In this paper, the IEEE 802.16 protocol is investigated with respect to the bandwidth provision problem arising at the medium access control (MAC) layer. The aim is to optimally tune the resource allocation to match QoS requirements. Traffic flows are originated at network layers overlying the 802.16 protocol stack. This leads to the investigation of a novel control algorithm, suited to optimal bandwidth allocation and call admission control in the presence of statistically heterogeneous flows. Specific implementation details are provided to match the application of the control algorithm using the regular 802.16 request-grant protocol. Simulation results validate the proposed approach.