Sigmoid function-based layered multicast with intra-layer rate adjustment
基于sigmoid函数的层内速率调节的分层组播

Instead of re-layering and re-allocating sending rates, multi-rate multicast with intra-layer rate adjustment distributes layer's sending rate into fixed intervals and adjusts the actual layer's sending rate within its interval according to the selected delegate of the layer group. The synthesized probability formula based on sigmoid function was proposed for delegate selection. Two factors determine whether the current feedback receiver can be selected or not. One is the relative difference between feedback rate and current layer sending rate, the other is the approximate rate distribution of receivers within this layer group. Simulation results show that SFBLM can meet most of receivers' demand within a layer group, and it is TCP friendly.