Admission Control in UMTS Networks based on Approximate Dynamic Programming

This paper presents a Connection Admission Control (CAC) algorithm for Universal Mobile Telecommunications System (UMTS) networks based on an Approximate Dynamic Programming (ADP) approach. To deal with the non-stationary environment due to the timevarying statistical characteristics of the offered traffic, the admission policy has to be computed periodically based on on-line measurements. If standard algorithms are used, the optimal policy computation is excessively time-consuming to be performed on-line. Thus, an ADP approach for the computation of a sub-optimal admission policy is proposed. TheADPapproach is based (i) on the reduction of the policy space, and (ii) on an approximated state-space aggregation. Theoretical results and numerical simulations show the effectiveness of the proposed approach, which is currently being implemented in a real UMTS testbed.