Automatic compensation of a delay of a synchronization signal in a packet switching network

Sending device able to send packets in a packet communication network comprising at least two stations, said device comprising:

• means for extracting image pips on the basis of a synchronization signal;
• means for initializing an image counter on the basis of the said image pips;
• means for initializing a counter every “m” zero-crossings of the image counter, the counter being regulated by a clock produced by the image counter;
• means for sampling the counter every period Tsmp, where Tsmp emanates from a time base synchronized on all the stations of the said network;
• and
• means for sending packets containing the samples of the counter in the network,
• wherein it further comprises:
• means for receiving packets containing samples sent by a station of the network as echo to the samples;
• means for evaluating a duration of propagation of samples over an outward-return trip between the said device and the said station when samples are received;
• means for determining a phase shift value ΔΦ on the basis of the duration of propagation;
• means for sending the phase shift value ΔΦ in the network.

Reception device able to receive packets in a packet communication network comprising at least two stations, said device comprising:

• means for receiving packets containing samples of the said network, the said samples originating from data sampled every period Tsmp, where Tsmp emanates from a time base synchronized on all the stations of the said network;
• means for regenerating a counting ramp with the aid of a phase-locked loop receiving the samples and furthermore delivering local samples every period Tsmp and a reconstituted clock;
• means for initializing, at every zero-crossing of the counting ramp, an image counter which is regulated by the reconstituted clock;
• means for generating image pips every zero-crossing of the said image counter;
• and
• means for reconstituting a synchronization signal on the, basis of the said image pips;
• wherein it further comprises:
• means for receiving packets containing a phase deviation value ΔΦ;
• means for sending in the network packets containing the local samples;
• means for phase-shifting the samples received by the phase shift value ΔΦ, to generate phase-shifted samples when the phase shift value ΔΦ is received;
• means for supplying the phase-locked loop with the phase-shifted samples.