Optimal Circuit Access Policies in an ISDN Environment: A Markov Decision Approach

We address the problem of determining optimal access policies for circuit-switched networks that support traffic types with varying bandwidth requirements. We suppose that the network supports K classes of calls where each class is determined by a fixed route and a bandwidth requirement. A Markov decision process (MDP) approach is employed to obtain optimal access policies for three models: the flexible scheme access-port model where a single link is shared; the contiguous scheme access-port model where wideband calls are required to occupy specific contiguous regions of the TDM frame; the network-access model where a call holds several channels in different links simultaneously. Both linear programming and value-iteration MDP algorithms are coupled with a novel state descriptor in order to locate the optimal policy for reasonable size problems (several T1 carriers in parallel for access-port case, and small networks of T1 carriers for the network-access case).