On network bandwidth sharing for transporting rate-adaptive packet video using feedback

While existing research shows that feedback-based congestion control mechanisms are capable of providing better video quality and higher link utilization for rate-adaptive packet video, there has been relatively little study on how to share network bandwidth among competing rate-adaptive video connections, when feedback control is used in a fully distributed network. This paper addresses this issue by presenting a framework of network bandwidth sharing for transporting rate-adaptive packet video using feedback. We show how a weight-based bandwidth sharing policy can be used to allocate network bandwidth among competing video connections and design a feedback control algorithm using an Available Bit Rate (ABR)-like #ow control mechanism. A novel video source rate adaptation algorithm is also introduced to decouple a video source's actual transmission rate from the rate used for distributed protocol convergence. Our feedback control algorithm provides guaranteed convergence and smooth source rate adaptation to our weight-based bandwidth sharing policy under any network con"guration and any set of link distances. Finally, we show the on-line minimum rate renegotiation and weight adjustment options in our feedback control algorithm, which o!er further #exibility in network bandwidth sharing for video connections. Copyright ( 2000 John Wiley & Sons, Ltd.