A Novel Scheme for Wireless Hot-Spot Networks

In widely deployed wireless "hot-spot" networks, nodes frequently join or leave, inelastic/elastic and saturated/nonsatuarted flows coexist. In such dynamic and diverse environments, it is challenging to maximize the channel utilization while providing satisfactory user experiences. In this paper, we propose a novel contention-on-demand (CoD) MAC scheme to address this problem. The CoD scheme consists of a fixed-CW algorithm, a dynamic-CW algorithm, and an admission control unit. The fixed-CW algorithm allows elastic flows to access limited system bandwidth, the dynamic-CW algorithm enables inelastic flows to contend for channel on demand and quickly adapt to network change, and the admission control unit rejects overloaded traffic for providing good user experiences. We then perform an asymptotic analysis to develop a simple but efficient admission control rule. Finally, extensive simulations verify that our scheme is very effective and our theoretical result is very accurate.