Deploying rural community wireless mesh networks

Inadequate Internet access is widening the digital divide between town and countryside, degrading both social communication and business advancements in rural areas. Wireless mesh networking can provide an excellent framework for delivering broadband services to such areas. With this in mind, Lancaster University deployed a WMN in the rural village of Wray over a three-year period, providing the community with Internet service that exceeds many urban offerings. The project gave researchers a real-world testbed for exploring the technical and social issues entailed in deploying WMNs in the heart of a small community

Fine recycled concrete aggregate as a material replacement in concrete production

As a fast and rapid growing nation, Malaysia undergoes a lot of development especially in construction field. Most of the building nowadays are being made mainly using concrete as it provides many favorable features such as satisfactory compressive strength, durability, availability, versatility and cost effectiveness. However, in pursuing the development era, sometimes the authorities overlooked about the construction and demolition (C&D) waste that had been created along the development progress. Construction and demolition waste is becoming a vital issue especially to the environmental aspect in many large cities in the world (Chen et al., 2002). Shen [1] describe C&D waste as the waste which generated from renovation, site clearing, demolition, construction, roadwork, land excavation and civil and building construction. Construction and Demolition (C&D) waste constitutes a major portion of total solid waste production in the world, and most of it is used in landfills .

High resilience wireless mesh networking characteristics and safety applications within underground mines

The work presented in this thesis has investigated the feasibility, characteristics and potential applications of low power wireless networking technology, particularly aimed at improving underground mine safety. Following an initial review, wireless technology was identified as having many desirable attributes as a modern underground data transmission medium. Wireless systems are mobile, flexible, and easily scalable. Installation time can be reduced and there is scope for rapid deployment of wireless sensor networks following an emergency incident such as a mine explosion or roof rock fall. Low power mesh technology, relating to the Zigbee and IEEE 802.15.4 LR-WPAN (low-rate wireless personal area network) standards, has been of particular interest within this research project. The new breed of LR-WPAN technology is specifically designed for low power, low data rate wireless sensor applications. The mesh networking characteristics of the technology significantly increase network robustness and resilience. The self-healing, self-organising, multiple pathway redundancy, and highly scalable attributes of mesh networks are particularly advantageous for underground, or confined space, high-integrity safety and emergency applications. The study and potential use of this type of technology in an underground mine is a novel aspect of this thesis. The initial feasibility and review examined the current and future trends of modern underground data transmission systems, with particular focus on mine safety. The findings following the review determined the ideal requirements of an underground data transmission in terms of robustness, integrity, interoperability, survivability and flexibility; with wireless mesh networking meeting many of these requirements. This research has investigated underground wireless propagation characteristics at UHF and microwave frequencies in tunnels. This has involved examining electromagnetic (EM) waveguide theory, in particular the lossy dielectric tunnel waveguide model e.g. (Emslie et al., 1975 and Delogne, 1982). Extensive tests have been carried out in three different underground locations (railway tunnel, hard rock mine, coal mine test facility) using continuous wave (CW), or ‘pure’ transmission at 2.3GHz and 5.8GHz, along with a range of throughput performance tests using various wireless technologies: IEEE 802.11b, 802.11g, SuperG, SuperG (plus BeamFlex antennas), 802.11pre-n. 802.11draft-n, and Bluetooth. The results of these practical tests have been compared with the lossy dielectric tunnel waveguide model showing good agreement that tunnels will in fact enhance the EM propagation through the waveguide effect. Building on previous research during the last 30 years into high frequency underground radio transmission, this work presents a novel investigation into the performance of modern underground wireless technologies operating in underground mines and tunnels. 4 The feasibility and performance of low power wireless mesh networking technology, relating to Zigbee/IEEE 802.15.4, operating in various underground and confined space environments has been investigated through a series of practical tests in different locations including: a hard rock test mine, a coal mine and a fire training centre (confined space built infrastructure). The results of these tests are presented discussing the significant benefits in employing ‘mesh’ topologies in mines and tunnels. Following this, key applications were identified for potential development. Distributed smart sensor network e.g. environmental monitoring, machine diagnostics or remote telemetry, applications were developed to a proof-of-concept stage. A remote 3D surveying telemetry application was also developed in conjunction with the ‘RSV’ (remote surveying vehicle) project at CSM. Vital signs monitoring of personnel has also been examined, with tests carried out in conjunction with the London Fire Service. ‘Zonal location information’ was another key application identified using underground mesh wireless networks to provide active tracking of personnel and vehicles as a lower cost alternative to RFID. Careful consideration has also been given to potential future work, ranging from ‘mine friendly’ antennas, to a ‘hybrid Zigbee’, such as, optimised routing algorithms, and improved physical RF performance, specifically for high-integrity underground safety and emergency applications. Both the tests carried out and key safety applications investigated have been a novel contribution of this thesis. In summary, this thesis has contributed to furthering the knowledge within the field of subsurface electromagnetic wave propagation at UHF and microwave frequencies. Key characteristics and requirements of an underground critical safety data transmission system have been identified. Novel aspects of this work involved investigating the application of new wireless mesh technology for underground environments, and investigating the performance of modern wireless technologies in tunnels through practical tests and theoretical analysis. Finally, this thesis has proved that robust and survivable underground data transmission, along with associated mine safety applications, can feasibly be achieved using the low power wireless mesh networking technology. Robust underground wireless networking also has potential benefits for other industrial and public sectors including tunnelling, emergency services and transport

