A dynamic QoS-aware call admission control algorithm for mobile broadband networks

Call admission control (CAC) is one of the vital components in the management of the scarce wireless network resources in mobile broadband networks. Recently, a QoS-aware CAC algorithm with Bandwidth Reservation (BR) and Bandwidth Degradation (BD) (QACAC-BR-BD) was proposed to improve resource utilization and ensure QoS for all classes. However, the algorithm wastes network resources due to a static bandwidth degradation mechanism used to degrade existing connections without recourse to the amount of resources needed in the presence of inadequate resources. A dynamic QoS-Aware CAC (DQACAC) scheme is proposed to improve resource utilization. The DQACAC employs a pre-bandwidth degradation technique to determine whether the amount of resources obtained from the degradation will be sufficient or otherwise for the requesting connection. The algorithm also employs a dynamic BD mechanism to degrade different amount of resources from existing connections when resources are insufficient. We conducted extensive simulation experiments to assess the efficiency of the proposed algorithm. The simulation results indicate that the proposed scheme outperforms the benchmark scheme in terms of reducing the New Connections Blocking Probability (NCBP); thus, resulting to an efficient resource utilization.