Analytical Study of QoS-Oriented Multicast in Wireless Networks

Multicast is a very popular bandwidth-conserving technology exploited in many multimedia applications. However, existing standards of high rate wireless networks provide no error recovery mechanism (ARQ) for multicast traffic. ARQ absence in wireless networks unreliable by their nature leads to frequent packet losses, which is inappropriate for most of multimedia applications. In this paper, we study new reliable multicast mechanism proposed recently to support multimedia QoS (packet loss ratio, latency, and throughput) with various wireless technologies. This mechanism is based on the concept of multiple ACK-leaders, that is, multicast recipients responsible for acknowledging data packets. We develop analytical models of the mechanism with various leader selection schemes and use the models to study the schemes efficiency and to optimize them. Numerical results show that the novel multicast mechanism with multiple ACK-leaders can be easily tuned to meet specific QoS requirements of multimedia or any other multicast applications.