential qualities in achieving and predicting user satisfaction. For the professional users, effectiveness and affordability are the most influential. The parameters of the PLS-SEM that are calculated allow for the measurement of a user satisfaction index similar to CSI for similar health information systems.

Conclusions:

For both patients and professionals, the effectiveness of systems highly contributes to their satisfaction. Patients care about improvements in safety and efficiency, while professionals care about improvements in the affordability of treatments with health information systems. User satisfaction is reflected more in the users' evaluation of system output and fulfilment of expectations, but slightly less in how far the system is from ideal. Investigating satisfaction scores can be a simple, fast way to infer if the system has improved the abovementioned qualities in treatment and care.

Place, publisher, year, edition, pages
JMIR Publications, 2018
Keywords
Health Information Systems, Telemedicine, Evaluation Studies as Topic, Consumer Behavior, Treatment Outcome, Safety, Efficiency, Health Care Costs, Ontology Engineering, Equation Models
National Category
Other Health Sciences
Identifiers
urn:nbn:se:bth-16998 (URN)10.2196/11252 (DOI)
Projects
MD3S
Note

Open access

Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2018-09-13Bibliographically approved
Fotrousi, F., Fricker, S. & Fiedler, M. (2018). The effect of requests for user feedback on Quality of Experience. Software quality journal, 26(2), 385-415
Open this publication in new window or tab >>The effect of requests for user feedback on Quality of Experience
2018 (English)In: Software quality journal, ISSN 0963-9314, E-ISSN 1573-1367, Vol. 26, no 2, p. 385-415Article in journal (Refereed) Published
Abstract [en]

Companies are interested in knowing how users experience and perceive their products. Quality of Experience (QoE) is a measurement that is used to assess the degree of delight or annoyance in experiencing a software product. To assess QoE, we have used a feedback tool integrated into a software product to ask users about their QoE ratings and to obtain information about their rationales for good or bad QoEs. It is known that requests for feedback may disturb users; however, little is known about the subjective reasoning behind this disturbance or about whether this disturbance negatively affects the QoE of the software product for which the feedback is sought. In this paper, we present a mixed qualitative-quantitative study with 35 subjects that explore the relationship between feedback requests and QoE. The subjects experienced a requirement-modeling mobile product, which was integrated with a feedback tool. During and at the end of the experience, we collected the users' perceptions of the product and the feedback requests. Based on the users' rational for being disturbed by the feedback requests, such as "early feedback," "interruptive requests," "frequent requests," and "apparently inappropriate content," we modeled feedback requests. The model defines feedback requests using a set of five-tuple variables: "task," "timing" of the task for issuing the feedback requests, user's "expertise-phase" with the product, the "frequency" of feedback requests about the task, and the "content" of the feedback request. Configuration of these parameters might drive the participants' perceived disturbances. We also found that the disturbances generated by triggering user feedback requests have negligible impacts on the QoE of software products. These results imply that software product vendors may trust users' feedback even when the feedback requests disturb the users.

Place, publisher, year, edition, pages
SPRINGER, 2018
Keywords
Quality of experience, QoE, User feedback, User perception, Human factors
National Category
Software Engineering
Identifiers
urn:nbn:se:bth-16526 (URN)10.1007/s11219-017-9373-7 (DOI)000433521200007 ()
Available from: 2018-06-18 Created: 2018-06-18 Last updated: 2018-06-18Bibliographically approved
Popescu, A., Yao, Y., Fiedler, M. & Ducloux, X. (2018). Video Distribution Networks: Models and Performance. In: Adrian Popescu (Ed.), Greening Video Distribution Networks: Energy-Efficient Internet Video Delivery (pp. 227). Springer
Open this publication in new window or tab >>Video Distribution Networks: Models and Performance
2018 (English)In: Greening Video Distribution Networks: Energy-Efficient Internet Video Delivery / [ed] Adrian Popescu, Springer, 2018, p. 227-Chapter in book (Refereed)
Abstract [en]

The creation, distribution and delivery of video content is a sophisticated process with elements like video acquisition, preprocessing and encoding, content production and packaging as well as distribution to customers. IP networks are usually used for the transfer of video signals. The treatment of video content is also very complex, and we have a multidimensional process with elements like content acquisition, content exchange and content distribution. The focus of the chapter is on the presentation of models that can be used to characterize the main elements in a video distribution chain. These models are about video coding and compression, video streaming, video traffic models, energy consumption models, system performance, concepts of performance optimization and QoE- and energy-optimal streaming.

