Investigation on Need for Specific Propagation Model for Specific Environment Based on Different Terrain Characteristics

Abstract

Owing to their speed of excution as well as their limited reliance on detailed knowledge of the terrain characteristics of the service environments, empirical propagation models have enjoyed general acceptability in the wireless communication research community. However, recent industrial observations show that no single propagation model can best fit all the radio service environments, which led to the hypothesis of specific models for specific environments. In order to scientifically verify this hypothesis, the study presented in this paper investigated the performance of the free space propagation loss (FSPL) model in two different radio environments characterised with different types of obstructions. The investigation was conducted through field strength distribution measurement of two broadcasting radio stations transmitting at 96.5 MHz and 102.3 MHz. The field strength measurement data obtained were analysed. The result of the analysis shows gross disparity between the measured path losses and calculated path losses using FSPL model. The disparity thus necessitates the modification of the FSPL model in order to develop each propagation model for each of the two radio stations employed and their environment. The developed models were then evaluated to ascertain their performances relative to the FSPL model. The performance evaluation results show that the predictions of the developed propagation models vary for each of the two environments. Furthermore, the comparative performance evaluation result of the developed models with similar studies in the literature shows that the developed models perform favourably. The overall result from the developed models confirms the hypothesis that each location requires a specific propagation model for proper radio wave design and quality of signal transmission and reception.
 ABSTRAK: Kelebihan yang ada pada kelajuan perlaksanaannya dan juga kurang pergantungannya pada butiran terperinci ciri-ciri khusus bentuk rupa bumi di persekitaran servisnya, model penyebaran empirik telah diterima umum dalam komuniti kajian komunikasi tanpa wayar. Walau bagaimanapun, pemerhatian industri terkini menunjukkan tidak ada sebarang model penyebaran yang sesuai bagi semua keadaan servis radio, ini menghala kepada hipotesis keperluan model tertentu pada keadaan servis tertentu. Bagi menentusahkan secara saintifik hipotesis ini, kajian yang dibentangkan dalam kertas ini mengkaji tentang prestasi model kehilangan penyebaran pada ruang bebas (FSPL) dalam dua persekitaran radio berlainan melalui beberapa jenis halangan berbeza. Kajian telah dijalankan ke atas dua stesen radio penyiaran pada frekuensi 96.5 MHz dan 102.3 MHz melalui ukuran sebaran ruang keupayaan. Data ukuran ruang keupayaan telah diperoleh dan dianalisa. Keputusan analisis menunjukkan keputusan tidak seragam yang melampau antara ukuran kehilangan laluan dan pada kiraan model FSPL. Ketidaksamaan ini memungkinkan keperluan mengubah model FSPL bagi membangunkan model penyebaran pada setiap dua radio stesen yang digunakan dan persekitarannya. Model yang dibangunkan ini kemudiannya dinilai bagi mengesahkan prestasinya dengan model FSPL. Keputusan penilaian menunjukkan perbezaan pada jangkaan model penyebaran bagi setiap dua keadaan. Tambahan, keputusan perbandingan model yang dibangunkan dalam karya ini adalah serupa seperti kajian lain yang berkaitan. Secara keseluruhannya model yang dibangunkan ini mengesahkan hipotesis bahawa setiap lokasi memerlukan model penyebaran bagi rekaan gelombang radio yang sesuai dan juga kualiti signal penyebaran dan penerimaan.

Assessment and Development of Path Loss Propagation Model for Ikire Metropolis, Nigeria

“…This indicates that the path loss prediction potential of the developed path loss model for this study performs better than that of COST 231-Hata as its path loss prediction value is lower than that of COST 231-Hata. This result buttresses the finding in [8], which was verified scientifically in [9] that specific path loss model ought to be developed for specific location for better quality signal reception of broadcasting signal in each location.…”

“…5 revealed that the exponent of the predictions made by COST 231-Hata model is given mathematically as; The brief review of these three propagation models reveals that availability of correction factors are essential for direct application of model(s) developed in a particular terrain to be used in another terrain(s). The review also buttresses the findings in [8,9] that there is need for different empirical models for different types of radio signals at different locations under different conditions or terrains. Furthermore, the brief review buttresses the finding reported in [25] that a radio propagation model, which gives an acceptable prediction in one location might not be suitable in another location.…”

“…Radiowave propagation as defined in [9] is the behaviour of radiowaves when they are propagated or transmitted from one point on the earth to another point or into various parts of the atmosphere. It is also defined as the way and manner radiowave travels between the transmitter and receiver, which is generally done either directly from one point to another or following the curvature of the earth or becoming trapped in the atmosphere and travelling longer distance or refracting off the ionosphere back to earth.…”

“…It is also defined as the way and manner radiowave travels between the transmitter and receiver, which is generally done either directly from one point to another or following the curvature of the earth or becoming trapped in the atmosphere and travelling longer distance or refracting off the ionosphere back to earth. Irrespective of the propagation mode, radiowave propagation is always affected by different phenomenon [9,[12][13][14][15][16][17] leading to path loss or signal degradation.…”

“…Thus, according to [6], radio propagation model is an emprical mathematical formulation for the classification of radiowave propagation as function of distance, frequency and other conditions that regulates the behaviour of radio signal in a given transmission channel. Since individual wireless communication system encounters different terrain, obstructions and atmospheric conditions based on where they are propagated, it is not sufficient to formulate a single mathematical equation to model all factors in all environs and terrains [8,9]. Hence, in order to improve the strength of the transmitted signal in wireless channel, there is need to evaluate the path loss introduced by a terrain to adequately compensate for the signal power loss during signal transmission.…”