Adaptive Call Admission Control in Circuit-Switched Networks

by

Kagan Gokbayrak

Bilkent University

We consider threshold-based admission control policies for traffic in fixed-route circuit-switched networks and develop a scheme for adjusting the threshold parameters on-line so that, as operating conditions in the network change, the thresholds "adapt" with the objective of minimizing a weighted sum of call blocking probabilities. Instrumental in this scheme is an algorithm for estimating on-line the sensitivity of the call blocking metric with respect to thresholds. The formal optimization problem over the set of discrete threshold parameters is solved by means of a conversion to an optimization problem over a set of auxiliary real-valued parameters. Such threshold-based policies, though conservative at low traffic rates, have the advantage of being simple to implement, distributed in nature, adaptive, and not requiring explicit distributional modeling assumptions. Numerical results indicate that at higher traffic rates these simple policies yield the same performance as more complex and less flexible call admission schemes