Stable On-demand Overlay Multicast in Mobile Ad Hoc Networks

Reactive overlay multicast approaches e.g. ODOMP, for mobile ad hoc networks (MANETs) have the advantages of low topology maintenance overhead and high stability. In this paper, we propose a reactive overlay multicasting approach based on delayed forwarding mechanism. This approach consists two parts: overlay multicasting and one-hop clustering. A reactive source rooted overlay multicast tree which only composes of source and one-hop cluster leaders will be created in case of source has to send data packets. While the one-hop clustering is a proactive mechanism and is performed throughout the multicast session. These seem to be incompatible. However, we propose a mechanism to syncretize them together and make the protocol achieves high performance. To enhance stability, the overlay tree creation follows the stability of each cluster leader. Data packets are transmitted via IP-in-IP tunnels in the overlay tree. An one-hop cluster leader takes charge of broadcasting data packets to its cluster members by utilizing capability of the wireless medium as well as delivering date packets to downstream cluster leaders