This paper presents measurement and evaluation of radiation power density emitted from mobile cellular base stations in Abuja and it’s environ. Forty (40) mobile base stations with ten (10) each from AIRTEL, ETISALAT, GLO and MTN located in areas with high population were randomly examined across Abuja. Broadband analysis method was employed in the measurement of the radiation power density. The results obtained shows that most of the base stations recorded lower radiation power density below the safety standard value of 4.5watt/m2 , 22.5 watt/m2 for 900MHz frequency though few base stations recorded above standard value: GLO-BS02, GLO-BS03 and MTN-BS02 recorded 59.02 mW/m2, 39.76 mW/m2 and 46.70 mW/m2 respectively. The result also revealed that as distance increases, the mean power density reduces. This is to said that human exposure to radio frequency radiation have less or no health hazard at distance far away from the mobile cellular base station.

This paper presents the design and construction of a smart-home automation system using nodeMCU and Google assistant. The device consist of Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module that contains all clock generators, shift registers and data buffers necessary to perform an input or output serial data transfer independently of the device program execution. The NodeMCU (ESP8266) Wi-fi Shield connected the microcontroller to the provided Wi-fi network. The Arduino and MPLAB Programming Interface with the help of PICKit3 were used to run the code on PIC16F877A. Home appliances were controlled via a web page created using IFTTT for the voice command and the Blynk app for controlling hardware remotely and also display sensor data. IFTTT is a simple to use internet service that easily enables IoT devices to GET and POST data. The device was constructed based on low cost and reliable home controlled monitoring system for accessing and controlling electronics appliances remotely using any Smart phone with access to Google assistance or Computer web application. The device was test under different electronics appliances with different voltage capacities and was found efficient. Therefore, this device when used is capable of improving the living standard at home, reduces human effort, save energy and time thus make homes have sufficient automation.

The 12 to 18 GHz frequency bands are commonly deployed for mobile network metropolitan microwave radio links using small antennas and low transmit power to deliver high channel capacities. Jos Plateau region with the blend of tropical and temperate climate is characterized with high severe rain impairment on terrestrial links operating at frequencies above 10 GHz, for mobile network backhaul system remaining a big challenge in the design of a microwave radio link. Therefore, this study presents the performance analysis of the impact of rain attenuated signal on mobile cellular terrestrial links in Jos under clear sky and rain condition. The cell site locations were divided in two clusters of Jos lowland and Jos highland. Drive test tools, radio local monitor terminal (LMT) and Davis weather station were employed over radio links interconnecting live 2G/3G nodal network, for the measurement of the mean value of one minute rainfall rates and the corresponding rain-induced signal. The results obtained revealed that more budget provision was obtained by the study calculation in over 60% of the study centers. More so, when the study fade margin estimation was put to test, up to 4.27 Mbps download speed was achieved, the speed almost as high as the highest speed, 4.29 Mbps recorded under the clear sky for ITU-R. More so, as low as 0.7% packet loss was recorded against the study link margin budget under same rain condition causing over 62.3% for PLA010 in Jos lowland cluster. Also, instances of slight under-budgeting were observed in highland clusters PLA064 and PLA025 as 35.01 dB and 34.99 dB respectively when tested with the Study calculated values.

This study was aimed at analyzing the effect of temperature and relative humidity on downlink satellite communication systems over Warri, in Delta State, Nigeria. The data used in this study were temperature, relative humidity and radio signal strength (RSS) obtained from the Nigeria Meteorological Agency (NIMET) for the years 2018 and 2019 respectively, both from January to December. Davis Vantage Vue weather station was used to measure the temperature and relative humidity while Spectrum analyzer was used to measure RSS. Both instruments were set to function simultaneously. Results obtained for all the months shows that the level of radio signal strength under the influence of temperature is higher either RSS ≥ 65% compare to that of relative humidity either RSS ≤ 64% which also fluctuate the level of RSS on daily basis, throughout the years under review. It was realized that there is a variation in the refractive index of the medium through which the radiowaves are propagated, due to the variations in the temperature and relative humidity, these adversely affect the received signals strength over the downlink satellite communication systems. The results obtained from this study will serve as guide for link budget design for satellite communication operators within the study. Therefore, similar study of this kind is recommended in other locations experiencing severe weather conditions.

This paper presents the measurement and prediction of received signal level and path loss through vegetation. Results were estimated under free space, single tree, and vegetation conditions which revealed that the presence of isolated trees along a radio path can affect signal propagation leading to reduction in signal strength (attenuation). The attenuation was found to be dependent on many factors and parameters of the trees e.g. Geometry of measurement, (either trunk or canopy path), state of trees foliation, frequency, canopy thickness among others. In the measured data, high loss values were recorded at canopy geometry which is due to high presence of interacting and attenuating elements at the canopy. Also, high variation in Received signal strength (RSS) was noted at canopy geometry. However, the trend shows variation from path to path. The main factor is the density of tree parameters along the chosen path. Depending on the density of tree parameters along the chosen path, the depth dependence may be extremely slow as seen in the measure data. With this evidence, for radio communication inside woodlands or forests, localizing the two nodes inside the vegetation will certainly give overall best performance in terms of signal impairment. The propagation mechanism in each case are the same at the antenna geometries used following the trend of signal decay. Different transmit antenna inclination angles were used and this has not shown any significant contribution to the excess loss. However, antenna height with respect to the trees canopy showed significant contribution to the excess loss. This information will be useful to network planning engineers in link budget estimation.