Browsing by Author "Usman, Ayinde Mohammed"

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    Assessment of Quality of Service of G.S.M. Networks in Ilorin Metropolis, Nigeria
    (Ahmadu Bello University, Kaduna Nigeria, 2020-06-30) SURAJUDEEN-BAKINDE, Nazmat Toyin; Adeniji, Kehinde Adetunji; Oyeleye, Sam Oloruntoba; Zakariyya, Sikiru Olayinka; Olayanju, Sunday Akinwale; Usman, Ayinde Mohammed
    Following the rollout of GSM services across Nigeria, the socio-economic landscape of the country has been positively altered. Its explosive growth has brought huge revenues to the operators, as well as the government and at the same time benefited the citizens in many ways. However, the principal developmental factors that has continued to mar these benefits is the aggressive complaints from GSM subscribers regarding the horrible Quality of Service (QoS) rendered by the GSM operators across the country. As the number of subscribers of GSM in Nigeria increased, congestion rates also increased and there has been a huge demand for a decent QoS in the country. In this study, three key performance indicators (KPI) parameters, call setup success rate (CSSR), received signal level (RSL) and call drop rate (CDR) were used in assessing the performance of two of the major GSM networks in Ilorin Metropolis of Nigeria, which have been tagged Network “A” and Network “B”. A and B monitored are far from providing reliable services to Nigerians. None of the networks in the study met the ≥ 98% CSSR required by the N.C.C. regulations, and none met the ≤ 2% CDR required by the N.C.C. regulations. The problems GSM operation encountered have been attributed to a number of challenges, with cited faults ranging from the Network providers, to regulatory agencies, and even to the Nigerian Government.
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    Development of A Direct Conductive Coupled Multi-Input Phase-Shifted Full-Bridge DC-DC Converter
    (School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor Bahru., 2020) Otuoze, Abdulrahaman; Ibrahim, Oladimeji; Yahaya, Nor Zaihar; Saad, Nordin; Hassan, M.D.; Afolayan, Mubarak Akorede; Madugu, Ibrahim; Usman, Ayinde Mohammed
    Hybrid energy system is commonly employed in renewable energy systems to bridge the gap of non-availability of one power source with the others. In this work, a direct conductive electrical circuit connection topology for realizing multiple power source synchronization in the hybrid energy system is proposed. A three-input power sources integration scheme was realized via forward-conduction bidirectional blocking switch which serves input to the common power conversion stage of phase-shifted full-bridge DC-DC converter to boost the synchronized common bus voltage. An average current sharing controller is designed for the multiple parallel power sources to ensure equal load sharing when all the sources operates on the same and different voltage level. In this study, a 3-kW rating hybrid energy system was implemented in Simulink environment to investigate the multiple source integrator, the current sharing capability, and the common power conversion stage performance. The system ensured equal load sharing, allowed individual and simultaneous power transfer from the multiple sources to the load under the same and different operating supply voltage level.