QoEWeb

QoEWeb: Quality of Experience and User Behaviour Modelling for Web Traffic

QoEWeb Project Team

Head	Tobias Hoßfeld, University of Würzburg
	Markus Fiedler, Blekinge Institute of Technology
	Denis Collange, France Telecom SA
	Zbigniew Kotulski, Warsaw University of Technology

Researchers	Daniel Schlosser
	Valentin Burger
	Patrik Arlos
	Junaid Shaikh
	Frederic Guyard
	Frédérique Millo
	Wojciech Mazurczyk
	Tomasz Ciszkowski

Summary

Increasingly many ICT solutions, services and applications, use the web browser as well-known and well-understood user interface. Typically, such services work in an interactive manner, i.e. the user performs some action (clicks on some link or button, or enters some information) and needs to wait for the response. As long as the latter arrives within a certain time horizon, e.g. within the reaction time of one second, the user feels the system to react immediately. However, long or heavily varying response times upon user action make the user suffer. The question is now: How patient is a user in such a case, i.e. how does her/his perception sink with time and/or the number of actions performed in case of bad network conditions? This question needs to be related to the type of application, which means considering the expected performance for a fixed web page, a video, a request to a search engine, etc.

For ISPs, the main application is to detect performance problems (based on user perception) on their network. In case of trouble, they can apply tools to localize, diagnose and correct the problem. These tools build on network measurements (QoS), which need to be linked to user perception (QoE). Some dependencies between network-level performance (loss rate, throughput, etc.) and application-level performance (response time) criteria may be modelled by TCP models. For instance, a large packet loss rate, reflecting unreliable network conditions, leads to very variable response times. Some transfers are still quickly served, while others observe very long response times. So the users should observe varying response time which may be more disturbing than constant long response times. However, a more detailed (multi-factorial) statistical and time-dependent analysis of correlations between QoS and QoE is needed to detect other phenomena such as the decrease of user satisfaction until a point when the service in question is abandoned. Once this timely behaviour is known and modelled, it defines the time frame on which the provider needs to act in order to prevent the users from giving up.

Bad QoE can have serious consequences for an Internet Service, Application Service and Hosting Provider. A user that “cannot get its job done” might consider to “churn”, i.e. to abandon the provider/operator in question. Complaining users are the top of an iceberg, many just leave without further notice towards the operator. However, they might spread bad gossip about their negative experience. In other words, the reputation of the operator/provider (from the user point of view) will be affected in a negative way.

The aim of the proposed specific EuroNF project is to model user perceived quality and user behaviour for web traffic. To be more precise, our main objectives are:

Quantification of QoE for web traffic, based on passive measurements (observations) within an operator’s network and active measurements in a test laboratory
Description of an appropriate model for the (timely) behaviour of web user satisfaction / impatience which builds upon feedback of the user-perceived quality, based on the measurements
Application of the derived user model to identify impact of QoE on system performance in business environments like wireless networks with shared capacity
Quantification of reputation management applying the derived model in order to allow provider/operator to react before the user-related reputation gets critical

Phone Conferences

September 18th, 2-3pm, preparation of Kick-off meeting in Athens
November 12th, 9-10am, discussion of survey paper
December 10th, 2-3pm, status survey paper and measurements
January 23rd, 3:30-4:30pm, first draft ready
February 6th, 10-12am, discussion on current draft
March 13th, 10-11am, current status of reputation and IEEE survey paper, activities in WP1 and WP3
March 30th, 2-3pm, mid-term report, IEEE survey paper
April 29th, 2-3pm, active and passive measurements, simulation framework for shared system and first results
June 19th, 10-11am, current status of WPs
July 28th, 5:30pm-6:30pm, after the EuroView workshop, current status of WPs

Meetings

Kick-Off meeting, October 15th, 2008, co-located with Euro-NF workshop on socio-economics in Athens
Members of QoEWeb team will participate at the Dagstuhl Seminar From Quality of Service to Quality of Experience, May 5th - 8th, 2009

Talks

Tobias Hoßfeld, An overview on the QoEWeb Project, 1st EuroNF Socio Economics Workshop, October 16th, 2008, Athens, Greece; slides available as ppt or pdf
Tomasz Ciszkowski, Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning, 2nd Euro-NF Workshop on Future Internet Architectures: New Trends in Service Architectures, Santander, Spain, June 9th, 2009
Members of QoEWeb team participated at workshop on "Quality of Experience (QoE)", collocated with 21st International Teletraffic Congress (ITC 21) - Traffic and Performance Issues in Networks of the Future, 18th September 2009, Telecom ParisTech, Paris 13, France
- Sergio Beker and Frederic Guyard (FT): Towards a QoE Framework
- Markus Fiedler (BTH): QoE quantification and feedback
- Thomas Zinner, Tobias Hoßfeld (UWUERZ): Controlling QoE of Scalable Video Codecs for Future Video Streaming Systems

