Wireless network segregation utilising modulo in industrial environments

Student thesis: Doctoral Thesis


With the success of wireless technologies in consumer electronics, standard wireless technologies are envisioned for the deployment in industrial environments as well. Industrial applications involving mobile subsystems or just the desire to save cabling make wireless technologies attractive. In industrial environments, timing and reliability are well catered by the current wired technologies. When wireless links are included, reliability and timing requirements are significantly more difficult to meet, due to the common problems that influence them such as interference, multipath and attenuation.

Since the introduction of the IEEE 802.11 standard, researchers have moved from the concept of deploying a single channel and proposed the utilisation of multiple channels within a wireless network. This new scheme posed a new problem, the ability to coordinate the various channels and the majority of the proposed works focus on mechanisms that would reduce the adjacent channel interference caused by the use of partially overlapping channels. These mechanisms are mainly algorithms that define rules to the allocation of the channels for the wireless nodes during each transmission. Many of the approached proposed during the last years have two very common disadvantages, they are hard to implement in real life and they do not take full advantage of the available spectrum, because they use only non-overlapping channels. The industries demand for solutions which would not move away from using proprietary hardware and software and any changes required to be made should not limit the availability of support for their networks. This would keep the cost low as it is the main factor that industries decide to replace their wires with radio links.

The proposed idea in this thesis borrows the concept of network segregation, firstly introduced for security purposes in wired networks, by dividing a wireless network into smaller independent subnetworks and in collaboration with a channel assignment, the Modulo. Modulo defines a set of rules that nodes should obey to when they transmit data. The utilization of multiple channels under the guidance of Modulo for each subnetwork, proves to improve the performance of an ad-hoc network even in noisy industrial environments with high levels of interference from external sources.
Date of AwardFeb 2010
Original languageEnglish
SupervisorMo Adda (Supervisor) & Paul Gnanayutham (Supervisor)

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