802.11s Wireless Mesh Network Visualization Application

Results of past experimentation at NASA Johnson Space Center showed that the IEEE 802.11s standard has better performance than the widely implemented alternative protocol B.A.T.M.A.N (Better Approach to Mobile Ad hoc Networking). 802.11s is now formally incorporated into the Wi- Fi 802.11-2012 standard, which specifies a hybrid wireless mesh networking protocol (HWMP). In order to quickly analyze changes to the routing algorithm and to support optimizing the mesh network behavior for our intended application a visualization tool was developed by modifying and integrating open source tools

A Zigbee Technology for Lighting Control Application

Zigbee is wireless communication technology and IEEE 802.15.4 standards for data communication. There are zigbee standards provides network security and application sup port services operating on top of the IEEE 802.15.4 medium access control and physical layer wireless standards and it employs a group of technologies to enable scalable, self - organizations,self - healing networks that can mange various data traffic pattern s. The Zigbee is low - cost, low - power consumption, wireless mesh networking standards and It is designed around low power consumption allowing batteries to essentially last forever. Zigbee is use for monitoring and control applications. This paper presents a zigbee device types, its traffic varities, stucture and use in home automation and the lighting control application

Decentralized Federated Learning Over Slotted ALOHA Wireless Mesh Networking

Federated Learning (FL) presents a mechanism to allow decentralized training for machine learning (ML) models inherently enabling privacy preservation. The classical FL is implemented as a client-server system, which is known as Centralised Federated Learning (CFL). There are challenges inherent in CFL since all participants need to interact with a central server resulting in a potential communication bottleneck and a single point of failure. In addition, it is difficult to have a central server in some scenarios due to the implementation cost and complexity. This study aims to use Decentralized Federated learning (DFL) without a central server through one-hop neighbours. Such collaboration depends on the dynamics of communication networks, e.g., the topology of the network, the MAC protocol, and both large-scale and small-scale fading on links. In this paper, we employ stochastic geometry to model these dynamics explicitly, allowing us to quantify the performance of the DFL. The core objective is to achieve better classification without sacrificing privacy while accommodating for networking dynamics. In this paper, we are interested in how such topologies impact the performance of ML when deployed in practice. The proposed system is trained on a well-known MINST dataset for benchmarking, which contains labelled data samples of 60K images each with a size $28\times 28$ pixels, and 1000 random samples of this MNIST dataset are assigned for each participant’ device. The participants’ devices implement a CNN model as a classifier model. To evaluate the performance of the model, a number of participants are randomly selected from the network. Due to randomness in the communication process, these participants interact with the random number of nodes in the neighbourhood to exchange model parameters which are subsequently used to update the participants’ individual models. These participants connected successfully with a varying number of neighbours to exchange parameters and update their global models. The results show that the classification prediction system was able to achieve higher than 95% accuracy using the three different model optimizers in the training settings (i.e., SGD, ADAM, and RMSprop optimizers). Consequently, the DFL over mesh networking shows more flexibility in IoT systems, which reduces the communication cost and increases the convergence speed which can outperform CFL

Implementasi Teknologi Wireless Mesh Untuk Jaringan Komunikasi Data Pada Wireless Weather Station

To wider the coverage area of a weather sensor and to be always connected in realtime manner with other sensor, we proposed the enhancement of WWS communication data using Multipoint to Multipoint link which is Wireless Mesh Networking. From previous research has resulted a communication data between server and weather sensor using Point to Point link. Wireless mesh as one of variant innovation from WLANs technology offers a unique solution because it could be a replacement or enhancement for the established wireless network to be more effective and efficient. It has a wider coverage area without neglect of security factor and mobility. The result of this research is a Wireless Weather Station system which has been integrated with Mesh Network technology

Impact of Docker Container Virtualization On Wireless Mesh Network by Using Software-Defined Network

In today’s advanced digital world era, it is extremely difficult for small enterprises or organizations to merge traditional or legacy computer network devices/equipment and wireless mesh networking devices with the latest digital computer network technology with respect to the expense of buying and maintaining expensive branded networking devices. However, today, by applying the neatly Software-defined networking, the OpenFlow protocol along with virtualization such as docker containers, which is a pack of their specific libraries, configured files, and software, provides advantages over proprietary or branded computer networking devices with respect to purchasing expenditure, operational expenditure, and improved performance in computer networking. Redistribution of routing protocol is very essential when using various autonomous systems in wireless mesh networks. Docker containers of frr and quagga give an edge over traditional or branded physical router devices, some docker containers are used as wired and wireless hosts/clients in the wireless mesh network. The novel idea used in this paper is on how to use the different software-defined controllers (Ryu and Pox controller) in a docker containerized wireless mesh network to analyse with respect to packet transfer, jitter in transmission, minimum delay in transmission, maximum delay in transmission, the average delay in transmission,  delay standard deviation bit-rate, send packets,  average packets drop, dropped packets along-with average loss-burst size in Mininet Wi-Fi testbed at the different scenario and the result shows that by using the docker container virtualization along with software-defined network two different controllers improves the performance and optimize the wireless mesh network. In addition, it shows that by using containerization and virtualization, capital expenditure and operational expenditure can be reduced in designing and developing wireless mesh network topologies.&nbsp