In the MPEG-2 standard a mechanism for time and clock-synchronisation between the encoder and decoder of audio/video data is foreseen based on a so-called PCR (Program reference clock), which is included in the distribution of a program. This synchronisation method serves the purpose to avoid buffer over- and underflow at the decoder due to clock drifts between the encoder and the decoder.
Additionally, the MPEG-2 standard allows the same mechanism to be used for network synchronisation; then the PCR is called ‘NCR’ (Network reference clock). Then, NCR special packets are inserted in the MPEG-2 Transport Stream (TS), which may consist of several programs. In the DVB-RCS standard the network synchronisation wrt timing and frequency based on NCR insertion has been adopted. The NCR distribution is accomplished via the DVB-S forward link.

This study analyses the impact of different disturbing effects on the NCR reception at a user terminal, such as phase noise and Satellite Doppler, on the reconstruction of network timing and frequency synchronisation. The network synchronisation performance is determined assuming different reference points (gateway or satellite) and topologies (one or more gateways) in the satellite system.