An Intelligent Call Admission Controller for Guaranteed QoS in 4G Mobile Networks

摘要

Call admission control (CAC), a resource management function, is required to regulate network access toprovide the required levels of QoS to emerging services in Fourth Generation (4G) mobile networks.However, CAC is one of the challenging issues for quality of service (QoS) due to imprecise, uncertain andinaccurate measurements of network data. Although type-1 fuzzy system (T1FLS) can handle theuncertainties related to imprecise data, it cannot adequately handle new problems posed by the complexnature of data traffic and diversity of the QoS requirements of data users. This is because T1FLS ischaracterised by precise membership functions. This study presents an intelligent CAC controller for 4Gnetwork using interval type-2 fuzzy logic (IT2FL) for providing guaranteed QoS requirements. The IT2FLSwith fuzzy membership functions can fully cope with uncertainties associated with such dynamic networkenvironments by raising its accuracy for a better performance. The Karnik–Mendel (KM) iterativealgorithm and Wu-Mendel (WM) approach are explored for computing the centroid and to derive innerandouter-bound sets for the type-reduced set of IT2FS respectively. The study also implements a T1FLS –CAC for comparison with the KM and WM methods. The empirical comparison is made on the designedsystem with synthetic datasets. Simulation and analyses of results indicate that IT2FLS-CAC using WUapproach achieves minimal call blocking probability and provides high performance in CAC decisionmaking with a more reduced root mean square error (RMSE) than IT2FLS-CAC using KM and IT1FLSapproaches.