Structural properties of optimal policies in an ISDN circuit-switched access port

The authors are concerned with access policies for networks using multi-rate circuit switching. The access node consists of F bandwidth units, which simultaneously support K classes of calls with varying bandwidth requirements. A policy specifies which calls should be accepted as a function of the system state. They consider finding policies which maximize the average revenue. They first prove that for K=2, the optimal policies are of simple threshold type, with thresholds occurring only at the points where the number of idling channels are integral multiples of the bandwidth ratio. For the general case of K user classes, the authors consider the problem of finding the optimal static policy, where for each user class a portion of the channel is dedicated. An efficient finite-stage dynamic programming algorithm for locating the optimal static policy is presented. Furthermore, variants of the optimal static policy which allow some sharing among user classes are also discussed.<>