Effectiveness of overlay multicasting in mobile ad-hoc network

This paper investigates the effectiveness of the application level multicasting, named overlay multicasting, with respect to the network layer one in Mobile Ad Hoc Networks (MANET). With respect to network layer multicasting, in overlay multicasting only the mobile nodes participating to the multicast group exploit the multicast routing at application level, while the other nodes of the MANET simply perform unicast IP routing. This constraint in the possibility of use multicast routing in all nodes leads to a loss of efficiency in the bandwidth usage that we aims to discuss in this paper. The parameter used for the comparison is the cost of the multicast distribution tree, which is built by means of Steiner based algorithms. We measure this parameter by means of an exhaustive simulation campaign, analysing the performance dependence versus different parameters: device coverage range, number of MANET nodes, multicast group size and mobility model.