| The main aim of radio network planning is to provide a cost-effective solution for the radio network in terms of coverage, capacity and quality, and varies from region to region depending upon the dominating factor, which could be capacity or coverage. Coverage of a cell is dependent upon the area covered by the signal while the distance travelled by the signal is dependent upon radio propagation characteristics in the given area i.e. the operating frequency and the propagation environments. For different environments, which vary from region to region, the transmission path between the transmitter and the receiver can vary from a simple line of sight(LOS) to a one that is severely obstructed by man-made structure such as buildings, and/or other natural terrains like mountains and foliage.The first step in the process of a new radio system plan/design is to determine base station arrangement and a frequency plan, both of which are dependent on environmental characteristics and a reliable prediction of radio wave propagation. One of the most important characteristics of the propagation environment is the path loss which tells us how much a transmitter needs to radiate to service a given region. It depends on frequency, base station(BS) and mobile station(MS) antennas heights, distance and topography. An accurate estimation of the path losses provides a good basis for a proper selection of base station locations, determination of its coverage and optimization as well as a proper determination of the frequency plan.Propagation prediction models are used to describe and predict the way a radio signal changes when traveling from the transmitter to the receiver, i.e. to predict path losses and determine the received signal strength at the end of the link. Thus they are the foundation for channel modeling and a major factor in communication network planning. They are categorized as Empirical models, semi-deterministic and deterministic models based on whether they derived from empirical measurements or EM wave equations or a combination of the two.In this paper, the performance and applications of empirical and semi-deterministic models for macrocell systems are analyzed to determine their suitability for path losses prediction for macrocellular mobile networks in Kenyan environments. In total, five outdoor Propagation Models and three outdoor-to-indoor propagation models are analyzed for three operating frequencies which are 900 MHz, 1900 MHz and 2300 MHz. The Outdoor models analyzed are Hata model, COST231-Hata model, SUI model, COST231-WI model and WINNER model. In outdoor-to-door scenario, Turkmani et al. model, Berg et al. model and Okamoto et al. model are analyzed.The simulation results of comparison of these models show that the COST231-WI model has the lowest path loss in both urban and suburban areas for all the three frequencies considered. For Rural areas, the Hata has the least path loss compared to the other models for 900 MHz. For 1900 MHz and 2300 MHz, the LOS of the WINNER model has the least for shorter distance while for longer distance the Hata model has least path loss. For outdoor-to-indoor, the Okamoto et al. penetration prediction method was found to be more reliable than the other models. |
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