Patent ID: 7328402

Claim:
A transmitting apparatus for transmitting a hierarchical structure of a directory for hierarchically managing locations of contents data, comprising: managing means for managing a hierarchical structure of a directory comprising a plurality of nodes, wherein each of said nodes is at a hierarchical level and comprises a container entry or a leaf entry, each of said container entries including information of nodes at lower hierarchical levels thereof, each leaf entry being located directly below one of the container entries, each leaf entry not including information of nodes at lower hierarchical levels thereof; detecting means for detecting a change of the hierarchical structure of the directory managed by said managing means, detecting a change tracking value of said hierarchical structure on the basis of the detected change, and obtaining first difference information and second difference information, the first difference information corresponding to the change of the hierarchical structure of container entries, the second difference information corresponding to the change of the hierarchical structure of leaf entries; generating means for generating first message and second message, the first message including said first difference information and a mask schema for interpreting a filtering mask, the second message including said second difference information and the filtering mask, wherein the filtering mask corresponds to information of one of the leaf entries being directly under one of the container entries; and transmitting means for separately transmitting said first message and said second message.