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Faculty of Engineering and Built Environment

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Author: search.filters.author.Molefe, Mlungisi

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Now showing 1 - 6 of 6
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    A resources allocation scheme for joint optical wireless transport networks
    (IEEE, 2023-08-03) Molefe, Mlungisi; Sibiya, Khulekani; Nleya, Bakhe
    As the future of networking dives into a new era of connecting every single physical device into the internet termed Internet of Things (loT), this significantly means a rapid increase in the number of online connected devices, which leads to more bandwidth hungry and data consuming devices. The fifth generation (5G) of mobile communication has been deployed already in multiple countries, therefore researchers have migrated their focus to the sixth generation (6G) of mobile communication to cater for extensive coverage and massive number of loT devices. A promising architecture and technology to cope with massive number of online devices and extensive coverage is a joint optical wireless transport network which offers comparably ultra-high systems capacity and extremely low latency while maintaining an improved quality of service. Furthermore, an optical wireless transport network can accommodate high speed mobility for frequently moving end user devices which is essential for 6G. In this paper our focus is to explore and propose an ultimate optical wireless transport network architecture scheme that will cater for loT as well as networks beyond 5G. We thus propose an innovative Optical-Backhaul and Wireless Access (OBWA) network architecture as a favorable solution for future networks. We further present a joint channel and route allocation (JCRA) scheme for achieving optimal quality of experience. Performance evaluation of the proposed JCRA scheme for OBW A network architecture show a significant improvement in the network throughput as well as the network end-to-end delay despite varying load traffic or varying flow channels.
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    Resources allocation for hybrid cloud-edge computing in 5G network slicing
    (TELKOM, 2023-09-01) Molefe, Mlungisi; Sibiya, Khulekani; Nleya, Bakhe; Smuts, Martin; Taute, Anton
    In typical heterogeneous networks such as 5G and beyond, innovative technologies such as edge computing and network slicing can enhance overall network performance in terms of handling critical mission services as they often require extremely low latencies. Notably, network slicing facilitates the provisioning of virtual slices with different characteristics to serve different end-user requirements. The Network operator achieves this goal by utilizing the already existing physical wireless network resource. Current resource provisioning schemes suffer inadequacies in scalability and flexibility Thus to support both Cloud and Edge Computing in 5G and beyond networking, the work herein proposes a novel low latency scheme that affords dynamic and intelligent allocation of multi-dimensional resources. It bases on a Hybrid Cloud-edge Network Slicing (HCENS) architecture on leveraging both Cloud and Edge Computing The proposed scheme creates a flexible, scalable as well as energy efficient resource provisioning. Its architecture comprises both centralized units (CUs) and distributed units (DUs). These provide storage, that in turn enhances function partitioning for various network slices. Several agent-based simulations scenarios are carried out in evaluating the efficacy of the proposed scheme. Obtained analytical and simulation results indicate drastic reductions in network latencies for critical mission end user services. This couples with reductions in storage requirements.
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    An energy efficient resource provisioning scheme for joint all photonic and wireless networks
    (IEEE, 2022-08-04) Molefe, Mlungisi; Nleya, Bakhe
    Flexible joint all photonic and wireless transport networks are a promising backbone network technological solution to accommodate the various dynamic bandwidth natured applications. In this paper, we mitigate methods aimed at maximizing available resources in a joint-photonic and wireless transport network in an energy-efficient manner. In so doing, we take into account challenges posed by transmission impairments as they tend to degrade signals and reduce their optical reach. We thus propose a state-of-the-art and innovative network architecture that can efficiently process a large amount of data. This architecture is designed to cater for bandwidth-hungry and bandwidth-dynamic applications and services. We further propose a load aware energy efficient resource optimization scheme using LERA algorithm, which couples with related service reconfiguration functions to maximize higher spectral efficiencies and minimal blocking in both optical and wireless sections of the composite network. Performance analysis shows that the proposed architectural scheme based on the LERA algorithm outperforms traditional benchmark techniques in achieving minimal blocking while efficiently maximizing spectral utilization compared to legacy benchmark approaches. Hence this scheme drastically enhances the utilization of the available resources and the overall network throughput.
