Reliable Multicast Error Recovery Algorithm in Ad-Hoc Networks

Mobile ad hoc network is an autonomous system of mobile nodes characterized by wireless links. The major challenge in ad hoc networks lies in adapting multicast communication to several environments, where mobility is unlimited and failures are frequent. Reliable multicast delivery requires a multicast message to be received by all mobile nodes in the communication group. The recovery mechanism requires feedback messages from each one of the receivers. In the tree-based recovery protocols, a group of nodes into recovery regions designate a forwarding node per region for retransmitting lost messages. In this study, local error recovery algorithm is applied within these relatively smaller regions, where the repaired packets are retransmitted only to the requested receivers in the local group. These receivers create a sub group from the local group which itself is a subgroup of the global multicast group. By applying local error recovery algorithm, the number of duplicated packets, due to packets retransmission, decreases which lead to improving the system performance. Simulation results demonstrate the scalability of the proposed algorithm in comparison to Source Tree Reliable Multicast (STRM) protocol. The algorithm achieved up to 2.33% improvement on the percentage of duplicated packets in stable mobility speed without incurring any further communication or intense computation overhead.