Various research studies have been carried out by different researchers on the behaviour of radio wave within different environment under different environmental and geographical conditions. The models derived are specific for the respective environment. To validate the model, field measurements were carried out at different locations within Epe town and its environs. The measurements system consist of live radio base stations transmitting at 900MHz and 1800MHz. Downlink signal strength level data were collected using drive test exercise consisting of test mobile phones, TEMS investigating software, MapInfo and Google earth. The respective path loss values were estimated and compared with existing model like OkumuraHata model for rural, suburban and urban areas. The result indicated an appreciable consistency with the empirical models except for rural areas.

Line-of-sight (LOS) attenuation at 7.2GHz was measured in Lagos (6 o 26N, 3 o 52E) for twelve months (Aug '08-July'09) using one of the Nigerian Telecommunications radio signal. The measurement was carried out with the intent of highlighting microwave signal attenuation in Harmattan and rain weather conditions. The results are presented in terms of mean signal level, received signal level and fog attenuation, rain attenuation, multipath fading, free space loss and link availability. The observed attenuation values due to Harmattan (fog) and rain attenuation was calculated (using Altshuler's model). Also, the statistics of fade distribution show fast fading of longer duration of the order of 16 to 39 fades per hour during this period (Harmattan) and 24 to 48 fades per hour during the period of rain. This shows that microwave LOS link in this region and regions with similar climatic characteristics are prone to signal degradation as well as fading in the Harmattan and rain season.

Various propagation models have been described by various research experiments in recent times. The results of each experiment depend largely on the environmental conditions under which each experiment was carried out. This model can be applied under similar environmental conditions. This research attempts to investigate the effectiveness of the Okumura-Hata model in a typical Nigerian terrain. A GSM base station operation at 900MHz band was used for the experiment in a typical sub-urban area within the Northern part of Nigeria. The field measurement results were compared with Okumura-Hata model for rural and sub-urban area. The results obtained indicate the least variation with Okumura-Hata model for sub-urban areas.

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This study is aimed at presenting a report on the quality of service of network optimization and evaluation of key performance indices provided by GSM operators. This is expressed in terms of the ability to establish and maintain call connections, call retention, handover, inter and intra network call set-up. Test points within the service areas were randomly selected and in each of these locations, series of measurements were taken. Conclusively, a model of service quality and a set of dimensions for comparative evaluation, which could provide useful directions to regulators and service providers, are presented. Also, we shall briefly analyse the outgoing call quality to suit this purpose.

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This paper presents path loss measurement and modeling for Lagos state dense-urban (DU), urban (UR), suburban (SU) and non-urban (NU) G.S.M environments. It was carried out with data collection through drive testing using TEMS software in the chosen environments Lagos-Island(DU), Surulere (UR), Lekki-Oniru (SU), Agbede-Ikorodu (NU), over a distance of 0.5-10Km from Base station (BS) to Mobile station (MS) with measurement taken at 0.5Km intervals for a period of 52 weeks. Relative parameters like Rxlev, RSSI, Path loss were measured in all areas of investigation under 2G and 3G frequencies of operation and twelve (12) different sites location were covered and analysed. COST 231-Hata model was used as reference model for path loss calculation of field data, this was further adjusted to develop optimized models (tagged OMODEEN models) for path loss prediction in all environments of study, which shows results within 6dB acceptable range, hence recommended for modeling in these environs and other similar G.S.M environments.