There are increasing interest and big challenge in

designing a scalable and robust multicast routing protocol in

a mobile ad hoc network (MANET) due to the difficulty in

group membership management, multicast packet forwarding

and the maintenance of multicast structure over the dynamic

network topology for a large group size or network size. In

this paper, we propose a novel Robust and Scalable Geographic

Multicast Protocol (RSGM). Several virtual architectures are used

in the protocol without need of maintaining state information for

more robust and scalable membership management and packet

forwarding in the presence of high network dynamics due to

unstable wireless channels and node movements.