An efficient multicast routing protocol in wireless mobile networks

Providing multicast service to mobile hosts in wireless mobile networking e nvironments is difficult due to frequent changes of mobile host location an d group membership. If a conventional multicast routing protocol is used in wireless mobile networks, several problems may be experienced since existi ng multicast routing protocols assume static hosts when they construct the multicast delivery tree. To overcome the problems, several multicast routin g protocols for mobile hosts have been proposed. Although the protocols sol ve several problems inherent in multicast routing proposals for static host s, they still have problems such as non-optimal delivery path, datagram dup lication, overheads resulting from frequent reconstruction of a multicast t ree, etc. In this paper, we summarize these problems of multicast routing p rotocols and propose an efficient multicast routing protocol based on IEFT mobile IP in wireless mobile networks. The proposed protocol introduces a m ulticast agent, where a mobile host receives a tunneled multicast datagram from a multicast agent located in a network close to it or directly from th e multicast router in the current network. While receiving a tunneled multi cast datagram from a remote multicast agent, the local multicast agent may start multicast join process, which makes the multicast delivery route opti mal. The proposed protocol reduces data delivery path length and decreases the amount of duplicate copies of multicast datagrams. We examined and comp ared the performance of the proposed protocol and existing protocols by sim ulation under various environments and we got an improved performance over the existing proposals.