QoE Aware Player using Playing Rate Adaptation for Progressive Download Services over Broadcast Networks

In this paper, a QoE (quality of experience) aware player is introduced that changes the temporal characteristics of streaming according to subjective parameters to increase the QoE. With the proposed player, two contributions are provided. First, the capability of rate adaptation methods is further enhanced by the playing rate adaptation where playing some video segments in negligible reduced rate is argued to provide better QoE than the ones degraded by start-stop failures that otherwise would be possible. Second, the temporal distribution of the start-stop failures can be modelled according to the user preference so that user‘s expectancy is better satisfied. Currently, start-stop failure has the dominant effect on QoE since the other types of streaming errors, such as color distortions, can be significantly avoided with the protection of the streaming channels against packet losses, e.g. using Forward Error Correction. With the channel protection, the overall network errors are projected onto behaviors of the buffering model. The buffering should be described by welldefined states and expected behaviors in that expected behaviors, from the user expectation point of view, are better than the random ones. As a case study, the streaming service is considered to be progressive downloading over 3GPP’s MBMS (multimedia broadcast multicast service) as the underlying network. In order to prove the accuracy of the proposed model, objective and subjective study using DSIS (double stimulus impairment scale) and DSCS (double stimulus comparison scale) are provided. The results show that QoE aware player increases the user satisfaction from the service. Key-Words: QoE, Streaming, Playing Rate Adaptation, MBMS, Progressive Download