In this thesis we investigate the performance of spatial reuse in wireless networks. More specifically, we investigate the performance of location-based spatial reuse built upon the identification of links in the network that form Collision-Free Sets (CFSs). We develop algorithms that efficiently find such CFSs. The main focus of this thesis is the application of our CFS-based algorithms to emerging WiMAX (Worldwide Interoperability for Microwave Access) networks. However, we will also apply our CFS-based algorithms to smaller scale networks, as well as to the issue of QoS routing. This thesis makes several contributions. We first show how CFSs can be found within polynomial time in small scale wireless networks. We then probe how CFSs can be used to enhance network efficiency when location is available. We also explore how CFS determination is affected by location error, determining what level of location error renders the use of CFSs ineffective. In this context, we discuss the density of access points required to ensure CFS-based spatial reuse remains effective. We then focus on the use of CFSs in emerging multihop WiMAX networks, showing in detail how enhanced spatial reuse is delivered. The spatial reuse gains are probed both in the presence of realistic channel conditions and realistic location errors. Within the context of the IEEE 802.16 standard we show how CFSs can enhance, by factors of two, the VoIP capacity of multihop WiMAX networks. We also discuss how our CFS algorithms can be applied to other ongoing efforts aimed at improving VoIP capacity in WiMAX networks. Finally, an application of our CFS algorithms in the context of QoS routing is studied. Specifically, we develop a two-hop QoS routing protocol that guarantees QoS specifications by securing higher bandwidth for the chosen routes.
| Identifer | oai:union.ndltd.org:ADTP/205193 |
| Date | January 2008 |
| Creators | Oh, Inhee, Electrical Engineering & Telecommunications, Faculty of Engineering, UNSW |
| Publisher | Publisher:University of New South Wales. Electrical Engineering & Telecommunications |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://unsworks.unsw.edu.au/copyright, http://unsworks.unsw.edu.au/copyright |
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