A Model-Based Approach to Understanding and Improving Video Conferencing Quality of Experience
Author(s)
He, Jia
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Abstract
In recent years, influenced by trends towards remote work, video conferencing has be-
come an important tool for business, education, and personal communications. Network
operators, business users, and researchers have a renewed interest in how video conferenc-
ing applications (VCAs) work, and improving the user quality of experience (QoE).
We look at the question of VCAs and QoE from two perspectives; networking and
interactivity. On the networking side, we build an understanding of VCA architecture by
developing functional models of the VCA client and selective forwarding unit (SFU), the
central server that forwards media between users and enables efficient scaling of video
conferences. We developed these models using an active measurement campaign to study
aspects of the VCA and SFU such as the congestion control and user interface interaction.
On the interactivity side, we designed a model of how a VCA client takes turns and
interacts with others. Combined with objective metrics we define for interactivity, we
can experiment with network latency and understand the negative effect it has on these
metrics and hence the QoE. This model-based methodology expands upon the user study
method commonly employed by literature in this area. By implementing appropriately pa-
rameterized client models within a simulator program, we show how latency impacts the
interactivity metrics, such as the overlap rate or the proportion of useful conversation time.
Lastly, we investigate how to improve interactivity in the presence of network latency.
We use the client model methodology to evaluate systems suitable for deployment on the
VCA SFU that can address the issue of network latency by improving the interactivity
metrics. In particular, we design and evaluate two systems; one that adjusts the latency of
the forwarded media, and one that informs clients of latency via notifications, and show that
these methods can improve interactivity across a variety of video conferencing scenarios.
We hope that the models and results from this research will be useful for improving
user QoE for video conferencing, an important and modern communications tool.
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Date
2025-12
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Text
Resource Subtype
Dissertation (PhD)