Adaptive VBR video traffic management for higher utilization of ATM networks

Abstract

The VBR video traffic exhibits high burstiness and correlation properties that are quite complex to be captured by a single traffic model. Efficient resource management based on few parameters of the source traffic is highly desirable. The real-time VBR video traffic has stringent quality of service (QoS) requirements such as delay (few milliseconds) and cell loss (1 in 10-5) that are difficult to achieve with good utilization (> 0.6) by static bandwidth allocation schemes. In order to satisfy such QoS constraints with good utilization, proper adaptive mechanisms have to be devised. This paper presents a dynamic bandwidth allocation scheme for VBR video traffic based on buffer monitoring and a simple LMS (least mean square) traffic prediction system. The goal is to reduce the frequency of the bandwidth reallocations and at the same time reduce the Cell-loss Ratio (CLR) with increased utilization. Simulation results indicate that utilization up to 0.8 can be achieved by the proposed scheme even under high source alignment [26] for bursty VBR video traffic. It is found that the proposed adaptive scheme outperforms the static FCFS allocation scheme with lower buffer requirements and fewer (< 5%) bandwidth reallocations.