Institute for Telecommunication Sciences / Research / Quality of Experience / Quality of Experience

Quality of Experience

The ITS Audio Quality Research and Video Quality Research programs develop and evaluate technically advanced tools to support the assessment of user experience for both audio and video transmissions.

Wireless devices and services continue to proliferate and compete for a fixed amount of usable radio spectrum, as dictated by the laws of physics. This means that spectrum must be shared and interference must be tolerated to the maximal extent. But how do we best define those limits?

The litmus test for determining whether any spectrum dependent system is useful and effective is the experience of the end user. Engineers use metrics such as bit error rate or compression ratio to evaluate system performance and make adjustments that optimize the trade-off between bandwidth and quality. End users, on the other hand, judge a system in terms of the perceived quality of experience (QoE)—for example, the visibility of targets on a radar display, the intelligibility of an audio stream, or the number of individually identifiable objects in a video stream.

The most relevant definitions are related to users’ experiences—sharing and interference can be tolerated up to the level where they start to degrade users’ experiences. Tools that can quickly and reliably track audio quality and video quality are one meaningful way to identify successful and unsuccessful spectrum sharing. Objective measures that can provide useful indications of the quality the user experiences independent of the underlying transmission medium provide critical feedback for system design and provisioning so that users’ expectations can be met in the most spectrally efficient way.