Design and evaluation of a new overlay multicast protocol for ad hoc networks

Abstract

In this paper we present a new application layer multicast, or an overlay multicast, protocol for medium to large scale mobile ad hoc networks. In overlay multicast protocols, only multicast member nodes maintain multicast routing state, which make multicast routing less complicated and more scalable than network layer multicast protocols. Using the concept of sectors, the proposed protocol, called SSOM, builds a hierarchical multicast tree of two levels: high-level source-based trees for sources and low-level shared trees for receivers. The proposed protocol handles both group dynamics (member joins and leaves) and network dynamics (node movements) efficiently. Therefore, its overhead to create and maintain multicast trees is not high and the packet delay over multicast trees is sub-optimal. The proposed protocol is compared qualitatively with other overlay multicast protocols and its performance is evaluated through simulation.