Delivery delay compensation on synchronised communication devices in a packet switching network

Reference station able to deliver packets in a packet switching network to communication devices connected to the network, said reference station comprising:

• means for retrieving image ticks from a sync signal received by said reference station;
• means for initializing an image counter from those image ticks;
• means for initializing a counter at each mth reset of the image counter, the counter being cadenced by a clock produced by the image counter;
• means for sampling the counter at each Tech period, Tech being issued by a time base synchronized on all stations of the network, and
• means for delivering packets comprising samples of the counter, wherein it further comprises means for inserting at least a temporal offset in said packets, wherein said temporal offset describes a data delivery duration on a pre-determined path of said network.

Receiving communication device connected over a packet switching network, said receiving device being able to receive packets from a reference station connected to the network, said receiving device being able to receive data stream from emitting communication devices being connected to the network, said receiving communication device comprising:

• means for receiving packets comprising samples, said samples resulting from a sampling operation realized at a Tech period, Tech being issued by a time base synchronized on all stations of the network;
• means for generating a counter ramp with a Phase Locked Loop receiving the samples and delivering a synthesized clock and local samples at each Tech period;
• means for initializing an image counter cadenced by the synthesized clock each time the counter ramp is equal to zero;
• means for generating image ticks each time the image counter is equal to zero;
• means for generating a sync signal from the said image ticks;
• wherein it further comprises:
• means for receiving at least a temporal offset value inserted in said packets;
• means for receiving data stream from sending communication device;
• means for determining from received data stream which temporal offset it has to consider among received temporal offsets;
• means for shifting temporally the received data stream with considered temporal offset.

Sending communication device connected over a packet switching network, said sending device being able to receive packets from a reference station connected to the network, said sending device being able to send data stream over the network, said sending device comprising:

• means for receiving packets comprising samples, said samples resulting from a sampling operation realized at a Tech period, Tech being issued by a time base synchronized on all stations of the network;
• means for generating a counter ramp with a Phase Locked Loop receiving the samples and delivering a synthesized clock and local samples at each Tech period;
• means for initializing an image counter cadenced by the synthesized clock each time the counter ramp is equal to zero;
• means for generating image ticks each time the image counter is equal to zero;
• means for generating a sync signal from the said image ticks;
• wherein it further comprises:
• means for sending data stream over the network synchronously to the sync signal;
• means for inserting an identification of said sending communication device in said data stream.