The effect of topology control for wireless multi-hop networks
Wireless multi-hop networks are not restricted to rural development efforts. They have found uses in the military, industry, as well as in urban areas. The focus of this study is on stationary wireless multi-hop networks whose primary purpose is the provisioning of Internet access using low cost, resource-constrained network nodes. Topology control algorithms have not yet catered for low cost, resource-constrained network nodes resulting in a need for algorithms that do cater for these types of wireless multi-hop network nodes. An algorithm entitled "Token-based Topology Control (TbTC)" was proposed. TbTC comprises three components, namely: transmit power and selection, network connectivity and next node selection. TbTC differs significantly in its treatment of the synchronisation required for a topology control algorithm to work effectively by employing a token to control the execution of the algorithm. The use of the token also ensures that all the network nodes eventually execute the topology control algorithm through a process called neighbour control embedded within the next node selection component. The proposed topology control algorithm, TbTC was simulated using ns-2 and the performances of a 30-node network before and after the algorithm was utilised, were compared. The Packet Delivery Ratio, Delay. Routing Protocol Overhead and Power Consumption were used as the simulation parameters. The neighbour control process was found to significantly reduce the number of hops taken by the token to visit each network node at least once. It was found that this process shortened the token traversal by 37.5%. Based on the results of its simulation, TbTC proves the positive benefits that can be accrued to the use of tokens in topology control as well as highlighting the negative benefits of the creation of uni-directional links in wireless multi-hop networks that utilise the IEEE 802.11 standard.
Networked Digital Library of Theses and Dissertations