PACE: Simple Multi-hop Scheduling for Single-radio 802.11-based Stub Wireless Mesh Networks

IEEE 802.11-based Stub Wireless Mesh Networks (WMNs) are a cost-effective and flexible solution to extend wired network infrastructures. Yet, they suffer from two major problems: inefficiency and unfairness. A number of approaches have been proposed to tackle these problems, but they are too restrictive, highly complex, or require time synchronization and modifications to the IEEE 802.11 MAC. PACE is a simple multi-hop scheduling mechanism for Stub WMNs overlaid on the IEEE 802.11 MAC that jointly addresses the inefficiency and unfairness problems. It limits transmissions to a single mesh node at each time and ensures that each node has the opportunity to transmit a packet in each network-wide transmission round. Simulation results demonstrate that PACE can achieve optimal network capacity utilization and greatly outperforms state of the art CSMA/CA-based solutions as far as goodput, delay, and fairness are concerned

Strategies for resolving security and interference issues in 802.11 wireless computer networking : a thesis presented in partial fulfilment of the requirements for the degree of Masters in Engineering in Computer Systems Engineering at Massey University, Palmerston North, New Zealand

This thesis presents the outcomes of the research and development of strategies to improve 802.11 wireless networking security, reduce interference, and investigation into the trends of home users in the city limits of Palmerston North, New Zealand. The main contributions of the research are several types of improvement strategies that reduce interference, add additional layers of security to 802.11, and reports on wireless trends. The thesis begins with an overview of the current 802.11 security protocols and related issues. The current state of the 802.11 security is presented along with an assessment of efficacy of 802.11. Lastly, the motivations for improving security and reducing interference are explained. The main improvement presented within the thesis is that of client filtering. The operation of filtering is explained. Using methods from other filtering protocols its shown that how an additional layer of security can be added to 802.11. Following this, more improvements are shown that can be used with or without client filtering. The use of smart aerials, wizards and frequency selective materials is discussed and the advantages and disadvantages of each are highlighted, as well as the aspects and issues of implementing the strategies on a home personal computer based platform are presented. This is followed by a description of the experiments conducted into attenuation and direction sensing. The results of the experiments are presented along with the discussion. Finally, conclusions about the improvements are detailed and the results shown, in addition to research conducted on the trends of 802.11 users to further highlight the need for this research

Throughput optimization strategies for large-scale wireless LANs

Thanks to the active development of IEEE 802.11, the performance of wireless local area networks (WLANs) is improving by every new edition of the standard facilitating large enterprises to rely on Wi-Fi for more demanding applications. The limited number of channels in the unlicensed industrial scientific medical frequency band however is one of the key bottlenecks of Wi-Fi when scalability and robustness are points of concern. In this paper we propose two strategies for the optimization of throughput in wireless LANs: a heuristic derived from a theoretical model and a surrogate model based decision engine