Abstract: In the field of the broadcasting of digital services intended for terminals retrieving these services, the concern is with the problem of synchronisation in the context of a network transmitting on a single modulation frequency and the reliability of the broadcasting channel by redundancy of equipment. The present invention proposes a broadcasting system having a duplicated formatting module. This system enables a modulator to switch between the two streams generated by the two formatting modules without becoming desynchronised. These formatting modules are synchronised with each other in order to generate synchronised streams. Thus, when a modulator is caused to switch from a first stream generated by one of the formatting modules onto a second stream generated by a second formatting module, this switching can be effected without requiring a resynchronisation step.

Abstract: A contribution system where the national services are not duplicated in the single stream. This single stream is transmitted in a mode not implementing burst transmission. Advantageously, the single stream is not protected by an FEC error correcting code, as present in the radio broadcast standard, for example DVB-H. Synchronisation is provided by the insertion by the concentrator of synchronisation packets comprising three synchronisation stamps. A first stamp serves to synchronise the deconcentrators with each other and with the concentrator. A second stamp generates a first synchronisation signal allowing synchronous generation of the period of the burst transmission mode necessary for generating the regional signal. The third stamp serves to generate a second synchronisation signal for generating so-called “MIP” synchronisation packets for synchronising the various modulators.