| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively utilize an unused channel obtained by optimizing transmission broadcasting waves to a plurality of broadcasting devices in a service area for constructing a broadcasting network by SFN (Single Frequency Network). <P>SOLUTION: The broadcasting network of the SFN is constructed by a system (a) of broadcasting apparatuses 120-12N. In this case, when a system (b) with a frequency differing from that of the system (a) is assigned from the broadcasting apparatuses 120-12N for additional service, arbitrary content is sent by radio by using the system (b) in the broadcasting apparatuses 120-12N, thus achieving VOD-compatible additional service. In the VOD-compatible broadcasting apparatuses 120-12N, when there is the VOD request of content erased from storages 200-20N, content requested mutually including subscriber terminals 13, 14 is searched. When the content is detected, transfer to a broadcasting apparatus that requested a search is made, or broadcasting is performed from the broadcasting apparatus having the content directly. <P>COPYRIGHT: (C)2008,JPO&INPIT |
