A Fuzzy Logic Approach to Solve Call Admission Control Issues in CDMA Systems

Call Admission Control (CAC) plays a basic role in 3 Generation networks (3G), properly accommodating new connection requests while ensuring seamless service provision to the existing connections. CAC is classically based on Signal to Interference Ratio estimates and threshold comparisons in 3G networks adopting CDMA access technique. A novel CAC strategy founded on Fuzzy Logic is proposed in this paper for CDMA systems and, in particular, for UMTS. Starting from cell parameters like congestion state, available load and total interference a fuzzy set is defined. A fuzzy rule base is then constructed, giving the rules for the admission criterion. Simulation results came out from a realistic “ad hoc” UMTS radio access simulator show the improvements attained by the proposed policy with respect to the classic admission control strategies.