Information service broadcasting or multicasting

摘要

A receiver (FIG. 2), receives IP session announcement signals from a terrestrial digital video broadcasting system. Each IP session announcement (RM) includes information concerning announcements on an immediately lower level as well as information identifying the quantity of announcement data, such as the number of announcement messages, and a timeout value. The quantity data tells the receiver how many messages X1 to X3 it needs to receive (C) before it has received all the relevant announcement messages. The timeout value informs the receiver how long it can wait before again receiving the messages X1 to X3 (which may have changed in content by then). After initially receiving the messages X1 to X3, the receiver may sleep (E), or it may receive announcement messages from another channel Y (D).