University of Peloponnese
In multi-rate multicasting, different users (receivers) within the same multicast group can receive service at different rates, depending on the user requirements and the network congestion level. Compared to unirate multicasting, this provides more flexibility to the user, and allows more efficient usage of the network resources. In this paper, the authors address the rate control problem for multi-rate multicast sessions, with the objective of maximizing the total receiver utility. This aggregate utility maximization problem not only takes into account the heterogeneity in user requirements, but also provides a unified framework for diverse fairness objectives. They propose an algorithm for this problem and show, through analysis and simulation that it converges to the optimal rates.