An Overlay Multicast Protocol for Multimedia Applications in Mobile Ad Hoc Networks

Overlay multicast has gained much attention in recent years as an alternative method to network layer multicast, especially for mobile ad hoc networks(MANETs). In this paper, we propose a new overlay multicast protocol to achieve simplicity of deployment, rapid adaptation of overlay structure when nodes move, and reduced delay. In our algorithm, to join or leave a multicast group, it is only sufficient for a member node to inform its first upstream member node. This updates the tree structure more rapidly when nodes move. In addition, join and leave delays are reduced and this makes the protocol suitable for multimedia multicasting in MANETs. Simulation results compared to that of ODMRP and ODOMP show that when the number of member nodes increases, our protocol outperforms ODOMP and when speed of nodes is high, it outperforms both ODOMP and ODMRP in terms of delivery ratio.