Study of impact of network and source time scales on feedback

In this study, the problem of multiplexing VBR and ABR traac is considered. VBR is uncontrollable, while ABR is provided the remaining service capacity in a controllable fashion. While in a given state, the VBR source is supposed to transmit at a xed rate; the VBR time scale is then deened in terms of the time constant associated with the rate of change of the rate of the VBR source. ABR sources are assumed to be at some distance from the multiplexing network node; the network speed deenes the network time scale which determines the distance (in network slots) between the ABR sources and the node. Finally, the minimum tolerable ABR rate (or the speed at which the ABR source can generate data units to be cellized) deene the source time scale. While it is known that the increased network transmission speed (decreased network time scale) reduces the eeectiveness of feedback-based adaptive rate control mechanisms due to the increased bandwidth propagation delay product, the positive impact of the VBR and ABR time scales has not been considered in the past. In this work a tractable analytical model is considered and the impact of the three time scales is investigated.