MAC Layer Multicast in Wireless Multihop Networks

Many applications in wireless ad-hoc networks require multicast communication. In order to provide efficient multicast, various multicast routing protocols have been designed in recent years to facilitate formation of routes between multicast senders and receivers. There has also been some work to develop a suitable MAC protocol to improve efficiency of multicast communication. In this work we explore some approaches for reliable multicast at the MAC layer. We develop a multicast extension of IEEE 802.11 protocol and evaluate its performance. We have implemented our protocol in the popular ns-2 simulator and have performed experiments with multicast routing protocol. Our approach demonstrates superior performance in terms of packet delivery fraction as well as delay compared to the IEEE 802.11 protocol