On-line Optimal Wireless Multicast

The paper is directed towards designing bandwidth efficient strategies for MAC layer multicast. Bandwidth efficiency of wireless multicast can be improved substantially by exploiting the fact that several receivers can be reached at the MAC layer by a single transmission. However, this feature can be effectively exploited only by resolving several decision problems and protocol challenges. The first issue is to determine when a sender should transmit in order to maximize its throughput while maintaining the system stability. We provide an on-line strategy and prove using the large deviation theory that it solves the decision problem optimally without requiring any system statistics. The protocol challenge is to design a message exchange protocol to acquire the information necessary for execution of the optimal transmission strategy. We provide a MAC protocols for this purpose. The performance evaluations demonstrate that the optimal strategy significantly outperforms the existing approaches in multi-hop multicast wireless networks.