Browsing by Author "Akinwumi, A."

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Analysis of Attenuation Due to Atmospheric Gases Prediction Models at Ota, Nigeria
(Science and Technology: Developments and Applications Vol. 7, 2025) Akinwumi, A.; Omotosho, T.; Usikalu, M.; Adewusi, M.; Ometan, O.; Emetere, M.
The theory explaining the interaction between molecules and radiation of gases in telecommunication ascertained the fact that microwave signals experience significant attenuation that can appreciably degrade the quality of signal transmissions. Millimeter and sub-millimeter wave signals experience scattering and absorption while propagating through the atmosphere. The demand for satellite services is rapidly increasing on a daily basis. One of the major concerns for satellite telecommunication designers is the impacts of gas attenuation on earthspace path links, most importantly in tropical areas. This research has been directed at the analysis and comparison of gas attenuation prediction models at Covenant University, Ota, southwest Nigeria (Lat: 6.7 o N, Long: 3.23o E). Gas attenuation data were collected from the spectrum analyzer and Davis automatic weather station for a period of five years (April 2012- December 2016) from Astra 2E/2F/2G Satellite link set at an elevation angle of 59.9o on 12.245 GHz. The monthly gas attenuation was analyzed and compared with existing gas attenuation prediction models that could provide a guide to microwave propagation engineers in the tropical region. The results suggest that even during clear-sky, gas attenuation still poses a threat to the design of satellite communication on the earth-space path. The results also suggest that even during clear-sky, gas attenuation still poses a threat to the design of satellite communication on the earth-space path. Likewise, the same pattern was observed from 2013 to 2016 where Salonen’s model was reported as the lowest model and Liebe’s model gave the highest value. Therefore, the ITU-R model may be more accurate for modelling gas attenuation for the region. Hence, the statistics provided in this work will help engineers in planning and designing good telecommunication systems in the tropical region.
Effects of Aerosol Scattering Attenuation on Free-Space Optical Link Performance in Owerri, Southeast, Nigeria
(Science and Technology: Developments and Applications Vol. 8,, 2025) Akinwumi, A.; Ayo-Akanbi, O.; Omotosho, T. V; Arijaje, T; Ometan, T.; Adewusi, O.
High-speed, point-to-point data transmission through laser beams across terrestrial networks is sometimes referred to as "Free-Space Optics" (FSO). Multimedia applications including social networks, OTT platforms, video conferencing, and multimedia streaming are driving up the demand for data rates and channel bandwidth, which has led to a telecommunications bottleneck. In spite of the several benefits of using free-space optical (FSO) communication systems as complementary platforms for next-generation networks, the existence of atmospheric disturbances such as fog and scintillations are key sources of signal impairment that affect system performance. Thus, it is crucial to learn about the specific weather patterns of the areas where FSO lines will be installed. The purpose of this work is to estimate the availability performance of FSO lines broadcasting at both 850 nm and 1550 nm by performing a statistical analysis of meteorological visibility data gathered for Owerri in Nigeria over a 21-year period (2000-2021). The results show that the visibility during the most common fog events in Owerri is 100 meters. The probabilities of encountering and exceeding the scattering attenuations associated with Owerri's most common fog event are 0.0002 and 0.0229, respectively. This research could be expanded in the future by exploring the effects of varying localized climatic conditions on the many forms of optical signals, such as plane, spherical, and Gaussian beam waves. This would aid in the modelling of different forms of attenuation for deployment sites of FSO or hybrid FSO systems.