Quality of Experience of WebRTC based video communication
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Online video applications are growing in popularity and using anincreasing share of the consumer Internet traffic. Web Real-Time Communication (WebRTC) is a new technology which allows browser-to-browsercommunications without any software downloads or user registration.The focus of this report is the Quality of Experience (QoE) in the contextof WebRTC. We have created a fully controllable testing environment, a testbed,where we can manipulate a network to perform under various conditionsby altering the parameters packet loss rates, Mean Loss Burst Size(MLBS), delay, jitter, Central Processing Unit (CPU), and bandwidth. Atestbed is of importance for testing of QoE services in general, and alsofor application developers because they can analyze their application sbehavior in altered networks which can simulate real-world use. We have used the WebRTC application appear.in for several differentexperiments where we altered the network conditions. We have col-lected both connection statistics and the subjective feedback from eachparticipant. Firstly, we conducted a pilot study consisting of two-party conversa-tions of 12 participants, where our main focus was on packet loss andMLBS. After that, we conducted three-party conversations where wetested packet loss, MLBS, delay, jitter, and CPU. We found in our experiments that the perceived quality of a specificpacket loss rate depends also on the MLBS. Higher MLBS seems to resultin an overall worse user experience, especially impacting the audio qualityof the conversation. We also found that delay (<1 second) does notnecessarily leads to a worse user experience, while jitter quickly impactsboth audio and video quality. Finally, it seems that the CPU limitationsseem to affect only the user with the reduced CPU-usage. The experiments show that the testbed is working as specified, andcan be used for more extensive research in the future. Keywords - WebRTC, Quality of Experience, appear.in, testbed, pilotstudy, Mean Loss Burst Size.