CAC-RD: A Call Admission Control for UMTS Networks

This work proposes CAC-RD: a call admission control for UMTS (universal mobile terrestrial system) networks. Its main challenge is to guaranty the maximum access/network availability while maintaining satisfactory performance levels. It is based on two schemes: channel reservation and network diagnosis. It reserves dynamically some channels to handovers, based on the network behavior. The diagnosis monitors the network utilization giving information to the CAC-RD decisions. There are some utilization thresholds that drive the blockings, telling CAC-RD when to accept or not a new call. Handovers and the conversational class are the CAC-RD priorities. Simulation results show that CAC-RD can guarantee network availability, reducing priority classes blocking and guarantying some network QoS requirements. Simulations had shown an average reduction of 40% and 11% in handovers and new classes blockings, respectively. Thus, results indicate that CAC-RD can guarantee access and QoS, keeping levels of agreement between performance and availability.