In next generation cellular networks, Quality of Service (QoS) delivery will need more network resources per user, leading to network congestion problems. Call Admission Control (CAC) is the process in charge of managing calls according to the availability of network resources. In order to overcome the problem of network congestion, the CAC should tackle pricing policies, improving by the same way the network utilization and providing required levels of QoS to emerging services. Thus, modeling network behaviors, regarding the number and type of calls is not straight forward and needs to consider uncertainty related to the network traffic. Fuzzy logic is an appropriate technique to tackle uncertainties in network traffic modeling and call management. Thus, this paper presents a Fuzzy Logic based Controller (FLC) for call management in next generation cellular networks. Depending on how we consider the uncertainty modeling, we will discuss two classes of FLC; Type-1 and Type-2. Simulation results are given in order to analyze the interest of each class of FLC.