Modeling of Radio Waves Transmission in Buildings Located Around Niger Delta Urban Microcell Environment Using ?Ray Tracing Techniques?

The fundamental sculpt of radio waves propagation is the radiation of radio waves from a point-source electromagnetic energy to different directions. In practice, this radiated energy varies and diminishes in strength as it propagates from the point-source to the receiver. The level of attenuation of this radio wave can be determined by many factors. Researchers on urban wireless microcells networks, had very often, focused on measurements and modeling of reflected and diffracted rays from corners of structures and their exterior walls. In some cases the structures in questions were treated as opaque to signal propagating under terrestrial mobile frequency range. The attenuation capacity of these structures forms the basis of this study. Quasi-two-dimensional ray-based model was employed during the study. The transmitting and receiving antennae heights were erected at elevation levels not above the top of an average roof, while the base station antenna was assumed to be at the same height as the mobile station to enable the transmitted rays to propagate in a horizontal plane. This was anchored on the theory that transmitted e-m waves have uniform distribution as it propagated through different layers of the building. The attenuation coefficients of other obstructions in the periphery of the environment were not considered. Furthermore, only the exterior building coordinates were assumed to be known. X () =, which has a pulse-like shape, to estimate the complex impulse response (CIR) of the channel under examination. According to the transmission mode of the building penetration model, the building transmission loss was given as Lt = b dm - 20log|T (r1) | - 20log|T (r2) | dB The attenuation factors, for this study was higher than the specific attenuation factors evaluated for 2GHz, signal penetration for buildings. The values ranged between 0.3dB/m and 0.6dB/m, while propagation loss ranged from 20 dB to 40 dB. Previous research works have posted values more than 40dB. The variance observed here can be attributed to how dense the urban location is, and the focus on high rain forest zone in the Niger Delta region of Nigeria. The study shall be very useful during the planning stages of microcellular networks, routing configuration-guide and network performance management. The limitation of the study is the inability to determine the attenuation coefficient per building.