Other Stuff

restricted access to the shared web repository.

description of the project in the public Euro-NF knowledge map

Article[ to top ]

A Generic Quantitative Relationship between Quality of Experience and Quality of Service. Fiedler, Markus; Hoßfeld, Tobias; Tran-Gia, Phuoc. In IEEE Network Special Issue on Improving QoE for Network Services. 2010.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
- [ Download ]
Quality of Experience (QoE) ties together user perception, experience and expectations to application and network performance, typically expressed by Quality of Service (QoS) parameters. Quantitative relationships between QoE and QoS are required in order to be able to build effective QoE control mechanisms onto measurable QoS parameters. On this background, this paper proposes a generic formula in which QoE and QoS parameters are connected through an exponential relationship, called IQX hypothesis. The formula relates changes of QoE with respect to QoS to the current level of QoE, is simple to match, and its limit behaviours are straighforward to interpret. It validates the IQX hypothesis for streaming services, where QoE in terms of Mean Opinion Scores (MOS) is expressed as functions of loss and reordering ratio, the latter of which is caused by jitter. For web surfing as the second application area, matchings provided by the IQX hypothesis are shown to outperform previously published logarithmic functions. We conclude that the IQX hypothesis is a strong candidate to be taken into account when deriving relationships between QoE and QoS parameters.

@article{info3-article-2010-71, abstract = {Quality of Experience (QoE) ties together user perception, experience and expectations to application and network performance, typically expressed by Quality of Service (QoS) parameters. Quantitative relationships between QoE and QoS are required in order to be able to build effective QoE control mechanisms onto measurable QoS parameters. On this background, this paper proposes a generic formula in which QoE and QoS parameters are connected through an exponential relationship, called IQX hypothesis. The formula relates changes of QoE with respect to QoS to the current level of QoE, is simple to match, and its limit behaviours are straighforward to interpret. It validates the IQX hypothesis for streaming services, where QoE in terms of Mean Opinion Scores (MOS) is expressed as functions of loss and reordering ratio, the latter of which is caused by jitter. For web surfing as the second application area, matchings provided by the IQX hypothesis are shown to outperform previously published logarithmic functions. We conclude that the IQX hypothesis is a strong candidate to be taken into account when deriving relationships between QoE and QoS parameters.}, author = {Fiedler, Markus and Hoßfeld, Tobias and Tran-Gia, Phuoc}, journal = {IEEE Network Special Issue on Improving QoE for Network Services}, keywords = {sys:hidden:article}, month = {06}, title = {A Generic Quantitative Relationship between Quality of Experience and Quality of Service}, year = 2010 }

%0 Journal Article %1 info3-article-2010-71 %A Fiedler, Markus %A Hoßfeld, Tobias %A Tran-Gia, Phuoc %D 2010 %J IEEE Network Special Issue on Improving QoE for Network Services %T A Generic Quantitative Relationship between Quality of Experience and Quality of Service %X Quality of Experience (QoE) ties together user perception, experience and expectations to application and network performance, typically expressed by Quality of Service (QoS) parameters. Quantitative relationships between QoE and QoS are required in order to be able to build effective QoE control mechanisms onto measurable QoS parameters. On this background, this paper proposes a generic formula in which QoE and QoS parameters are connected through an exponential relationship, called IQX hypothesis. The formula relates changes of QoE with respect to QoS to the current level of QoE, is simple to match, and its limit behaviours are straighforward to interpret. It validates the IQX hypothesis for streaming services, where QoE in terms of Mean Opinion Scores (MOS) is expressed as functions of loss and reordering ratio, the latter of which is caused by jitter. For web surfing as the second application area, matchings provided by the IQX hypothesis are shown to outperform previously published logarithmic functions. We conclude that the IQX hypothesis is a strong candidate to be taken into account when deriving relationships between QoE and QoS parameters.
Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning. Ciszkowski, Tomasz; Mazurczyk, Wojciech; Kotulski, Zbigniew; Hoßfeld, Tobias; Fiedler, Markus; Collange, Denis. In Special Issue of the Springer Telecommunication Systems Journal: Future Internet Services and Architectures - Trends and Visions, print available in 2013, 51, pp. 283–295. 2010.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
- [ Download ]
This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in the Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield a general scoring of a particular behavior. Thus, they are likely to become an important ingredient of the Future Internet. Parameters under evaluation by a reputation system may vary greatly and, particularly, may be chosen to assess the users' satisfaction with (composite) web services. Currently, this satisfaction is usually expressed by QoE, which represents subjective users' opinions. The goal of this paper is to present a novel framework of web services where a reputation system is incorporated for tracking and predicting of users' satisfaction. This approach is a beneficial tool which enables providers to facilitate service adaptation according to users' expectations and maintain QoE at a satisfactory level. Presented reputation systems operate in an environment of composite services that integrate client and server-side. This approach is highly suitable for effective QoE differentiating and maximizing user experience for specific customer profiles as even the service and network resources are shared.

