| 摘要 |
<p>Provided is a message transmission device that can individually identify reception devices and distribute messages from a broadcast provider, even without the use of IC cards, and that can manage, on the broadcast provider side, the number of reception devices implementing viewing restrictions. Message reception devices (5B) notify a message transmission device (1B) of individual identifiers, after which the message transmission device (1B) transmits individual messages to the individual identifiers, said individual messages containing message control information for grouping the message reception devices (5B). While updating fragment identifiers in order to switch, in units of sub-groups, message reception devices (5B) that receive shared messages containing message information, the message transmission device (1B) generates and transmits the shared messages to the message control information, the section ID that sub-groups the digital broadcast reception devices (5B), and mask information that specifies the region of a part (fragment identifier) of the individual identifier.</p> |
