An adaptive multirate congestion control protocol for multicast communications

The field of multicast congestion control has been dominated by two kind of approaches: single-rate and multirate transmission; but neither of these alternatives is completely satisfactory, as they are either too much complex or do not adapt properly to heterogeneous environments. More recently there have arisen some new proposals advocating the use of hybrid models that retain the single-layer simplicity while aiming to have the same scalability as the multi-layer schemes. However, no current solution takes into account the real bandwidth requirements of the receivers. In this article we propose a new hybrid multicast congestion control algorithm that accounts for the expected rate of each receiver to allocate the transmission rates of each layer. Given a number of available layers, our protocol is able to compute the transmission rates that maximize the network utilization of all receivers. We also show experimentally that our framework for congestion control is able to compete fairly with TCP, thus making it a good candidate to be deployed in the current Internet.