Efficient overlay multicast protocol using unicast routing infonnation in mobile ad hoc networks

Overlay multicast protocols in mobile ad hoc networks (MANET) have advantages that are low overhead and robustness in dynamic network topology by using the unicast routing protocol between group members. However, overlay data paths in overlay multicast can remain static even though the underlying physical topology is changing. Overlay multicast may lead to sub-optimal overlay data paths, since the communicating group members are not aware of the underlying physical topology. Therefore, overlay multicast protocols requires periodic control messages for the overlay data path management in dynamic environment. In this paper, we propose an efficient overlay multicast protocol (EOMP) using unicast routing information. Multicast state information of each group member in EOMP is created by its unicast routing table. Therefore, multicast data packets between group members are delivered through the overall optimal paths in physical networks. Meanwhile, the overlay data path in EOMP can be managed without periodic control messages in the dynamic environment. Finally, we evaluate EOMP performance with other multicast protocols proposed for ad hoc networks. Simulations show enhanced results of proposed protocols.