CAMT: Core assisted multicast tree for ad hoc networks

Generally, the multicast routing protocols for mobile ad hoc networks (MANETs) build and maintain a group shared (tree or mesh-based) multicast delivery structure, which results in inefficient propagation of multicast traffic. In this article, a source tree based multicast routing protocol CAMT is proposed. CAMT employs only a fraction of nodes (core nodes) to disseminate their own and their neighbors´ multicast interests to the network, while assuring the representation of all multicast receivers in these messages. As a result, only a small number of multicast group interest messages are generated. Moreover, CAMT benefits from the multipoint relay (MPR) optimizations to minimize retransmissions of these messages. Based on the information learnt through these messages, any multicast sender can generate a shortest path tree (rooted at itself), spanning across all core nodes interested in a particular multicast group. Simulation results indicate that the proposed protocol performs well under different network conditions.