Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Has files: YesSubject: search.filters.subject.5G mobile communication systems

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    D2D communication based disaster response system under 5G networks : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy (PhD) in Computer and Electronics Engineering, Massey University, Auckland, New Zealand
    (Massey University, 2023-12-14) Ahmed, Shakil
    Many recent natural disasters such as tsunamis, hurricanes, volcanoes, earthquakes, etc. have led to the loss of billions of dollars, resources and human lives. These catastrophic disasters have attracted the researchers’ attention onto the significant damage to communication infrastructure. Further, communication within the first 72 hours after a disaster is critical to get help from rescuers. The advancement of wireless communication technologies, especially mobile devices and technologies, could help improve emergency communication systems. The next generation of mobile networks and technologies such as Device to Device (D2D) communication, the Internet of Things (IoT), Blockchain, and Big Data, can play significant roles in overcoming the drawbacks of the current disaster management system for data analysis and decision making. Next-generation cellular 5G and 6G network will provide several complex services for mobile phones and other communication devices. To integrate those services, the 5G cellular network will have the capabilities to handle the significant volume of data rate and the capacity to handle traffic congestion compared with the 4G or 3G cellular network. D2D communication technology, one of the major technologies in the 5G network, has the capability to exchange a high volume of traffic data directly between User Equipment (UE) without additional control from the Base Station(BS). D2D communication is used with other cell tiers in the 5G heterogeneous network (HetNet). Thus, the devices can form a cluster and cooperate with each other. As a result, the system tremendously increases network capacity as devices inside the cluster reuse the same spectrum or use an unlicensed spectrum. It will help to reduce the network’s traffic load and achieve significant throughput. D2D communication also has the ability to increase area spectral efficiency, reduce device power consumption, outage probabilities and improve network coverage. All of these characteristics are vital parameters for public safety and emergency communication applications. IoT paradigm is another promising technology with exciting features such as heterogeneity, interoperability, and flexibility. IoT has the capability to handle vast amounts of data. This huge amount of data creates Data security and data storage problems. Though, there are many technologies used to overcome the problem of validating data authenticity and data storage. Out of them, the Blockchain system is one of the emerging technologies which provides intrinsic data security. In addition, Big data technology provides data storage, modification, process, visualisation and representation in an efficient and easily understandable format. This feature is essential for disaster applications because it requires quickly collecting and processing vast amounts of data for a prompt response. Therefore, the main focus of this research work is exploring and utilising these emerging technologies (D2D, IoT, Big Data and Blockchain) and validating them with mathematical modelling for developing a disaster response system. This thesis proposes a disaster response framework by integrating the emerging technologies to overcome the problem of data communication, data security, data analysis and visualisation. Mathematical analysis and simulation models for multiple disaster sizes were developed based on D2D communication system. The result shows significant improvement in the disaster framework performance. The Quality of Services (QoS) is calculated for different scales of disaster impact. Approximately 40% disaster-affected people can get 5-10 dB and approximately 20% users get 20-25 dB Signal to Interference and Noise Ratio (SINR) when 70% infrastructure is damaged by a disaster. The network coverage increased by 25% and the network lifetime increased by 8%-14%. The research helps to develop a resilient disaster communication network which minimises the communication gap between the disaster-affected people and the rescue team. It identified the areas according to the needs of the disaster-affected people and offered a viable solution for the government and other stakeholders to visualize the disaster’s effect. This helps to make quick decisions and responses for pre and post-disaster.
  • Thumbnail Image
    Item
    Integrated power amplifier and antenna-on-chip for 5G communication applications : thesis by publications presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering, Massey University, Auckland, New Zealand
    (Massey University, 2023) Ali, Syed Muhammad Ammar
    With the advent of 5G cellular networks, there is a crucial requirement for wireless hardware operable at microwave and millimeter-wave (mmW) frequencies. Two significant elements of wireless hardware are Power Amplifier (PA) and Antenna. An integrated power amplifier designed for 5G communications is expected to offer maximum performance in terms of efficiency, output power, and/or gain. An On-Chip Antenna design would require features like simple geometry, a small form factor, free from the risk of micro-fracture, and cost-effectiveness. Among different classes of PAs, the Class-F-1 amplifier is selected because it offers relatively better output power and efficiency. Different techniques are utilized in this work to enhance the performance parameters of the Class-F-1 PA, designed at the 5G-millimeterwave frequency of 38-GHz. In order to achieve high gain, a two-stage topology of Class-F-1 PA is employed. For the purpose of obtaining high output power, a stacking structure is established in the final stage of the two-stage topology. Class-F-1-based parasitic-aware harmonic-control loading is employed to improve the efficiency of the power amplifier. Therefore, a two-stage Class-F-1 power amplifier with a double-stacked configuration is designed and fabricated. GlobalFoundries 8HP 130nm SiGe-BiCMOS process technology is utilized for realizing the integrated mmW power amplifier. A Figure of Merit (FoM) is calculated for comparing the performance of the designed power amplifier with other mmW amplifiers reported in the literature. It is observed that the proposed two-stage double-stacked Class-F-1 PA shows comparatively the highest FoM (69.68) achieved so far in state-of-the-art silicon-based Class F/F-1 power amplifiers. Another integrated Class-F-1 power amplifier is proposed at a new unlicensed 5G-microwave frequency of 6-GHz. The PA is designed to achieve very high power-efficiency. The amplifier employs a “single-transistor” design in 65-nm standard CMOS process technology. The PA is loaded with a Class-F-1 harmonic-control network, employing a new parasitic-aware topology deduced using a novel iterative-algorithm. The proposed algorithm starts from a specific reference value and quickly converges towards the solution. A dual-purpose output-matching circuit is employed in the design. The output-matching circuit not only matches the output impedance to 50-Ω but also reinforces the Class-F-1 harmonic network in controlling the harmonics efficiently. The proposed amplifier offers a peak power-added-efficiency (PAE) of 47.8% which is one of the highest when compared with previously reported microwave/millimeterwave PAs in CMOS and SiGe process technologies. Besides power-amplifiers, another essential part of this research is On-Chip Antenna (OCA). As millimeterwave frequencies exhibit relatively smaller wavelengths, it becomes feasible to design an antenna on a microchip using standard CMOS processes. As compared to Off-Chip Antennas, the On-Chip Antennas offer a high level of integration with RF-front-end circuitry, as well as an external interconnect-free interface and low fabrication cost. An On-Chip Planar-Inverted-F Antenna (PIFA) in TSMC 180-nm CMOS is designed to radiate at the 5G-millimeterwave frequency of 38-GHz. A PIFA is selected because it offers simple geometry, small form factor, design flexibility, and robustness. An Ultra-Thick Metal (UTM) layer in 180-nm CMOS is utilized to implement the antenna structure on the chip. To achieve better radiation performance, the OCA is positioned close to the edge of the microchip. The measurements are conducted after placing the fabricated OCA over a 3D-printed plastic-slab to minimize the reflections from the metallic-chuck of the probe-station. The fabricated OCA delivered an antenna-gain of 0.7-dBi at the millimeterwave center-frequency of 38-GHz.
