Routing Strategies for Capacity Enhancement in Multi-hop Wireless Ad Hoc Networks

This thesis examines a Distributed Interference Impact Probing (DIIP) strategy for Wireless Ad hoc Networks (WANETs), using a novel cross-layer Minimum Impact Routing (MIR) protocol. Perfonnance is judged in tenns of interference reduction ratio, efficiency, and system and user capacity, which are calculated based on the measurement of Disturbed Nodes (DN). A large number of routing algorithms have been proposed with distinctive features aimed to overcome WANET's fundamental challenges, such as routing over a dynamic topology, scheduling broadcast signals using dynamic Media Access Control (MAC), and constraints on network scalability. However, the scalability problem ofWANET cannot simply adapt the frequency reuse mechanism designed for traditional stationary cellular networks due to the relay burden, and there is no single comprehensive algorithm proposed for it. DIIP enhances system and user capacity using a cross layer routing algorithm, MIR, using feedback from DIIP to balance transmit power in order to control hop length, which consequently changes the number of relays along the path. This maximizes the number of simultaneous transmitting nodes, and minimizes the interference impact, i.e. measured in tenns of 'disturbed nodes'. The perfonnance of MIR is examined compared with simple shortest-path routing. A WANET simulation model is configured to simulate both routing algorithms under multiple scenarios. The analysis has shown that once the transmitting range of a node changes, the total number of disturbed nodes along a path changes accordingly, hence the system and user capacity varies with interference impact variation. By carefully selecting a suitable link length, the neighbouring node density can be adjusted to reduce the total number of DN, and thereby allowing a higher spatial reuse ratio. In this case the system capacity can increase significantly as the number of nodes increases. In contrast, if the link length is chosen regardless ofthe negative impact of interference, capacity decreases. In addition, MIR diverts traffic from congested areas, such as the central part of a network or bottleneck points

Implementation and Evaluation of A Low-Cost Intrusion Detection System For Community Wireless Mesh Networks

Rural Community Wireless Mesh Networks (WMN) can be great assets to rural communities, helping them connect to the rest of their region and beyond. However, they can be a liability in terms of security. Due to the ad-hoc nature of a WMN, and the wide variety of applications and systems that can be found in such a heterogeneous environment there are multiple points of intrusion for an attacker. An unsecured WMN can lead to privacy and legal problems for the users of the network. Due to the resource constrained environment, traditional Intrusion Detection Systems (IDS) have not been as successful in defending these wireless network environments, as they were in wired network deployments. This thesis proposes that an IDS made up of low cost, low power devices can be an acceptable base for a Wireless Mesh Network Intrusion Detection System. Because of the device's low power, cost and ease of use, such a device could be easily deployed and maintained in a rural setting such as a Community WMN. The proposed system was compared to a standard IDS solution that would not cover the entire network, but had much more computing power but also a higher capital cost as well as maintenance costs. By comparing the low cost low power IDS to a standard deployment of an open source IDS, based on network coverage and deployment costs, a determination can be made that a low power solution can be feasible in a rural deployment of a WMN

Enabling Computational Intelligence for Green Internet of Things: Data-Driven Adaptation in LPWA Networking

With the exponential expansion of the number of Internet of Things (IoT) devices, many state-of-the-art communication technologies are being developed to use the lowerpower but extensively deployed devices. Due to the limits of pure channel characteristics, most protocols cannot allow an IoT network to be simultaneously large-scale and energy-efficient, especially in hybrid architectures. However, different from the original intention to pursue faster and broader connectivity, the daily operation of IoT devices only requires stable and low-cost links. Thus, our design goal is to develop a comprehensive solution for intelligent green IoT networking to satisfy the modern requirements through a data-driven mechanism, so that the IoT networks use computational intelligence to realize self-regulation of composition, size minimization, and throughput optimization. To the best of our knowledge, this study is the first to use the green protocols of LoRa and ZigBee to establish an ad hoc network and solve the problem of energy efficiency. First, we propose a unique initialization mechanism that automatically schedules node clustering and throughput optimization. Then, each device executes a procedure to manage its own energy consumption to optimize switching in and out of sleep mode, which relies on AI-controlled service usage habit prediction to learn the future usage trend. Finally, our new theory is corroborated through real-world deployment and numerical comparisons. We believe that our new type of network organization and control system could improve the performance of all green-oriented IoT services and even change human lifestyle habits

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Journal of Telecommunications and Information Technology, nr 3

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