Patent ID: 6697097
Filing Date: 2004-02-24
Classification: H04L,H04N

Abstract:
A method of synchronizing reproduction of voice signals and video signals in a video telephony call, said method comprising the steps of:transmitting said voice signals from a first telephone device of a first party to a second telephone device of a second party via a public switched telephone network (PSTN) connection; transmitting said video signals from a first computer of said first party to a second computer of said second party via packets in a computer data network, said video signals comprising successive video frames; determining a video latency time for transmission of said video signals over said computer data network; determining a voice latency time for transmission of said voice signals over said PSTN connection; and if said video latency time is in a first predetermined range then delaying transmission of said voice signals from said first telephone device to said second telephone device by a selected delay in response to said video latency time, said selected delay being no greater than a predetermined maximum voice delay; wherein said first predetermined range is between said voice latency time and said predetermined maximum voice delay.