Place, publisher, year, edition, pages
Springer, 2018
Series
Computer Communications and Networks, ISSN 1617-7975
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-17224 (URN)10.1007/978-3-319-71718-0_3 (DOI)978-3-319-71718-0 (ISBN)
Available from: 2018-11-05 Created: 2018-11-05 Last updated: 2018-11-07Bibliographically approved
Yao, Y., Popescu, A., Fiedler, M. & Ljung, R. (2017). On the Performance of Video Streaming in Energy-Aware Wireless Mesh Networks. In: European Conference on Networks and Communications (EuCNC) 2017: . Paper presented at European Conference on Networks and Communications (EuCNC), Oulu, Finland. IEEE
Open this publication in new window or tab >>On the Performance of Video Streaming in Energy-Aware Wireless Mesh Networks
2017 (English)In: European Conference on Networks and Communications (EuCNC) 2017, IEEE, 2017Conference paper, Published paper (Refereed)
Abstract [en]

Mobile multimedia has today become a promising application for end users and service providers. With reference to the existing systems for mobile communications, this application further demands for solving several technical problems, especially regarding video streaming over wireless networks. An interesting approach is in form ofWireless Mesh Network (WMN) based networks, where the individual video flows operate in an end-to-end (e2e) manner along a particular networking scenario including several mesh routers. That means, a particular mesh router may be traversed by multiple video flows. This situation may become even more complicated in the case of a large amount of packet retransmissions, which may deteriorate the performance of video flows. To investigate this problem, a two-level Modulated Markov Poisson Process (MMPP) based queueing model is built up and the transport performance of e2e video streaming in WMN based mobile multimedia system is analysed. Four metrics are used to study the system performance, namely e2e throughput, e2e delay, e2e error-rate and traffic-related energy consumption. Numerical analysis and evaluation studies are done. Based on the reported results, two different solutions are suggested and discussed with regard to the trade-off among these metrics.

Place, publisher, year, edition, pages
IEEE, 2017
Series
European Conference on Networks and Communications, ISSN 2475-6490, E-ISSN 2575-4912
Keywords
Streaming media, Energy consumption, Power demand, Routing, Mobile communication, Measurement, Mobile handsets
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-15640 (URN)10.1109/EuCNC.2017.7980771 (DOI)000425922900130 ()978-1-5386-3873-6 (ISBN)
Conference
European Conference on Networks and Communications (EuCNC), Oulu, Finland
Projects
CONVINcE
Available from: 2017-12-12 Created: 2017-12-12 Last updated: 2018-05-23Bibliographically approved
Nawaz, O., Minhas, T. N. & Fiedler, M. (2017). QoE based comparison of H.264/AVC and WebM/VP8 in an error-prone wireless network. In: Chemouil P.,Simoes P.,Madeira E.,Secci S.,Monteiro E.,Gaspary L.P.,dos Santos C.R.P.,Charalambides M. (Ed.), Proceedings of the IM 2017 - 2017 IFIP/IEEE International Symposium on Integrated Network and Service Management: . Paper presented at 15th IFIP/IEEE International Symposium on Integrated Network and Service Management, IM 2017, Lisbon (pp. 1005-1010). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>QoE based comparison of H.264/AVC and WebM/VP8 in an error-prone wireless network
2017 (English)In: Proceedings of the IM 2017 - 2017 IFIP/IEEE International Symposium on Integrated Network and Service Management / [ed] Chemouil P.,Simoes P.,Madeira E.,Secci S.,Monteiro E.,Gaspary L.P.,dos Santos C.R.P.,Charalambides M., Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1005-1010Conference paper, Published paper (Refereed)
Abstract [en]

