Patent ID: 7403492

Claim:
A method for supporting multicast in a multihop wireless network, the method comprising: establishing certain nodes in the network as core source nodes, wherein the establishing step comprises: determining whether a node should be a core source node for a multicast group, based on criteria comprising a number of activated core sources in the network, a multicast core source number threshold, a distance to a closest activated core source, a number of hop counts from the node to one of the activated core sources, an address of the node, and an address of the closest activated core source; engaging in a multicast tree discovery or refreshing process by operating at least one of the core source nodes to broadcast a route request (RREQ) message; and building the multicast tree or refreshing the multicast tree based on the RREQ message, and at least one route reply (RREP) message received by the at least one core source node from another node in response to the RREQ message.