MCDS Based Multicasting in Mobile Adhoc Networks

Multicasting in resource constrained MANETs imposes a severe restriction on the message overhead for construction and maintenance of the multicast distribution tree. Algorithms based on minimum spanning trees (MST) or Steiner trees require reconstruction of the tree when members join or leave a multicast group in addition to change in network topology. In the present paper, multicasting based on MCDS with local repair is presented. The proposed MCDS algorithm tries to optimize the number of messages required for construction and maintenance of the multicast backbone. It is observed that when a node joins or leaves the multicast group, the time taken for repair with local route discovery is almost constant and is independent of multicast group size. Moreover, there is only a modest increase in the CDS size. The results are similar when a node that is not a member of the multicast group but forms a part of the MCDS moves away resulting in a change of the network topology.