A multicast protocol avoiding unnecessary data forwarding with source distinction in mobile ad hoc networks

In this paper, we improve On-Demand Multicast Routing Protocol (ODMRP), which is a multicast routing protocol for Mobile Ad hoc Network (MANET), and propose a new protocol decreasing the number of data forwarding without deteriorating communication reliability. The proposed protocol avoids unnecessary data forwarding by distinguishing each multicast source at every Forwarding Group (FG) Node used in ODMRP. Moreover, the proposed protocol utilizes Support Group (SG), which also distinguishes each multicast source, in order to retain substitute routes without any redundant data forwarding. Therefore, the proposed protocol can avoid deteriorating communication reliability. We evaluate the performance of ODMRP, ODMRP with SG, and the proposed protocol, and we show that the proposed protocol can decrease the number of data forwarding compared with the conventional protocols. We also show that the proposed protocol can restrain the deterioration of packet delivery ratio within allowable range except the case where the number of multicast sources and receivers is extremely large. Furthermore, we show that the proposed protocol can mitigate the deterioration of packet delivery ratio caused by traffic congestion in the case where the number of multicast sources is large.