Admission control in deadline-based network resource management

In our deadline-based network resource management framework, each application data unit (ADU) is characterized by a (size, deadline) pair, which can be used to convey the resource and QoS requirements of the ADU. Specifically, the ADU´s bandwidth requirement can be implicitly estimated by the ratio: size / (deadline - current time), and the time at which the ADU should be delivered is specified by the deadline. The ADU deadline is mapped onto deadlines at the network layer, which are carried by packets and used by routers for channel scheduling. In an earlier work, we have shown that deadline-based channel scheduling achieves good performance in terms of the percentage of ADUs that are delivered on-time. However, when a network is under heavy load, congestion may occur, and deadline-based scheduling alone may not be sufficient to prevent performance degradation. The level of congestion can be reduced by admission control. In this paper, two application-layer admission control algorithms are developed. The performance of these two algorithms is evaluated by simulation.