Accurate and fast multi-rate multicast scheme in wireless networks

Exploiting multi-user diversity (MUD) for multicast consists in choosing the data rate(s) utilized to serve a number of users who have different channel qualities. Some of the proposed multicast schemes aim to maximize the throughput (e.g. EMTH), while others seek to reduce the transmission time (e.g. EMTT). Actually, it is well known that the process of computing the accurate MUD multicast throughput has a complexity that increases if the number of users rises. Generally, the metrics that maximize the throughput give an approximation of the achievable throughput. In this paper, we suggest an accurate, distributed, low-complexity and stateless multicast scheme that exploits the MUD. This scheme is called MOST. It selects the transmission strategy, i.e. the utilized set of data rates which maximizes the multicast throughput. MOST is computed using a very fast special way. It finds the best transmission strategy without any need to check all the transmission possibilities, or data rate combinations. This study highlights the complexity of the multicast scheme that verifies all the transmission strategies and describes the design and the performance of the new one, MOST.