Quality of Experience (QoE) management is a prime topic of research community nowadays as video streaming, online gaming and security applications are completely reliant on the network service quality. Moreover, there are no standard models to map Quality of Service (QoS) into QoE. HTTP media streaming is primarily used for such applications due to its coherence with the Internet and simplified management. The most common video codecs used for video streaming are H.264/AVC and Google's VP8. In this paper, we have analyzed the performance of these two codecs from the perspective of QoE. The most common end-user medium for accessing video content is via home based wireless networks. We have emulated an error-prone wireless network with different scenarios involving packet loss, packet delay and delay variation. The focus of this paper is evaluating the end user satisfaction with the multimedia content by subjective assessment using Mean Opinion Score (MOS). We have observed the overall superiority of H.264/AVC but the VP8 codec strongly gains ground in highly error-prone networks in terms of user satisfaction. © 2017 IFIP.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Keywords
H.264/AVC, Multimedia communication, QoE management, Quality of Experience, WebM(VP8), Errors, HTTP, Human computer interaction, Media streaming, Motion Picture Experts Group standards, Multimedia systems, Packet networks, Video signal processing, Video streaming, Wireless networks, Multi-media communications, Qoe managements, Quality of experience (QoE), Quality of service
National Category
Communication Systems
Identifiers
urn:nbn:se:bth-15217 (URN)10.23919/INM.2017.7987426 (DOI)2-s2.0-85029430735 (Scopus ID)9783901882890 (ISBN)
Conference
15th IFIP/IEEE International Symposium on Integrated Network and Service Management, IM 2017, Lisbon
Available from: 2017-09-29 Created: 2017-09-29 Last updated: 2017-09-29Bibliographically approved
Fiedler, M., De Moor, K., Ravuri, H., Tanneedi, P. & Chandiri, M. (2017). Users On The Move: On Relationships Between QoE Ratings, Data Volumes and Intentions to Churn. In: Proc. 2017 IEEE 42nd Conference on Local Computer Networks Workshops (LCN Workshops): Workshop On User MObility and VEhicular Networks (ON-MOVE). Paper presented at IEEE 42nd Conference on Local Computer Networks Workshops (LCN Workshops), Singapore (pp. 97-102). IEEE
Open this publication in new window or tab >>Users On The Move: On Relationships Between QoE Ratings, Data Volumes and Intentions to Churn
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2017 (English)In: Proc. 2017 IEEE 42nd Conference on Local Computer Networks Workshops (LCN Workshops): Workshop On User MObility and VEhicular Networks (ON-MOVE), IEEE, 2017, p. 97-102Conference paper, Published paper (Refereed)
Abstract [en]

For a long time, the risk of customer churn, i.e. to leave an operator, has been used as argument in favor of Quality of Experience (QoE) research. However, the understanding of how churn behavior and QoE are related is still limited. This is problematic, as customer retention and churn prediction have grown in importance in face of ever-growing competition on the telecom market. The work presented in this paper aims to make a contribution in this respect, by exploring the relationships between QoE ratings, data volumes and churn risk through a longitudinal user study. Using an Experience Sampling Method-inspired approach we have been collecting weekly feedback on experienced quality, annoyance and intentions to churn from 22 users for up to eight weeks. Additionally, measurements of weekly used data volumes were collected. We observed churning behavior for 3 out of 22 participants and analyze the rating and data usage profiles of churners against non-churners. Furthermore, we investigate correlations of ratings and volumes, and find that “annoyed churners surf less”. Our findings point out warning signals for potential user churn as well as promising directions for future studies.

Place, publisher, year, edition, pages
IEEE, 2017
Keywords
Quality of Experience, user ratings, customer churn, data volumes
National Category
Communication Systems
Identifiers
urn:nbn:se:bth-15621 (URN)10.1109/LCN.Workshops.2017.70 (DOI)000418465100013 ()978-1-5090-6583-7 (ISBN)
Conference
IEEE 42nd Conference on Local Computer Networks Workshops (LCN Workshops), Singapore
Projects
BigData@BTH
Funder
Knowledge Foundation, 2014-0032
Available from: 2017-12-13 Created: 2017-12-13 Last updated: 2018-02-02Bibliographically approved
Vo, N.-S., Duong, T. Q., Zepernick, H.-J. & Fiedler, M. (2016). A Cross-Layer Optimized Scheme and Its Application in Mobile Multimedia Networks With QoS Provision. IEEE Systems Journal, 10(2), 817-830
Open this publication in new window or tab >>A Cross-Layer Optimized Scheme and Its Application in Mobile Multimedia Networks With QoS Provision
2016 (English)In: IEEE Systems Journal, ISSN 1932-8184, E-ISSN 1937-9234, Vol. 10, no 2, p. 817-830Article in journal (Refereed) Published
Abstract [en]

To cope with the rapid growth of multimedia applications that requires dynamic levels of quality of service (QoS), cross-layer (CL) design, where multiple protocol layers are jointly combined, has been considered to provide diverse QoS provisions for mobile multimedia networks. However, there is a lack of a general mathematical framework to model such CL scheme in wireless networks with different types of multimedia classes. In this paper, to overcome this shortcoming, we therefore propose a novel CL design for integrated real-time/non-real-time traffic with strict preemptive priority via a finite-state Markov chain. The main strategy of the CL scheme is to design a Markov model by explicitly including adaptive modulation and coding at the physical layer, queuing at the data link layer, and the bursty nature of multimedia traffic classes at the application layer. Utilizing this Markov model, several important performance metrics in terms of packet loss rate, delay, and throughput are examined. In addition, our proposed framework is exploited in various multimedia applications, for example, the end-to-end real-time video streaming and CL optimization, which require the priority-based QoS adaptation for different applications. More importantly, the CL framework reveals important guidelines as to optimize the network performance.

