Dynamic Call Admission Control and bandwidth redistribution scheme for 802.16 Systems

In this paper, we propose a new Call Admission Control (CAC) for 802.16 systems. The scheme is based on a dynamic adjustment of the bandwidth offered to all rtPS (Real time polling services) and nrtPS (Non real time plolling services) active connections, for each new connection establishment request in order to maximize the number of accepted connections, without affecting the quality of service offered to those ongoing connections. A linear programming formulation is also given for the bandwidth borrowing problem. Using the simulation results obtained with NS2, we demonstrate the effectiveness of our CAC, especially at maintaining the Quality of Service (QoS) level offered to real time traffic as high as it is possible.