A data transmission apparatus has a multiplexing unit that cyclically multiplexes presentation information and navigation information stored in a transmission data storage unit according to control by a multiplexing control unit and a transmission unit that transmits the multiplexed stream. The reception...http://www.google.de/patents/US6353930?utm_source=gb-gplus-sharePatent US6353930 - Digital broadcasting system, digital broadcasting apparatus, and receiver apparatus for digital broadcasters
