Patent ID: 7957301

Claim:
A method for multicast communication in a network having plural nodes according to the ZigBee network specification, said method comprising: creating a multicast group that includes a subset of the plural nodes and excludes at least one non-member node in the plural nodes, said multicast group having a multicast address, wherein the creating further comprises: sending a join request (JREQ) message from a joining node seeking to join the multicast group to a receiving node; and sending a join reply (JREP) message from the receiving node to the joining node, the JREP message including a path cost to a node in the multicast group from the joining node; forwarding an updated JREQ message from the receiving node to another node if the receiving node is not a member of the multicast group, the updated JREQ message including a sum of a link cost included in the JREQ message and a link cost of a communication link between the joining node and the receiving node; receiving another JREP message from the another node, the another JREP message including a path cost to a node in the multicast group from the receiving node; and setting the path cost in the JREP to be sent to the joining node by the receiving node to be a sum of the path cost included in the another JREP message and a link cost between the joining node and the receiving node; transmitting a multicast message including the multicast address; and receiving the multicast message at each node in the multicast group.