An approach to correlation of QoE/QoS metrics over IPTV using a Diffserv Network

Network operators increasingly focus their attention on fulfilling the expectations of quality of experience (QoE) for the delivery of video services to their users. Therefore, it is important to analyze the correlation between objective and subjective QoE metrics such as PSNR (Peak Signal Noise Ratio), SSIM (Structural Similarity Index Metric), VQM (Video Quality Metric), and MOS (Mean Opinion Score), and thus to obtain high quality levels of video delivery to the viewer, using schemes of QoS (Quality of Service) through strategies based on active queue management (AQM) to control network congestion like WRED (Weighted Random Early Detection). In this paper we propose an equation to estimate the MOS through correlation of objective QoE and QoS parameters, which is generated by multiple regression statistical analysis. We also present a testbed (operational simulation environment) set with Besteffort and Diffserv networks performed in NS-2, which allows us to compare both objective and subjective quality metrics for different rates of packet loss over a network link and varying encoding parameters like bitrate and GOP (Group of Pictures) length. The results show a high correlation between metrics for video sequences with low and high motion and a better quality of video delivered over QoS network, controlling congestion and reducing loss frames over video delivered. KeywordsObjective Metrics, Subjective Metrics, IPTV, QoS,