Abstract-We study in this paper the capacity of the downlink of OFDMA-based IEEE802.16 WiMAX system in the presence of two types of traffic, streaming and elastic. We focus in particular on the impact of Adaptive Modulation and Coding (AMC) as well as inter-cell interference resulting from different frequency reuse schemes. Several performance measures, namely blocking rates, mean transfer time and the mean number of collisions between two OFDMA WiMAX cells, are then derived and quantified. We show that reuse partitioning results in a lower blocking probability for streaming flows in the inner region but a much higher one for elastic flows in the outer region; the overall cell throughput increases meaning that the decrease in the number of collisions improves the overall throughput.
Abstract-OFDMA-based IEEE802.16 implements Adaptive Modulation and Coding (AMC) which results in a different bit rate for each user depending on its position in the cell as well as the radio condition it experiences; users away from the base station experience lower throughput. We hence propose in this paper a new QoS solution that compensates the degradation in modulation by a higher number of sub-carriers so as to maintain the bit rate of streaming flows at a constant level throughout the whole coverage area. This proposal is modeled analytically in a dynamic user configuration, where users of both types, streaming and elastic, remain in the system for a finite duration. And this in multi-cell environment and for different frequency reuse schemes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.