Papers by Author: F.O. Edeko

Abstract: This work presents a VSAT based approach for extending mobile communication access to rural communities in developing countries using VSAT and satellite technology. The rural areas are clustered into village community cells with each cluster being served by a non regenerative bidirectional repeater system. The telecommunication technology of choice is the GSM standard. Traffic from the rural areas is collated together at the access point which serves as an interface between the village community cells and the satellite. The access points perform a frequency translation moving the signal from the GSM band to the satellite band at the transmitter and vice versa at the receiver. The system maximizes the advantage of satellite communication technology over other types in linking remote areas to urban centers that are geographically far apart. The satellite then links the village cell to the operator’s network via a dedicated BTS in the urban area. The system has the advantage of being modular, scalable and solar powered due to the low traffic from rural areas.

Abstract: The numerical solution of the partial differential equation (PDE) of the received signal strength from fixed transmitting stations as derived from Maxwell’s wave equation is presented in this paper. The received signal strength level (RSSL) at a defined distance from a source point (base transceiver station) was simulated for two real environments described as Sites 1 and 2. The values of RSSL were taken at different nodes and at different radial directions away from the source point using the Finite Element Method (FEM) tool of the MATLAB package. The hexagonal geometry with no describing function was assumed for the cell. A 3-D model of the power received versus distance was obtained, and the numerical solution of the model presented. The numerical results obtained from the 3-D model were compared with the results of the drive test conducted in Sites 1 and 2 for functional GSM radio networks in the areas. The suitability of the method was justified for the two sites with a 5.55dB standard deviation of error for network A in Site 1 and 8.36dB and 3.40dB standard deviations of error for networks A and B respectively for Site 2.

Abstract: The success of wireless local area networks (WLANs) has led to an intense interest among wireless engineers in understanding and predicting radio propagation characteristics within buildings. This paper present radio signal propagation measurement and modeling at 2.4GHz, within a building in the Faculty of Engineering, University of Benin. A base station built around SENAO access point, and a PA24 flat panel directional antenna of 19dBi gain and 17.50 beam-widths was setup for the experimentation. Signals were monitored from the fixed BS using LINKSYS, and NET STUMBLER version 4.0 software run on a Laptop. In this report, the effect of multi-path and delay spread was not considered. The result of the investigation revealed a significant attenuation of the radio signal within the small distance. A path loss exponent of 7.8 to 8.9 on the ground floor, and 2.9 to 5.2 for the 2nd floor were obtained for the period of investigation.

Abstract: This work investigates the microwave link degradation due to atmospheric conditions on the Akure-Owo Digital Microwave Link. Microwave line of sight measurements were carried out between January and December 2005 with a data acquisition software (PROCOMM PLUS SOFTWARE). The data collected were analyzed using MATLAB 7.0 SOFTWARE program to determine the months of the year that has the highest degradation due to atmospheric conditions and also the months of the year that has the highest bit error rates. The result showed that the months of January, June, July, August and September have the worst signal degradation of -0.97dbm, -2.0dbm, -3.97dbm, -3.97dbm, -1.97dbm. respectively. The result also showed that the bit error rates are good and acceptable throughout the months of the year. A model equation was developed to predict the signal strength received and the bit error rate in the microwave link investigated, when atmospheric conditions are taken into consideration. The results of the predicted model were validated by field data and the results obtained showed an error of -0.2% for the received signal level and zero error for the bit error rate which means that the developed model equations can be used to accurately predict the link degradation parameters.

Abstract: The incidence of car theft in Nigeria has grown to nearly epidemic proportion. On daily basis, the numbers of stolen cars reported over the media are on the increase. Alarms and other deterrents are not enough. There is actually little one can do to prevent a car from being stolen. However, with a Global System for Mobile communication (GSM) activated automobile demobilizer with identification capability one can virtually take control of the virtually impossible incidence and hence increase the possibility of car recovery. This paper is aimed at implementing a security device capable of safeguarding cars from theft as well as provides picture and audio information of the culprits in an attempt to steal the car. To realize this work, use was made of a GSM phone