Method and apparatus for correcting a packet delay variation

A transmitter for transmitting traffic which includes express traffic comprising high-priority express packets interspersed at the transmitter by a preemption mechanism with a best effort traffic comprising low-priority best effort packets,

• said transmitter comprising:
• a processing unit adapted to calculate a preemption delay value, PRDV, which indicates a preemption delay, PD, introduced by the preemption mechanism;
• and
• an insertion unit adapted to write the calculated preemption delay value, PRDV, into a delay header field of a header of a high-priority packet transmitted by said transmitter via a signal line to a receiver.

A receiver for receiving traffic which includes express traffic comprising high-priority express packets interspersed at a transmitter by a preemption mechanism with best effort traffic comprising low-priority best effort packets,

• said receiver comprising:
• an extraction unit, adapted to extract a preemption delay ay value, PRDV, from a delay header field of a header of a high-priority express packet received by the receiver via a signal line from the transmitter;
• a processing unit, adapted to calculate a variation compensation delay, VCD, value by subtracting the extracted preemption delay value, PRDV, from a predetermined worst-case preemption delay value, PRDVworst;
• and
• a dynamic delay unit, adapted to apply an additional delay to the high-priority express packet according to the calculated variation compensation delay, VCD, value to compensate the preemption delay, PD, introduced by the preemption mechanism at the transmitter.

A transmission system comprising at least one transmitter for transmitting traffic which includes express traffic comprising high-priority express packets interspersed at the transmitter by a preemption mechanism with a best effort traffic comprising low-priority best effort packets, said transmitter comprising:

• a processing unit adapted to calculate a preemption delay value, PRDV, which indicates a preemption delay, PD, introduced by the preemption mechanism;
• and
• an insertion unit adapted to write the calculated preemption delay value, PRDV, into a delay header field of a header of a high-priority packet transmitted by said transmitter via a signal line to a receiver;
• said receiver comprising:
• an extraction unit, adapted to extract a preemption delay value, PRDV, from a delay header field of a header of a high-priority express packet received by the receiver via a signal line from the transmitter;
• a processing unit, adapted to calculate a variation compensation delay, VCD, value by subtracting the extracted preemption delay value, PRDV, from a predetermined worst-case preemption delay value, PRDVworst;
• and
• a dynamic delay unit, adapted to apply an additional delay to the high-priority express packet according to the calculated variation compensation delay, VCD, value to compensate the preemption delay, PD, introduced by the preemption mechanism at the transmitter;
• wherein the transmitter and the receiver are connected to each other via a signal line of the transmission system.