- Image and Video Quality Assessment
- Caching and Content Delivery
- Peer-to-Peer Network Technologies
- Network Traffic and Congestion Control
- Multimedia Communication and Technology
- Mobile Crowdsensing and Crowdsourcing
- Video Coding and Compression Technologies
- Software-Defined Networks and 5G
- Green IT and Sustainability
- IoT and Edge/Fog Computing
- IoT Networks and Protocols
- Complex Network Analysis Techniques
- Internet Traffic Analysis and Secure E-voting
- Energy Harvesting in Wireless Networks
- Cloud Computing and Resource Management
- Data Visualization and Analytics
- Network Security and Intrusion Detection
- Open Source Software Innovations
- Advanced MIMO Systems Optimization
- Bluetooth and Wireless Communication Technologies
- Opportunistic and Delay-Tolerant Networks
- Network Time Synchronization Technologies
- Advanced Data Compression Techniques
- Advanced Wireless Network Optimization
- Advanced Optical Network Technologies
University of Würzburg
2015-2025
Czech Academy of Sciences, Institute of Computer Science
2022
Technische Universität Ilmenau
2019
Gorgias Press (United States)
2019
University of Duisburg-Essen
2014-2018
Birmingham City University
2014
Ewha Womans University
2014
Korean Bible University
2014
The University of Tokyo
2014
University of Klagenfurt
2013
Quality of experience ties together user perception, experience, and expectations to application network performance, typically expressed by quality service parameters. Quantitative relationships between QoE QoS are required in order be able build effective control mechanisms onto measurable Against this background, article proposes a generic formula which parameters connected through an exponential relationship, called IQX hypothesis. The relates changes with respect the current level QoE,...
Changing network conditions pose severe problems to video streaming in the Internet. HTTP adaptive (HAS) is a technology employed by numerous services that relieves these issues adapting current conditions. It enables service providers improve resource utilization and Quality of Experience (QoE) incorporating information from different layers order deliver adapt its best possible quality. Thereby, it allows taking into account end user device capabilities, available quality levels,...
This paper addresses the challenge of assessing and modeling Quality Experience (QoE) for online video services that are based on TCP-streaming. We present a dedicated QoE model You Tube takes into account key influence factors (such as stalling events caused by network bottlenecks) shape quality perception this service. As second contribution, we propose generic subjective assessment methodology multimedia applications (like video) is crowd sourcing - highly cost-efficient, fast flexible...
Quality of Experience (QoE) in multimedia applications is closely linked to the end users' perception and therefore its assessment requires subjective user studies order evaluate degree delight or annoyance as experienced by users. QoE crowdtesting refers using crowdsourcing, where anonymous test subjects conduct tests remotely their preferred environment. The advantages lie not only reduced time costs for tests, but also a large diverse panel international, geographically distributed users...
End user quality perception in the context of Internet applications is often characterized by waiting times before service consumption as well interruptions during consumption. In particular case bad network conditions, and providers have to trade off between these two impairment types, i.e. devil deep blue sea. this paper we investigate tradeoff order guide design development management approaches. The contribution twofold. Firstly, quantify impact initial delays on perceived Quality...
Cloud Gaming is a new kind of service, which combines the successful concepts Computing and Online Gaming. It provides entire game experience to users remotely from data center. The player no longer dependent on specific type or quality gaming hardware, but able use common devices. end device only needs broadband internet connection ability display High Definition (HD) video. While this may reduce hardware costs for increase revenue developers by leaving out retail chain, it also raises...
The term Software Defined Networking (SDN) is prevalent in today's discussion about future communication networks. As with any new or paradigm, however, no consistent definition regarding this technology has formed. fragmented view on SDN results legacy products being passed off by equipment vendors as SDN, academics mixing up the attributes of those network virtualization, and users not fully understanding benefits. Therefore, establishing a widely adopted beyond laboratories insular...
A considerable share of applications such as web or e-mail browsing, online picture viewing and file downloads imply waiting times for their users, which is due to the turn-taking information requests by user correspoding response until each request fulfilled. Thus, end-user quality perception in context interactive data services dominated times; longer latter, less satisfied becomes. As opposed heavily researched multimedia experience, still not strongly explored Quality Experience (QoE)....
When it comes to analysis and interpretation of the results subjective QoE studies, one often witnesses a lack attention diversity in user ratings. In extreme cases, solely Mean Opinion Scores (MOS) are reported, causing loss important information on rating diversity. this paper, we emphasize importance considering Standard deviation (SOS) analyze characteristics measure. As result, formulate SOS hypothesis which postulates square relationship between MOS SOS. We demonstrate validity...
Since Jeff Howe introduced the term "crowdsourcing" in 2006 for first time, crowd sourcing has be come a growing market current Internet. Thousands of workers categorize images, write articles or perform other small tasks on platforms like Amazon Mechanical Turk (MTurk), Micro Short Task. In this work, we want to give an inside view usage data from and show that there are significant differences well studied MTurk. Further, have look at perspective worker, employer platform owner, order...
Video streaming applications are a major driver for the evolution of future Internet. In this paper we introduce framework QoE management video systems based on H.264/SVC codec, scalable extension H.264/AVC. A relevant feature is to control user perceived quality experience (QoE) by exploiting parameters offered SVC. proper design mechanism requires quantification main influence QoE. For purpose, conducted measurement study and quantified (i) resolution, (ii) scaling method, (iii) frame rate...
As the Internet of Things (IoT) continues to gain traction in telecommunication networks, a very large number devices are expected be connected and used near future. In order appropriately plan dimension network, as well back-end cloud systems resulting signaling load, traffic models employed. These designed accurately capture predict properties IoT concise manner. To achieve this, Poisson process approximations, based on Palm–Khintchine theorem, have often been past. Due scale (and...
HTTP Adaptive Streaming (HAS) is employed by more and video streaming services in the Internet. It allows to adapt downloaded quality current network conditions, thus, avoids stalling (i.e., playback interruptions) greatest possible extend. The adaptation of streams done switching between different representation levels, which influences user perceived stream. In this work, influence several parameters, namely, switch amplitude level difference), frequency, recency effects, on Quality...
Quality of Experience (QoE) has received much attention over the past years and become a prominent issue for delivering services applications. A significant amount research been devoted to understanding, measuring, modelling QoE variety media services. The next logical step is actively exploit that accumulated knowledge improve manage quality multimedia services, while at same time ensuring efficient cost-effective network operations. Moreover, with many different players involved in...
User-centric service and application management focuses on the quality of experience (QoE) as perceived by end user. Thereby, goal is to maximize QoE while ensuring fairness among users, e.g., for resource allocation scheduling in shared systems. Although literature suggests consider consequently fairness, there currently no accepted definition fairness. The contribution this letter a generic <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Over the last decade, Quality of Experience (QoE) has become guiding paradigm for enabling a more user-centric understanding quality communication networks and services. The intensifying competition among ISPs exponentially increasing traffic volumes caused by online video platforms like YouTube is forcing service providers to integrate QoE into their corporate DNA. This paper investigates problem monitoring from an access provider's perspective. To this end, we present three novel methods...
WhatsApp is a very popular mobile messaging application, which dominates todays communication. Especially the feature of group chats contributes to its success and changes way people communicate. The group-based communication paradigm investigated in this work, particularly focusing on usage WhatsApp, chats, implications network traffic.