To compensate a failure in downloading of music piece data. For example,
when a viewer instructs purchase of a music pieceC to an IRD at a timing
t0 during the sixth transmission of music piece data, the music piece
data to be transmitted for the seventh time immediately after the
instruction is usually downloaded. When the downloading of the music
piece data transmitted for the seventh time fails for some reason,
downloading is re-executed on music piece data to be transmitted for the
eighth time. The music piece data for the final transmission time in each
of musical pieces is used for re-execution. Timing at which downloading
of the music piece data transmitted for the time immediately preceding
the final time can be instructed is set as purchase limit time by using
elapsed time since program start time.