| 摘要 |
A packet transmission system in which variable delays are compensated for by packetizing an input signal so as to produce packets at a predetermined packet frequency (3), allocating a sequence number to each packet (6), transmitting these packets over a network to an endpoint (7), and forming the packets into an output signal at the endpoint by reference to their sequence number (12) and by delaying each as necessary (9,10) so that they are all delayed by substantially the same predetermined delay time with reference to said packet frequency. Preferably, the delay in the transmission of each packet through the network is measured by comparison of the time of arrival of the packet at the endpoint relative to a timing signal (11) synchronised with or running plesiochronously with said predetermined packet frequency. The endpoint delay is then set so that the sum of the measured delay and the endpoint delay is substantially equal to said predetermined delay time, which is assessed as the maximum delay for acceptable output signal quality. <IMAGE> |
