Patent ID: 7969952

Claim:
A method of implementing a multicast routing system in a mobile ad-hoc network environment, the method comprising: transmitting control packets for data transmission from a source node to object nodes in accordance with a predetermined method when data to be transmitted from the source node to the object nodes exists; forming, in a tree structure, information concerning nodes on paths through which the control packets are transmitted; and causing the source node to transmit the data to the object nodes using the formed tree structure; wherein the causing the source node to transmit the data to the object nodes comprises, when the data transmitted to the object notes is lost: causing a child node to transmit to a first parent node, which is a parent of the child node, identification information for identifying the lost data; and if the first parent node has the data packet corresponding to the identification information, causing the first parent node to transmit a data packet corresponding to the identification information to the child node; and if the first parent node does not have the data packet corresponding to the identification information, the first parent node to transmit the identification information to a second parent node, which is a parent of the first parent node, so as to request for the data packet corresponding to the identification information; wherein the forming of the information concerning the nodes comprises: causing the object nodes to transmit packets indicating the existence of the object nodes; causing the nodes existing on the paths, through which the control packets are transmitted between the source node and the object nodes, to store information concerning child nodes and parent nodes using the packets transmitted from the object nodes; and forming the tree structure from the stored information.