Constraint adaptive rate allocation scheme for QoS guarantee in packet-switched networks

Link sharing models and their implementations address various issues for QoS guarantee. As the service requirements of the network applications are diverse in the integrated service networks, it is required to provide differentiated services to the flows according to their flow characteristics, while guaranteeing the worst case performance of QoS. To meet such requirement, the adaptive rate allocation is essential and several researches have been done on that issue. However, in the research, to provide adaptive rates, the different rate allocation policies other than the links sharing policy are applied, which requires an additional runtime packet selection procedure in the system. In addition, the allocation policy uses the status of the flow at the instant, not the characteristics of the flow for the adaptive rate allocation. In this paper, we propose a new server capacity sharing scheme called Constraint Adaptive Rate Allocation (CARA) scheme. By decoupling the runtime rate and the worst case rate for a flow, the CARA scheme provides the differentiated services according to the traffic constraints, while guaranteeing the worst case QoS. As a consequence, the rates are adaptively allocated to the sharing flows according to their QoS constraints