On the improvement of the quality of service of video services in an asynchronous transfer mode network using forced frame refreshment

A method of improving the quality of service of video services in an asynchronous transfer mode network under congestion periods is considered. In the event of cell loss carrying intraframe coded data, the decoder asks the encoder to refresh the codec by intraframe coding the next frame. To prevent the network from overloading, constraints are imposed on the maximum number of sources that refresh the whole picture simultaneously at the same video frame interval and the distance between two consecutive refreshments in each video connection. The rate of this refreshment depends on the network load and the number of sources sharing the network. It is shown that there is a minimum distance within two consecutive refreshments for each video connection where both network performance and perceived image quality are optimized.