Tree-type network system, node device, broadcast system, broadcast method, and the like

Abstract

A tree type network system including an information delivery device, a plurality of node devices, and an administration, wherein the node devices are connected in a tree-like shape via a communication route while placing the information delivery device in an uppermost level and forming a plurality of hierarchy levels, and the delivery information is sequentially transferred from the node device in an upper hierarchy level to the node devices in lower hierarchy levels, wherein the administration device includes: a device for acquiring attribute information of a node device, which transmits participation request information, and determines device information on the basis of the attribute information thus acquired upon receipt of participation request information of requesting device information of node device as connection candidate, and a device for transmitting the connection end candidate information thus determined to the node device which transmits the participation request information.