Rate-based flow control of video services in ATM networks

A rate-based flow control method for ATM networks carrying video services is presented. In the proposed method the queue occupancy of each switching node is monitored against congestion and the users are advised to adjust their generated bit rates accordingly. Two threshold levels in the buffer are used to distinguish the congested state from the normal state. The impact of the threshold levels on both network and received image quality are presented. It is demonstrated that at congestion threshold of 50% of the buffer capacity the overall network performance and received image quality are optimised. Discrimination between the normal and congested states is made when the normal threshold level is 80% of the congested threshold level.