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

Speech quality assessment in communication networks with varying delay

This thesis discusses the assessment of speech quality transmitted through telecommunication networks. The aim is to produce a model able to estimate the overall listening quality of speech signals as measured by subjective tests. Objective models for speech quality assessment have been developed for the last twenty years and the most widely adopted is PESO. the currently in-force ITU-T Recommendation P .862. PESQ shows inaccuracy when assessing signals recorded from modern t elecommunication networks that exhibit highly va riable delay such as Voice over lP. This issue is investigated and addressed in this thesis. Objective models for qua lity assessment are generally designed to predict subjective tests, on which they are trained and verified. The behaviour of the model and its accu racy are therefore high ly dependent on the relia bility and the resolution of the subjective t ests. Some aspects of subjective test methodologies are disc ussed in this thes is. The most reliable speech quality. assessment models are perceptual algorithms that compare shortterm representations of the input and the o utput signals of the system under test. This type of model relies on an accurate estimation of the time re lat io nship between the two signa ls. This t hesis shows that the inaccuracy of PESQ for quality assessment of modern telecommunication networks is due to its t ime alignment. Previous time alignment methods for objective models are not suited to frequent delay variation. A new t ime-alignment technique based on correlation of frequency domain representations and sho rtterm delay histograms is presented, allowing robust alignment in t he presence of highly varying delay. A new objective model built from the integration of the proposed time-a lignment with PESQ was verified on a very large number of subjective tests. Results show signifi cant improvements over PESQ in situations presenting frequent delay va riations while keeping the similar level of accuracy in the cases of occasional variations.EThOS - Electronic Theses Online ServiceGBUnited Kingdo