A Dynamic Admission Control for IEEE802.16e Wireless Network

The grunt/request mechanism in IEEE 802.16e MAC provides different quality of service (QoS) for different service flows, wherein the call admission control (CAC) comparing the network resource available in the system with requirement of the QoS of the connection to decide if a connection can be admitted is an important stage to guarantee the QoS of each connection. Aiming at the current CAC´s shortcoming of lower utilization of network resource and incomplete guarantee of QoS due to a static, constant and identical network resource for each connection, a dynamic resource allocation based admission control is proposed in this paper. In order to realize the dynamic admission control, a user-oriented based connection-oriented resource allocation is investigated at first in this paper. The novel CAC works together with such adaptive resource allocation based on OFDMA, where the resource is distributed to each connection according to the priority of the connection and channel condition of the user subjected to the connection´s QoS and the admission decision is made by satisfaction to requirement of QoS, so the QoS of the connection is guaranteed, meanwhile, the utilization of network source can be maximized. The simulation results reveal that the number of the user admitted with the novel strategy and the utilization of the network resource is much larger than that with traditional algorithm.