Main research findings

Empirical Analysis of QoS and QoE in Mobile Broadband Networks, or alternatively, Why is my Internet so slow? And why does my video keep buffering?

Mobile broadband (MBB) networks are a key component of modern communication infrastructures and they underpin vital operations in society. As MBB network performance has significant consequences for a large number of stakeholders, measurements are necessary for continuous evaluation and benchmarking.

In this thesis, we present an empirical study of MBB network performance from two aspects: Quality of Service (QoS) as experienced by the end-users of speedtests, and Quality of Experience (QoE) as experienced by the end-users of adaptive video streaming applications. Our goal is to identify the influencing factors on selected QoS and QoE metrics.

Our study of operational networks (``measurements in the wild'') shows that there are clear differences in network performance depending on underlying application, transport, network, and physical layer parameters, as well as spatio-temporal factors and measurement configurations. We find that MBB networks vary in terms of their performance stability over time, and their ability to support popular applications such as video streaming. We identify the most prominent influencing factors for selected QoS and QoE metrics, and quantify their effects where possible. We provide the research community with multiple open-source frameworks for continued empirical analysis of MBB networks, along with open datasets from various measurement studies.

The work has been conducted at SimulaMet and the University of Oslo. 

Adjudication committee

• Professor Saverio Mascolo, Dipartimento di Ingegneria Elettrica e dell'Informazione (DEI), Politecnico di Bari, Italy
• Associate Professor Laura Toni, Institute of Communications and Connected Systems, University College London, United Kingdom
• Professor Tor Skeie, University of Oslo, Department of informatics Norway

Supervisors

• Senior Research Scientist Özgü Alay, Department of Informatics, UiO / SimulaMet
• Professor Carsten Griwodz, Department of Informatics, UiO / SimulaMet 

Chair of defense

• Associate Professor Petter Nielsen, University of Oslo, Department of informatics Norway