Fig. 3From: QoE optimization of video multicast with heterogeneous channels and playback requirementsOutage probability approximation. A comparison between Q l (δ) (solid blue line) and [1−P(S l ,N l ,δ)] (dashed red line) for the different layers of a three-layer video stream. δ 1=0.526,δ 1=0.572,δ 1=0.607 for outage probability constraints similar to those expressed in Section 5 Back to article page