  • Thumbnail Image
    Item
    Blockchain for secured IoT and D2D applications over 5G cellular networks : a thesis by publications presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer and Electronics Engineering, Massey University, Albany, New Zealand
    (Massey University, 2021) Honar Pajooh, Houshyar
    The Internet of things (IoT) is in continuous development with ever-growing popularity. It brings significant benefits through enabling humans and the physical world to interact using various technologies from small sensors to cloud computing. IoT devices and networks are appealing targets of various cyber attacks and can be hampered by malicious intervening attackers if the IoT is not appropriately protected. However, IoT security and privacy remain a major challenge due to characteristics of the IoT, such as heterogeneity, scalability, nature of the data, and operation in open environments. Moreover, many existing cloud-based solutions for IoT security rely on central remote servers over vulnerable Internet connections. The decentralized and distributed nature of blockchain technology has attracted significant attention as a suitable solution to tackle the security and privacy concerns of the IoT and device-to-device (D2D) communication. This thesis explores the possible adoption of blockchain technology to address the security and privacy challenges of the IoT under the 5G cellular system. This thesis makes four novel contributions. First, a Multi-layer Blockchain Security (MBS) model is proposed to protect IoT networks while simplifying the implementation of blockchain technology. The concept of clustering is utilized to facilitate multi-layer architecture deployment and increase scalability. The K-unknown clusters are formed within the IoT network by applying a hybrid Evolutionary Computation Algorithm using Simulated Annealing (SA) and Genetic Algorithms (GA) to structure the overlay nodes. The open-source Hyperledger Fabric (HLF) Blockchain platform is deployed for the proposed model development. Base stations adopt a global blockchain approach to communicate with each other securely. The quantitative arguments demonstrate that the proposed clustering algorithm performs well when compared to the earlier reported methods. The proposed lightweight blockchain model is also better suited to balance network latency and throughput compared to a traditional global blockchain. Next, a model is proposed to integrate IoT systems and blockchain by implementing the permissioned blockchain Hyperledger Fabric. The security of the edge computing devices is provided by employing a local authentication process. A lightweight mutual authentication and authorization solution is proposed to ensure the security of tiny IoT devices within the ecosystem. In addition, the proposed model provides traceability for the data generated by the IoT devices. The performance of the proposed model is validated with practical implementation by measuring performance metrics such as transaction throughput and latency, resource consumption, and network use. The results indicate that the proposed platform with the HLF implementation is promising for the security of resource-constrained IoT devices and is scalable for deployment in various IoT scenarios. Despite the increasing development of blockchain platforms, there is still no comprehensive method for adopting blockchain technology on IoT systems due to the blockchain's limited capability to process substantial transaction requests from a massive number of IoT devices. The Fabric comprises various components such as smart contracts, peers, endorsers, validators, committers, and Orderers. A comprehensive empirical model is proposed that measures HLF's performance and identifies potential performance bottlenecks to better meet blockchain-based IoT applications' requirements. The implementation of HLF on distributed large-scale IoT systems is proposed. The performance of the HLF is evaluated in terms of throughput, latency, network sizes, scalability, and the number of peers serviceable by the platform. The experimental results demonstrate that the proposed framework can provide a detailed and real-time performance evaluation of blockchain systems for large-scale IoT applications. The diversity and the sheer increase in the number of connected IoT devices have brought significant concerns about storing and protecting the large IoT data volume. Dependencies of the centralized server solution impose significant trust issues and make it vulnerable to security risks. A layer-based distributed data storage design and implementation of a blockchain-enabled large-scale IoT system is proposed to mitigate these challenges by using the HLF platform for distributed ledger solutions. The need for a centralized server and third-party auditor is eliminated by leveraging HLF peers who perform transaction verification and records audits in a big data system with the help of blockchain technology. The HLF blockchain facilitates storing the lightweight verification tags on the blockchain ledger. In contrast, the actual metadata is stored in the off-chain big data system to reduce the communication overheads and enhance data integrity. Finally, experiments are conducted to evaluate the performance of the proposed scheme in terms of throughput, latency, communication, and computation costs. The results indicate the feasibility of the proposed solution to retrieve and store the provenance of large-scale IoT data within the big data ecosystem using the HLF blockchain.