Asymmetric delay in video-mediated group discussions

Abstract

Delay has been found as one of the most crucial factors determining the Quality of Experience (QoE) in synchronous video-mediated communication. The effect has been extensively studied for dyadic conversations and recently the study of small group communications has become the focus of the research community. Contrary to dyads, in which the delay is symmetrically perceived, this is not the case for groups. Due to the heterogeneous structure of the internet asymmetric delays between participants are likely to occur.We conducted a trial with video-mediated group discussions with five participants in symmetric and asymmetric delay conditions. In this paper we focus on the asymmetric conditions, in which only one participant has an added delay. Previous research showed that interaction and context are essential factors in the QoE of participants. Therefore, we perform an analysis of our data towards these factors and compare our data between the asymmetric and the symmetric delay conditions. We discuss the differences in perception of delay reported from multi-party to dyadic video-conferencing.Our data shows that already one person with a high delay, affects the experience of the whole group as strong as the person with delay. This disruption is perceived more intensely by active participants rather than non-active ones-regardless of whether they have the delay or not. Compared to dyadic situations the group scenario shows a less intense perception of delay.

Towards context-aware interactive Quality of Experience evaluation for audiovisual multiparty conferencing

“…It is known that the interactivity (e.g. amount speaker changes) aggravates the effect of delay [19][20] [21]. There are also indications that in cases of double talk higher audio quality improves the experience [22].…”

The Influence of Interactivity Patterns on the Quality of Experience in Multi-party Video-mediated Conversations under Symmetric Delay Conditions

“…We already reported about the investigation of asymmetric delay conditions and general differences between asymmetric, symmetric and dyadic setups [12]. In this paper we make a more fine-grained analysis user interactivity taking into account role-theory as well.…”

Video QoE killer and performance statistics in WebRTC-based video communication

“…This testbed was subsequently used in a number of studies. In [5], the impact of asymmetric delay on QoE was investigated for multi-party telemeetings. The study findings confirmed the assumed negative impact of asymmetric delay: if a delay of more than 500 ms is introduced for only one participant, this has a severe negative impact on the QoE of the whole group.…”

“…The messages of sender and receiver (audio and video input) need to be recorded, prepared and encoded for transmission, transmitted over a network, decoded by the receiving device and finally presented to the other party [5]. During each of these steps, delay and additional technical artefacts that may impact the produced and experienced audio and video quality, as well as the synchronisation between both modalities [6] may be introduced.…”