A novel contention-on-demand design for WiFi hotspots. Issue 5 (October 2016)

• Record Type: Journal Article
• Authors: Feng, Li; Yu, Jiguo; Cheng, Xiuzhen; Atiquzzaman, Mohammed
• Is Part Of: Personal and ubiquitous computing. Volume 20:Issue 5(2016)
• Page Start: 705
• Page End: 716
• Publication Date: 2016-10
• Subjects: IEEE 802.11 -- "Hot-spot" networks -- Admission control; Mobile computing -- Periodicals; Portable computers -- Periodicals; Human-computer interaction -- Periodicals; 004.16
• DOI: 10.1007/s00779-016-0942-8
• Languages: English
• ISSNs: 1617-4909

Abstract

Abstract In widely deployed wireless "hot-spot" networks, nodes frequently join or leave, and inelastic/elastic and saturated/nonsaturated 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 rule. 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 rule rejects overloaded traffic for providing good user experiences. We then perform an asymptotic analysis to develop a simple and practical admission control rule for homogeneous and heterogeneous traffic; our rule can not only adapt to the change in offered loads and node number, but also maximize the system utilization . Finally, extensive simulations verify that our scheme is very effective and our theoretical result is very accurate.