Joint source-channel control for real-time VBR over ATM via dynamic UPC renegotiation

Asynchronous Transfer Mode (ATM) networks are expected to support variable bit rate (VER) traffic with quality-of-service (QoS) guarantees. At call set up time, a source is required to negotiate a set of Usage Parameter Control (UPC) parameters which the network uses in traffic enforcement and admission control. However, a static UPC can reflect neither the changing needs of the source nor the future onset of congestion in the network. Low resource utilization may result, particularly in the presence of VER sources with significant slow time-scale traffic variations if the source chooses its UPC parameters based on worst-case resource requirements. This paper proposes and evaluates the performance of a joint source-channel control scheme for VER traffic service in which sources may dynamically renegotiate UPC parameters with the network during a session.