@article{info3-article-2010-77, abstract = {This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in the Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield a general scoring of a particular behavior. Thus, they are likely to become an important ingredient of the Future Internet. Parameters under evaluation by a reputation system may vary greatly and, particularly, may be chosen to assess the users' satisfaction with (composite) web services. Currently, this satisfaction is usually expressed by QoE, which represents subjective users' opinions. The goal of this paper is to present a novel framework of web services where a reputation system is incorporated for tracking and predicting of users' satisfaction. This approach is a beneficial tool which enables providers to facilitate service adaptation according to users' expectations and maintain QoE at a satisfactory level. Presented reputation systems operate in an environment of composite services that integrate client and server-side. This approach is highly suitable for effective QoE differentiating and maximizing user experience for specific customer profiles as even the service and network resources are shared.}, author = {Ciszkowski, Tomasz and Mazurczyk, Wojciech and Kotulski, Zbigniew and Hoßfeld, Tobias and Fiedler, Markus and Collange, Denis}, journal = {Special Issue of the Springer Telecommunication Systems Journal: Future Internet Services and Architectures - Trends and Visions, print available in 2013}, keywords = {sys:hidden:article}, pages = {283-295}, title = {Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning}, volume = 51, year = 2010 }

%0 Journal Article %1 info3-article-2010-77 %A Ciszkowski, Tomasz %A Mazurczyk, Wojciech %A Kotulski, Zbigniew %A Hoßfeld, Tobias %A Fiedler, Markus %A Collange, Denis %D 2010 %J Special Issue of the Springer Telecommunication Systems Journal: Future Internet Services and Architectures - Trends and Visions, print available in 2013 %P 283-295 %T Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning %V 51 %X This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in the Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield a general scoring of a particular behavior. Thus, they are likely to become an important ingredient of the Future Internet. Parameters under evaluation by a reputation system may vary greatly and, particularly, may be chosen to assess the users' satisfaction with (composite) web services. Currently, this satisfaction is usually expressed by QoE, which represents subjective users' opinions. The goal of this paper is to present a novel framework of web services where a reputation system is incorporated for tracking and predicting of users' satisfaction. This approach is a beneficial tool which enables providers to facilitate service adaptation according to users' expectations and maintain QoE at a satisfactory level. Presented reputation systems operate in an environment of composite services that integrate client and server-side. This approach is highly suitable for effective QoE differentiating and maximizing user experience for specific customer profiles as even the service and network resources are shared.

Inproceedings[ to top ]

Quality of Experience-Related Differential Equations and Provisioning-Delivery Hysteresis. Fiedler, Markus; Hoßfeld, Tobias. In to 21st ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE. Phoenix Seagaia Resort, Miyazaki, Japan, 2010.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
- [ Download ]
Churn of revenue-generating and dissatisfied users has become a major point of concern for service providers and network operators. As services rely on interconnecting networks, service performance and thus user satisfaction depend on network performance. Consequently, it is of outmost importance to understand the relationships between user perception, captured by quantitative Quality of Experience (QoE) parameters, and network performance, described by Quality of Service (QoS) parameters. This paper provides insights into fundamental relationships between QoE and QoS, formulated as partial differential equations describing changes in QoE with respect to specific QoS parameters. A set of illustrating examples is given. Furthermore, the different impacts of provisioning and degree of success or failure of delivery on QoE are discussed, leading to QoE provisioning-delivery hysteresis. This hysteresis provides a striking motivation for employing elastic adaptation mechanisms to available resources instead of suffering from uncontrolled data loss.

