Photovoltaic modules behave extraordinarily by transforming part of the visible spectrum into electrical energy, and their efficiencies are affected by the nature of radiation (light) reaching them. When light strikes a photovoltaic cell, this light may go through the cell without been absorbed if it is too energetic or if the light possesses low energy it will be absorbed by the cell and cause the electrons to twist and vibrate in their bonds without dislodging them, hence causing the cell to heat up which ultimately leads to a decrease in its overall efficiency. This study is aimed to investigate how photovoltaics respond to different wavelengths of light. For the study to achieve its aim, colour filters were used to ensure that only a particular wavelength of light reaches the photovoltaic module at a time. In the process of collecting data from the solar panel, the solar panel was placed horizontally flat on a platform one meter above sea level facing the sun. Data was first obtained from the solar panel without the filters and after that with the filters placed one at a time and data collected accordingly. The amount of solar power and solar flux anytime a different colour filter was placed on the solar panel were measured. Among the coloured filter used yellow produced the highest efficiency, while blue produced the least efficiency. However, the solar panel was still more efficient when exposed to the natural spectrum.

Every radio frequency (RF) design, after its implantation, should be regularly evaluated. The kernel of this article is to evaluate the performance of four GSM networks, taking its received signal quality (RxQual) into consideration. A total of 10501, 10140, 10415 and 10690 RxQual measurements were obtained for MTN, 9mobile, Airtel and Globacom network. These generated data were subjected to statistical analysis in the form of bar charts, quality plots and calculations of measures of central tendency and dispersion. Result shows that 78.43%, 92.18%, 90.68% and 86.93% of the drive test route for MTN, 9mobile, Airtel and Globacom network had good signal quality and met with the Nigerian telecommunication regulatory benchmark of at least 4dB for RxQual. It is therefore deduced that in terms of RxQual, 9mobile was the best GSM network, followed by Airtel network, Globacom network and then MTN network. The result provided in this article will help mobile network operators to improve signal quality, ensure improved network coverage and increase network capacity in the future.

For appropriate regulation and quality assurance, continuous monitoring of cellular network services is necessary. A drive test measurement was carried out in Calabar, to investigate four UMTS networks, taking cognizance of Call Setup Success Rate (CSSR), Drop Call Rate (DCR), Handover Success Rate (HOSR), Call Setup Time (CST), Received Signal Code Power (RSCP) and Signal-to-Interference Ratio (Ec/Io). The collected data was analyzed and the obtained results was compared with the performance threshold levels of the Nigerian Communication Commission (NCC). The four networks had excellent CST, with MTN leading, followed by Airtel, then 9mobile and Globacom. For CSSR, Airtel had excellent performance, as there was no blocked call. This was followed by MTN and Globacom. 9mobile failed in CSSR as it was below the NCC recommended benchmark. There was no drop call in Airtel, MTN and 9mobile, but Globacom’s performance was below the recommended threshold for dropped calls. For HOSR, the four networks showed excellent performance as they were able to handover calls between cells, as recommended by NCC. Considering the RSCP, the four networks displayed excellent services as subscribers experienced good voice and data services. However, the four networks had poor coverage quality (Ec/Io), the worst, being displayed by MTN. This shows that the equipment capability of the networks is low. The network operators are advised to monitor their services often, so as to optimize their networks for a better Quality of Service (QoS).

To evaluate the reliability and quality of signal of UMTS radio access technology of three cellular networks (MTN, 9mobile and Airtel network) over two cities in Nigeria, an intensive drive test measurement was conducted, taking into consideration, signal-to-interference ratio (Ec/Io) as the key performance indicator under study. A total of 10958, 11075 and 11109 Ec/Io measurements were obtained for MTN, 9mobile and Airtel network. These measured data were subjected to statistical analysis in the form of bar charts, quality plots and calculations of measures of central tendency and dispersion. Result shows that 59.64%, 50.45% and 17.02% of the drive test route for Airtel, 9mobile and MTN network had good signal quality and met with the Nigerian telecommunication regulatory benchmark of at least -9dB for Ec/Io. Also, 40.36%, 49.55% and 82.98% of the drive test area for Airtel, 9mobile and MTN network fell below the regulatory benchmark and subscribers in this region experienced dropped calls, blocked calls, handover failures and degraded signal quality due to interference. Airtel network was adjudged the best network while the worst network was MTN network. The result provided by this article will help radio network engineers operating in Calabar South and Calabar Municipality, to efficiently reuse limited frequencies, avoid interferences, optimize handover and adjust transmitted power level. The mobile network operators are advised to build new base stations and visit the existing ones regularly for optimization.

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