92 research outputs found
Crowdsourced network measurements: Benefits and best practices
Network measurements are of high importance both for the operation of networks and for the design and evaluation of new management mechanisms. Therefore, several approaches exist for running network measurements, ranging from analyzing live traffic traces from campus or Internet Service Provider (ISP) networks to performing active measurements on distributed testbeds, e.g., PlanetLab, or involving volunteers. However, each method falls short, offering only a partial view of the network. For instance, the scope of passive traffic traces is limited to an ISP’s network and customers’ habits, whereas active measurements might be biased by the population or node location involved. To complement these techniques, we propose to use (commercial) crowdsourcing platforms for network measurements. They permit a controllable, diverse and realistic view of the Internet and provide better control than do measurements with voluntary participants. In this study, we compare crowdsourcing with traditional measurement techniques, describe possible pitfalls and limitations, and present best practices to overcome these issues. The contribution of this paper is a guideline for researchers to understand when and how to exploit crowdsourcing for network measurements
Describing Subjective Experiment Consistency by -Value P-P Plot
There are phenomena that cannot be measured without subjective testing.
However, subjective testing is a complex issue with many influencing factors.
These interplay to yield either precise or incorrect results. Researchers
require a tool to classify results of subjective experiment as either
consistent or inconsistent. This is necessary in order to decide whether to
treat the gathered scores as quality ground truth data. Knowing if subjective
scores can be trusted is key to drawing valid conclusions and building
functional tools based on those scores (e.g., algorithms assessing the
perceived quality of multimedia materials). We provide a tool to classify
subjective experiment (and all its results) as either consistent or
inconsistent. Additionally, the tool identifies stimuli having irregular score
distribution. The approach is based on treating subjective scores as a random
variable coming from the discrete Generalized Score Distribution (GSD). The
GSD, in combination with a bootstrapped G-test of goodness-of-fit, allows to
construct -value P-P plot that visualizes experiment's consistency. The tool
safeguards researchers from using inconsistent subjective data. In this way, it
makes sure that conclusions they draw and tools they build are more precise and
trustworthy. The proposed approach works in line with expectations drawn solely
on experiment design descriptions of 21 real-life multimedia quality subjective
experiments.Comment: 11 pages, 3 figures. Accepted to 28th ACM International Conference on
Multimedia (MM '20). For associated data sets, source codes and
documentation, see https://github.com/Qub3k/subjective-exp-consistency-chec
Quality of experience in telemeetings and videoconferencing: a comprehensive survey
Telemeetings such as audiovisual conferences or virtual meetings play an increasingly important role in our professional and private lives. For that reason, system developers and service providers will strive for an optimal experience for the user, while at the same time optimizing technical and financial resources. This leads to the discipline of Quality of Experience (QoE), an active field originating from the telecommunication and multimedia engineering domains, that strives for understanding, measuring, and designing the quality experience with multimedia technology. This paper provides the reader with an entry point to the large and still growing field of QoE of telemeetings, by taking a holistic perspective, considering both technical and non-technical aspects, and by focusing on current and near-future services. Addressing both researchers and practitioners, the paper first provides a comprehensive survey of factors and processes that contribute to the QoE of telemeetings, followed by an overview of relevant state-of-the-art methods for QoE assessment. To embed this knowledge into recent technology developments, the paper continues with an overview of current trends, focusing on the field of eXtended Reality (XR) applications for communication purposes. Given the complexity of telemeeting QoE and the current trends, new challenges for a QoE assessment of telemeetings are identified. To overcome these challenges, the paper presents a novel Profile Template for characterizing telemeetings from the holistic perspective endorsed in this paper
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