Application layer multicast (ALM) tree constructing apparatus, ALM tree constructing method, program, and integrated circuit

摘要

The ALM tree constructing apparatus includes a metric measuring unit for measuring an upload link bandwidth for each of terminals; and a node allocating unit allocating, to each of the terminals, at least one of (i) an upper terminal and (ii) one or more lower terminals. A first branch allocating unit allocates at least a part of the upload link bandwidth which is assigned to each of the terminals that has the lower terminal allocated, so that the part of upload link bandwidth acts as a logical first branch for distributing the data stream; and a second branch allocating unit allocates a remaining bandwidth, unused as the logical first branch, to a terminal provided in a hierarchy level below the terminal having the remaining bandwidth, so that the remaining bandwidth acts as a logical second branch for distributing reference data regarding the data stream.