An SNR-Based CAC Algorithm for Optimizing Resource Assignment in the Downlink of M-WiMAX

In order to overcome the inherently challenging conditions of the mobile environment, the physical layer of 802.16e has utilized an Adaptive Modulation and Coding (AMC) scheme, capable of compensating for any SNR (Signal-to-Noise Ratio) fluctuations. As a result, the actual bandwidth demands of each data flow are not solely defined by its datarate requirements, but they are also highly dependent on the terminal´s channel conditions. In this respect, the present paper introduces an efficient CAC (Connection Admission Control) algorithm, capable of optimizing the network revenue while guaranteeing the required QoS, under the bandwidth-limited and time-varying conditions of the IEEE 802.16e architecture. The proposed algorithm makes virtue of the terminals´ SNR patterns so as to maximize the accuracy of the resource reservation predictions.