HMM: hybrid multipolling mechanism with pre-allocation admission control for real-time transmissions in WLANs

The needs of multimedia applications inspirits the IEEE 802.11e MAC protocol as an emerging supplement to WLANs for supporting QoS transmissions. In recent years, the demand for supporting real-time communications has become more and more important in multimedia wireless networks. However, the IEEE 802.11e standard does not provide a sufficient real-time scheduling algorithm to support dynamic admission control of the bounded delay requirements of real-time traffic. Thus, in this paper, we propose a dynamic requirement allocation scheme named hybrid multipolling mechanism (HMM). which is based on the hybrid coordination function (HCF) of the IEEE 802.11e, to enhance the utilization of network bandwidth. Moreover, in order to make better use of the HMM, we provide an admission control, named pre-allocated admission control (PAC), to provide more real-time services. The simulation results show that the proposed HMM increases the channel utilization and reduces the control overhead very well. We also show that our scheme guarantees time bounded services as well as maximizes the network utilization.