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    An energy efficient resources allocation scheme for flexible translucent optical transport networks
    (Psychology and Education, 2021-03-02) Nleya, Bakhe; Molefe, Mlungisi; Chidzonga, Richard
    The present study attempts to explore how academic streams and learning styles play role in the preferences of coping strategies among prospective teachers. A quantitative approach was selected to explore the relationship. A survey was conducted with 300 prospective teachers (150 of science stream and 150 of humanities stream). A multi-stage random sampling technique was used to collect relevant information. Research instrument to measure coping strategies was developed by the researcher himself and Learning Style Inventory (LSI) by Ritu Dangwal & Sugata Mitra, 1997 was used to measure learning styles of prospective teachers. Statistical techniques i.e. mean, S.D., multivariate ANOVA were applied. Results revealed an essential significant effect of academic streams and learning styles on preference of coping strategies among prospective teachers. It is recommended that teacher training institutions should establish guidance or counseling centers to provide counseling to prospective teachers regarding coping skills and learning styles
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    An energy-efficient impairment-aware routing algorithm for optical transport networks
    (IEEE, 2021-03) Molefe, Mlungisi; Nleya, Bakhe; Chidzonga, R.; Bopape, Lebogang; Sibiya, K.
    Flexible Translucent optical Transport networks have the capability to provision multiple data rate demands much more efficiently than the traditional wavelength routed optical backbone networks. By design, in order to suffice the signal reach constraint, traditional optical networks also include several repeaters that are located sparsely along each signal path so as to facilitate successful end-to end transmission of those lightpath connection signals that otherwise would exceed the optical reach. The presence of physical impairments coupled with the inclusion of repeaters that facilitate signal amplification, timing and refreshing means more overall operational power requirements. Thus, energy efficient operation of flexible Translucent Optical Transport Networks is quite crucial. Thus, in this paper we propose a combined physical impairments-aware as well as energy-efficient available network resources allocation algorithm that bases on path availability, considering the impact of energy consumption minimization versus quality of transmission (QoT). We consider the impact of physical impairments in the formulation of the algorithm. We carry out simulation validations of the proposed algorithm which generally indicate to an improvement of energy efficiency as well as other key network resources utilization.
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    Architectural considerations and resource allocation in energy efficient networking
    (2022-09-29) Molefe, Mlungisi; Nleya, Bakhe
    Word-wide data traffic is continuously surging, triggered mainly by the emergence of Internet-of-Things (IoT)’s services and Fog-Cloud computing-based applications. This calls for existing optical and wireless-based network infrastructures to upgrade capacity accordingly to meet required massive bandwidth demands to accommodate the ever-surging data traffic volumes. However, continuously elevating the resource requirements in terms of bandwidth provisioning implies increasing the number of en-ergy-consuming network elements, which will increase overall operational expendi-tures and carbon footprint due to extra power generation. Carbon emissions contribute significantly to global warming. To avert this, it has become necessary to promote en-ergy-efficient networking. For that reason, it necessitated an emphasis on energy effi-ciency in the design, operation, and planning of transport networks. The current dense wavelength division multiplexing (DWDM) based optical transport network architectures operate with fixed-grid employing fixed data rates. So, making this rigid approach to capacity allocation leads to inefficiencies in both spectrum allo-cation and energy usage. Flexible (or elastic) optical transport networks with flexible-grid were proposed to improve bandwidth provisioning efficiencies. Such networks support adaptive line rates and OFDM-based optical transmission, thus, this will lead to lesser network elements deployed and, consequently an improvement in energy ef-ficiency. Similarly, wireless networks, whose data traffic is mostly derived from de-vice-to-device (D2D) communication and heterogeneous 5G cellular networks (HET-NETs) have since made tremendous strides to further enhance bandwidth by way of overlaying multiple types of low power small cells in a high-power macro cell. They afford more opportunities to explore the potential cognition and cooperation diversi-ties to improve spectral efficiency. Thus in this work, we focus on both architectural design and operation of wireless and optical transport networks coupled with resource allocation. A model joint all photonic and wireless transport network architecture framework is proposed and analyzed. The architecture’s performance in servicing high-capacity mobile back-haul and front-haul traffic and real-time services support is evaluated by both analytical and simulation approaches. Various routing and switching scenarios are considered. Overall, results demonstrate that elasticity allocation of resources (bandwidth) can vastly improve the network performance in terms of spectral efficiency, reduced locking probability, and enhanced end-to-end network throughput.