Mcore: A simple structure for effective overlay multicast on mobile ad hoc networks

Overlay multicast protocol constructs a virtual mesh spanning all member nodes of a multicast group and employs standard unicast routing to fulfill multicast functionality on application layer. The advantages of this approach are simplicity and flexibility. However, efficiency and stability are the issues that must be addressed as the size of the multicast group grows in the mobile ad hoc networks (MANETs). In this paper, we propose an effective structure for overlay multicast to solve these problems in MANETs. Instead of using a spanning tree on the virtual mesh, we adopt a simple structure called MCore for multicast. An MCore is a path that minimizes the sum of the distances of all vertices to the path plus the length of the path. The MCore is more stable and easier to maintain than the spanning tree in MANETs. The simulation results show that our approach handles the flexibility and mobility issues in overlay multicast protocols effectively for large multicast group size.