An enhanced reliable multicast protocol for wireless environments

This paper presents a performance study, using both analytical modeling and simulation techniques, of a new end-to-end reliable multicast protocol for use in environments with wireless access. The proposed protocol, known as the reliable mobile multicast protocol (RM2), divides a multicast tree into sub-trees where subcasting is applied within these relatively smaller regions using a hierarchical tree of retransmission servers. More importantly, RM2 uses a dynamic retransmission strategy to switch between multicast and unicast retransmission modes according to the amount of extra load generated in the network as well as at the wireless interfaces by packet retransmissions. It is shown through both analytical modeling and simulation that RM2´s dynamic adaptation is not only important but also necessary when considering mobile wireless access