ICT INFORMAL SECTOR JOBS AND SATISFACTION AMONG THE YOUTHS IN OSUN STATE, NIGERIA

The youths are the greatest assets of any nation. However in Nigeria, one of the vital socio-economic challenges in Nigeria is youth unemployment. In a quick reaction to this milieu, the informal sectors have been a veritable avenue to provide economic opportunities to the teaming youth. However, most past studies have focused on job satisfaction in the formal sector, while few have evaluated how informal sector jobs meets the entrepreneur needs, wants, or expectations – satisfaction, especially from the Information and Communication Technologies (ICT’s) angle. Against this background, the study examined ICT Informal Sector Jobs and Satisfaction among the Youths in Osun State, Nigeria. Institutional theory was adopted to give theoretical explanation to issues of interest. Data was gathered among 168 youths who were purposively selected for the study through questionnaire administration. Findings revealed that engagement in ICT informal sector jobs have positively influence youth job satisfaction. The study concluded that, though ICT informal sector jobs play a positive role in youths job satisfaction, however, those who venture into sale of phones and its accessories were more satisfied than others. As a result of this, this study suggests that governmental organisations, non- governmental organisation and other concern bodies should encourage Nigerian youths, through the provision of funds, to venture into ICT informal sector jobs, especially sale of phones and sale of phone accessories as they increase youth wellbeing, enhance nature of work and gives a positive feeling towards their jobs

Investigation of Low Clouds Attenuation on Earth Space Path for some West-Africa Stations

The study investigate the contribution of low clouds, to signal fade rate, at Ka band in the satellite communication links on earth-space path(s) to NigComSat 2, from three tropical locations in West Africa. Extracted cloud cover statistical data such as average cloud amount, average base height, and frequency of occurrence, were used to obtain the monthly variations and seasonal variations for Lagos (6.55o, 3.35o), Bouake (7.73o, -5.07o) and Bamako (12.53o, -7.95o). Cloud attenuation statistics were computed for each of the three stations for their respective uplink and downlink. The uplink and downlink attenuation ranges between about 0.2 to 1.6 dB and 0.1 to 0.8 dB respectively for Lagos; for Bouake between 0.005 to 0.035 dB and 0.003 to 0.016 dB respectively; finally, for Bamako between about 0.2 to 2 dB and about 0.1 to 1 dB respectively. The stations downlink attenuation sets of values are generally about twice their corresponding uplink attenuation values

Tropospheric Scintillation and its Impact on Earth- Space Satellite Communication in Nigeria

The study investigates the impact of tropospheric scintillation on fixed satellite communication link on earth-space path for frequencies between 10 and 50 GHz for 37 stations in Nigeria. Elevation angles of 5º, 55º which are typical look angles for links over the Atlantic Ocean region and Indian Ocean region, look angles to the Nigeria Communication Satellite was also considered. Meteorological climatic data retrieve from satellite such as; profiles of temperature, pressure, and relative humidity, were validated with the available ground data in Nigeria. These data were reprocessed to derive radio propagation input parameters, such as; water vapour density integrated water vapour content and radio refractivity. Secondly, the International Telecommunication Union Propagation model (ITU-P 618, 2009) was used to estimate tropospheric scintillation for time unavailability between 0.01 to 10% in an average year. The result shows that scintillation fade depth is between 4.0 to 19.0 dB and 0.2 to 1.3 dB at 5º and 55º elevation angles respectively. For links to NigComsat scintillation fade depth is between 0.05 to 1.26 dB for all the 37-locations. The results will help in designing, planning and quick integration and expansion of satellite telecommunication services in the six regions of Nigeria

ATMOSPHERIC GASES ATTENUATION IN WEST AFRICA

Atmospheric gases variations were evaluated to have major effect on Ku-band and above at 0.01 % unavailability of an average year on both uplink and down link. The International Telecommunication Union Radio Propagation Recommendation (ITU-RP 676, 2012) data bank was used for the computation of gaseous attenuation for West Africa. Monthly and yearly mean of temperature, pressure and relative humidity were used as input parameters obtained from ITU-R study group 3 data base. The results presented on contour map show that total atmospheric absorption signal fade attenuation values at C, Ku, Ka and V bands is between 0.015 to 0.09 dB, 0.04 to 0.9 dB, 0.04 to 1.4 dB and 0.2 to 3.2 dB respectively for both uplink and downlink frequencies. Generally, consistent signal absorption due to Oxygen and water vapour are higher in the western region than southern part of West Africa

Four Year Cloud Attenuation Study in a Tropical Station

The paper present four year results of Cloud attenuation measurements carried out at Covenant University, Ota, Nigeria. The links operate at frequency of 12.245 GHz and the cumulative distribution function for monthly Cloud attenuation have been estimated from the 4-year measured spectrum analyser data. The result of the visually measured Cloud and Satellite Cloud cover data are presented. The monthly variability shows that the highest cloud attenuation at the station occur in August, reaching a maximum of 3.96 dB for 0.01% of time; which corresponding to an average cloud cover of 89.86% and 75.36% by ground and satellite data respectively of which Nimbostratus (Ns) is average of 29.1%. The lowest cloud attenuation at the station occur in September, with a value of 2.5 dB for 0.01% of time; corresponding to an average cloud cover of 90.3% and 77.26% by ground and satellite data respectively, of which Nimbostratus (Ns) is average of 28.9%

Earth-Space Rain Attenuation Prediction: Its Impact at Ku, Ka and V-band Over Some Equatorial Stations

