Synchrony™

The modulation properties of COFDM enable DVB-T operators to build single frequency networks (SFN). In a SFN installation, all transmitters broadcast on the same frequency. Although this broadcast mode optimizes the occupation of the spectrum, it requires perfect synchronization of every transmitter. A leader in DVB-T since 1996, Harris Broadcast Europe has acquired unique experience and expertise in technologies that achieve the precise synchronization required by SFNs.

Synchrony™ is a device that is necessary for synchronization of DVB-T transmitters operating as a SFN. Synchrony receives a 1 pps time reference and a 10 MHz clock reference from a GPS receiver, computes time and control information to build the megaframe initialization packet (MIP). MIP information is inserted in the MPEG-2 transport stream and used by transmitters to synchronize the modulation process.

With its standard ASI inputs and outputs and powerful integrated features such as bit rate adaptation, PCR restamping and NIT updating, Synchrony can be used in any SFN head-end, and in combination with any DVB multiplexer.

Synchrony is able to process two MPEG-2 transport streams in parallel, with the required synchronization, for use of hierarchical modulation in the SFN network.