Abstract: A window based multi-rate multicast congestion control(WMCC) algorithm is proposed. The sender of a multicast session changes the rate of each layer dynamically and adaptively according to the feedbacks from receivers. Each receiver maintains a congestion window on the base layer and adjusts it based on the binomial algorithm, and from the congestion window an expected rate is calculated. The receiver subscribes to appropriate layers based on its expected rate, thus obtaining a corresponding throughput. Simulations indicate that WMCC is effective in providing a multi-rate multicast congestion control, and shows good TCP-friendliness, smoothness and responsiveness.

Key words: multicast, multi-rate, congestion control