Different types of media (text, sound, animated images, . . . ) are transmitted to a relay center. According to the invention, this data is split up in terms of common synchronization points (PS0, . . . , PS4), and packets are assembled together combing all of the data of each media type that is defined between identical synchronization points. As a result, each packet contains data that is to be executed simultaneously on the telecommunications terminal. A particular application lies with mobile terminals.