METHOD OF ANNOUNCING SESSIONS

摘要

An electronic service guide (ESG) is provided by transmitting announcements describing multimedia sessions, such as video streams. Sessions are organised into a session directory ( 28 ) which is split into two parts: a full session directory ( 291 ) and an updated session directory ( 292 ). A first kind of announcement describes all sessions in the full session directory. A second kind of announcement describes sessions in the updated session directory. Once a client has received a description of the full session directory, it need only listen to announcements of the second type so as to learn of any updates to sessions.