@inproceedings{info3-inproceedings-2010-366, abstract = {Churn of revenue-generating and dissatisfied users has become a major point of concern for service providers and network operators. As services rely on interconnecting networks, service performance and thus user satisfaction depend on network performance. Consequently, it is of outmost importance to understand the relationships between user perception, captured by quantitative Quality of Experience (QoE) parameters, and network performance, described by Quality of Service (QoS) parameters. This paper provides insights into fundamental relationships between QoE and QoS, formulated as partial differential equations describing changes in QoE with respect to specific QoS parameters. A set of illustrating examples is given. Furthermore, the different impacts of provisioning and degree of success or failure of delivery on QoE are discussed, leading to QoE provisioning-delivery hysteresis. This hysteresis provides a striking motivation for employing elastic adaptation mechanisms to available resources instead of suffering from uncontrolled data loss.}, address = {Phoenix Seagaia Resort, Miyazaki, Japan}, author = {Fiedler, Markus and Hoßfeld, Tobias}, booktitle = {to 21st ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE}, keywords = {sys:hidden:inproceedings}, month = {03}, title = {Quality of Experience-Related Differential Equations and Provisioning-Delivery Hysteresis}, year = 2010 }

%0 Conference Paper %1 info3-inproceedings-2010-366 %A Fiedler, Markus %A Hoßfeld, Tobias %B to 21st ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE %C Phoenix Seagaia Resort, Miyazaki, Japan %D 2010 %T Quality of Experience-Related Differential Equations and Provisioning-Delivery Hysteresis %X Churn of revenue-generating and dissatisfied users has become a major point of concern for service providers and network operators. As services rely on interconnecting networks, service performance and thus user satisfaction depend on network performance. Consequently, it is of outmost importance to understand the relationships between user perception, captured by quantitative Quality of Experience (QoE) parameters, and network performance, described by Quality of Service (QoS) parameters. This paper provides insights into fundamental relationships between QoE and QoS, formulated as partial differential equations describing changes in QoE with respect to specific QoS parameters. A set of illustrating examples is given. Furthermore, the different impacts of provisioning and degree of success or failure of delivery on QoE are discussed, leading to QoE provisioning-delivery hysteresis. This hysteresis provides a striking motivation for employing elastic adaptation mechanisms to available resources instead of suffering from uncontrolled data loss.
Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning. Ciszkowski, Tomasz; Mazurczyk, Wojciech; Kotulski, Zbigniew; Hoßfeld, Tobias; Fiedler, Markus; Collange, Denis. In Future Internet Architectures: New Trends in Service Architectures (2nd Euro-NF Workshop). Santander, Spain, 2009.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
- [ Download ]
This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield general scoring of a particular behavior. Thus, they are likely to become an important ingredient of Future Internet. Parameters being under evaluation by reputation system may vary greatly and, particularly, may be chosen to assess the users’ satisfaction with (composite) web services. Currently, this satisfaction is usually expressed with QoE, which represents subjective users’ opinions. The goal is to predict users’ satisfaction based on reputation values. This may be beneficial for service providers in terms of checking the fulfillment of SLAs, for retaining QoE on the satisfaction level for other users sharing the same network or service resources, and for providing the users with indications which resource to choose in order to maximize its experience.

@inproceedings{info3-inproceedings-2009-354, abstract = {This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield general scoring of a particular behavior. Thus, they are likely to become an important ingredient of Future Internet. Parameters being under evaluation by reputation system may vary greatly and, particularly, may be chosen to assess the users’ satisfaction with (composite) web services. Currently, this satisfaction is usually expressed with QoE, which represents subjective users’ opinions. The goal is to predict users’ satisfaction based on reputation values. This may be beneficial for service providers in terms of checking the fulfillment of SLAs, for retaining QoE on the satisfaction level for other users sharing the same network or service resources, and for providing the users with indications which resource to choose in order to maximize its experience.}, address = {Santander, Spain}, author = {Ciszkowski, Tomasz and Mazurczyk, Wojciech and Kotulski, Zbigniew and Hoßfeld, Tobias and Fiedler, Markus and Collange, Denis}, booktitle = {Future Internet Architectures: New Trends in Service Architectures (2nd Euro-NF Workshop)}, keywords = {sys:hidden:inproceedings}, month = {06}, title = {Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning}, year = 2009 }

%0 Conference Paper %1 info3-inproceedings-2009-354 %A Ciszkowski, Tomasz %A Mazurczyk, Wojciech %A Kotulski, Zbigniew %A Hoßfeld, Tobias %A Fiedler, Markus %A Collange, Denis %B Future Internet Architectures: New Trends in Service Architectures (2nd Euro-NF Workshop) %C Santander, Spain %D 2009 %T Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning %X This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield general scoring of a particular behavior. Thus, they are likely to become an important ingredient of Future Internet. Parameters being under evaluation by reputation system may vary greatly and, particularly, may be chosen to assess the users’ satisfaction with (composite) web services. Currently, this satisfaction is usually expressed with QoE, which represents subjective users’ opinions. The goal is to predict users’ satisfaction based on reputation values. This may be beneficial for service providers in terms of checking the fulfillment of SLAs, for retaining QoE on the satisfaction level for other users sharing the same network or service resources, and for providing the users with indications which resource to choose in order to maximize its experience.