Place, publisher, year, edition, pages
IEEE, 2016
Keywords
Cross-layer Optimization, Delay, Multimedia Applications, Quality of Service, Throughput
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-6389 (URN)10.1109/JSYST.2014.2377560 (DOI)000383258600039 ()
Available from: 2015-04-22 Created: 2015-04-21 Last updated: 2017-12-04Bibliographically approved
Ballesteros, L. G., Ickin, S., Fiedler, M., Markendahl, J., Tollmar, K. & Wac, K. (2016). Energy Saving Approaches for Video Streaming on Smartphone based on QoE Modeling. In: 2016 13TH IEEE ANNUAL CONSUMER COMMUNICATIONS & NETWORKING CONFERENCE (CCNC): . Paper presented at 13th IEEE Annual Consumer Communications and Networking Conference (CCNC), JAN 06-13, 2016, Las Vegas, NV. IEEE Communications Society
Open this publication in new window or tab >>Energy Saving Approaches for Video Streaming on Smartphone based on QoE Modeling
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2016 (English)In: 2016 13TH IEEE ANNUAL CONSUMER COMMUNICATIONS & NETWORKING CONFERENCE (CCNC), IEEE Communications Society, 2016Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we study the influence of video stalling on QoE. We provide QoE models that are obtained in realistic scenarios on the smartphone, and provide energy-saving approaches for smartphone by leveraging the proposed QoE models in relation to energy. Results show that approximately 5J is saved in a 3 minutes video clip with an acceptable Mean Opinion Score (MOS) level when the video frames are skipped. If the video frames are not skipped, then it is suggested to avoid freezes during a video stream as the freezes highly increase the energy waste on the smartphones.

Place, publisher, year, edition, pages
IEEE Communications Society, 2016
Keywords
QoE, QoS, Energy, Mobile, Video
National Category
Media and Communication Technology
Identifiers
urn:nbn:se:bth-13055 (URN)000382042200018 ()978-1-4673-9292-1 (ISBN)
Conference
13th IEEE Annual Consumer Communications and Networking Conference (CCNC), JAN 06-13, 2016, Las Vegas, NV
Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-14Bibliographically approved
Minhas, T. N., Shahid, M., Lövström, B., Rossholm, A., Zepernick, H.-J. & Fiedler, M. (2016). QoE rating performance evaluation of ITU-T recommended video quality metrics in the context of video freezes. Australian Journal of Electrical and Electronics Engineering, 13(2), 122-131
Open this publication in new window or tab >>QoE rating performance evaluation of ITU-T recommended video quality metrics in the context of video freezes
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2016 (English)In: Australian Journal of Electrical and Electronics Engineering, ISSN 1448-837X, Vol. 13, no 2, p. 122-131Article in journal (Refereed) Published
Abstract [en]

In real-time video streaming, video quality can be degraded due to network performance issues. Among other artefacts, video freezing and video jumping are factors that influence user experience. Service providers, operators and manufacturers are interested in evaluating the quality of experience (QoE) objectively because subjective assessment of QoE is expensive and, in many user cases, subjective assessment is not possible to perform. Different algorithms have been proposed and implemented in this regard. Some of them are in the recommendation list of the ITU Telecommunication Standardization Sector (ITU-T). In this paper, we study the effect of the freezing artefact on user experience and compare the mean opinion score of these videos with the results of two algorithms, the perceptual evaluation of video quality (PEVQ) and temporal quality metric (TQM). Both metrics are part of the ITU-T Recommendation J.247 Annex B and C. PEVQ is a full-reference video quality metric, whereas TQM is a no-reference quality metric. Another contribution of this paper is the study of the impact of different resolutions and frame rates on user experience and how accurately PEVQ and TQM measure varying frame rates.

Place, publisher, year, edition, pages
Taylor & Francis, 2016
Keywords
Freezing; Image quality; Quality of service; Video signal processing; Video streaming, Objective video quality; Quality of experience (QoE); Subjective video quality; Temporal quality; Video quality, Quality control
National Category
Signal Processing Communication Systems
Identifiers
urn:nbn:se:bth-13135 (URN)10.1080/1448837X.2015.1094855 (DOI)2-s2.0-84965031048 (Scopus ID)
Available from: 2016-10-04 Created: 2016-10-03 Last updated: 2016-12-19Bibliographically approved
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