Attenuation due to rain predictive models have been used to calculate the impact of rainfall on satellite communication for six stations in Malaysia. The impact of rainfall is very important for designing a modern satellite system for heavy rainfall climatic regions like Malaysia, with large annual rainfall accumulation exceeding 3000 mm and rainfall rate exceeding 150 mm/h at Ku (12/14 GHz), Ka (20/30 GHz) and V (40/50 GHz) bands. The present result shows that the avalibility of link for 99.99% at the three bands for uplink and downlink to Malaysian Communication Satellite (MEASAT-3a) is not practicable. The results suggest link availability of 99.9% for Ku-uplink and Ka downlink, while 99% for Ka uplink and 99% for V band uplink and downlink due to high annual rainfall rates for most of the stations. The overall result shows that the impact of heavy rainfall on satellite communication will be more severe in the Eastern part than the Western of Malaysia

Analysis of non-rainy attenuation on earth-space path in Ota, Southwest Nigeria

Propagation effects due to atmospheric gases and tropospheric scintillation requires accurate modelling in the design of satellite communication systems. The combination of the two attenuation phenomena was observed within the period of August 2014 to December 2015. The result of this paper presents the on-going observation and data analysis of non-rainy attenuation on earth-space path in Ota, Southwest Nigeria. Results of clear-sky attenuation vary between 0 dBm and 4.85 dBm in January and February 2015 respectively. While a value of 4.23 dBm and 4.75 dBm were observed in October 2014 and 2015 respectively. The results will be useful for satellite communication system design and will be submitted to ITU-R Study group 3 Databank

Proposed Model for the Estimation of Rain Attenuation: At Ku-Band at Ota, a Tropical Location

This study proposes a model for calculating rain attenuation on earth-space path carried out in Covenant University, Ota, Nigeria, a tropical location. The beacon signals from a geostationary satellite - ASTRA 28°E (2E/2F/2G) was monitored, recorded and analysed using a spectrum analyzer operating at frequencies of 12.245 GHz. Rain rates at the station of the antenna receivers were also logged and analysed. The rainfall rate cumulative distributions and the resultant rain attenuation are obtained and presented. The results obtained showed that the cumulative distribution of the measured rainfall rate is not in agreement with ITU-R prediction. Rainfall rate at 0.001 %, 0.01 %, 0.1 % and 1 % were fed into the existing Simple Attenuation Model (SAM) and corresponding rain attenuation were obtained. The measured rain attenuation from the beacon signal was compared with sixteen existing rain attenuation models in literature only SAM model was closed to the measured result at the location. SAM model overestimated and underestimated the rain attenuation for this location at some percentage of time. Hence, a modified SAM model is proposed using newly obtained specific attenuation coefficients. The proposed modified model is found to be close to the measured rain attenuation

Modeling of Cloud Attenuation on Earth - Space Path in Ota Southwest Nigeria

A new cloud attenuation model on earth-space path has been develop for a tropical station (6.7°N, 3.23°E) based on cloud cover, radiometric measurement and climatological data at the Covenant University in Ota. The collection of station data by a 7GHz spectrum analyzer for the total attenuation at elevation angle of 59.9° to Astra 2 satellites located at longitude 28.2°E. Automatic weather station parameters and daily visual clouds observation; as well as the acquisition of station radiosonde data were carried out. The station spectrum analyzer data between 2014 and 2017 were analyzed to obtain cloud attenuation contributions from the total attenuation measurement. The measured Cloud attenuation was compared with eight existing cloud attenuation models. Cloud attenuation at 12.245 GHz is 3.40 dB compare to 0.81 dB cloud attenuation predicted by ITU-RP 840 model, next is the Liebe's model, followed by Slobin model. A new developmental model was derived for the tropical station. The new cloud attenuation model was developed using the station radiosonde data from 1953-2011 for the computations of each cloud layer's liquid water content and specific attenuation coefficient. The cumulative distribution curves obtained was compared with each simulation distribution and the closest match to the station measured cumulative distribution is considered in the new cloud attenuation model for the station. The new model predicted 4.0 dB margins for clouds attenuation at 0.01% unavailability for the station. The study reveal cloud attenuation was under estimate by the eight existing cloud attenuation model for the tropical station

Year to year variation of rainfall rate and rainfall regime in Ota, southwest Nigeria for the year 2012 to 2015

The tropics is characterized to have convective type of rainfall which has high occurrence of rainfall compared to the temperate regions of the world. In this paper, the accumulation of rainfall in Ota, Southwest, Nigeria (6o 42 N, 3o 14 E) has been analysed to present the one-minute rainfall rate and the predominant type of rainfall. Four years’ data used for this study was taken using the Davis Wireless vantage Pro2 weather station at Covenant University, Ota, Ogun State. The data collected were used to analyse the one-minute rainfall rate and different types of rainfall predominant in this region. For the prediction and modelling of rain attenuation at microwave frequencies for a region like the Nigeria at various percentage of time, one-minute rainfall rate is required. Nigeria falls into the P zone of 114 mm/hr. as per International Telecommunication Union – Recommendation (ITU-R). The analysis carried out indicated that the measured yearly averaged maximum one-minute rainfall rate for 2012, 2013, 2014 and 2015 are 157.7 mm/h, 148.0 mm/h, 241.2 mm/h and 157.3 mm/h respectively. It also indicated that the drizzle type of rainfall is predominant in contrast to established fact that thunderstorm occurs more in the tropics