The Okumura model is a Radio propagation model that was built using the data collected in the city of Tokyo, Japan. The model is ideal for using in cities with many urban structures but not many tall blocking structures. The model served as a base for the Hata Model. Okumura model was built into three modes. The ones for urban, suburban and open areas.
in the validation of employed path loss models, including the urban formula of the Hata model and the Walfish-Ikegami model, two fundamental path loss models for urban areas for the cellular frequency band. For this case study, the path loss models have been employed outside their suggested frequency range.
The results shown in the paper are for propagation path loss considering Okumura–Hata model and Walfisch–Ikegami model in the implementation of a digital cellular system in the region on the ... models are available to predict path loss over different types of terrain . The models dealt with are applicable for GSM bands (900 MHz, 1800 MHz). 2.1 Hata Model Hata Model  is an empirical formulation of graphical path loss data provided by Okumura model. The Hata model gives prediction of the median path loss. Wireless Communication Fundamentals David Tipper Associate Professor Department of Information Science and Telecommunications University of Pittsburgh Telcom 2700 Slides 2 Telcom 2700 2 Wireless Networks – Wireless Wide Area Networks (WWANs) • Cellular Networks : – GSM, cdmaone (IS-95), UMTS, cdma2000 EVDO • Satellite Networks: Path loss models Egli's model is appropriate for macrocellular systems, with carrier frequencies above 30 MHz. Hata's model has been derived from curves plotted by Okumura. This formula assumes that the target is in the far-field of the transmitting element or array. In the near-field, the free-space path loss formula is not valid and can result in a loss smaller than 0 dB, equivalent to a signal gain. For this reason, the loss is set to 0 dB for range values R ≤ λ/4π.
Path Loss Models n Path Loss Models are commonly used to estimate link budgets, cell sizes and shapes, capacity, handoff criteria etc. n “Macroscopic” or “large scale” variation of RSS n Path loss = loss in signal strength as a function of distance n Terrain dependent (urban, rural, mountainous), ground reflection, diffraction, etc. COST 231 Hata Model equation, the modified model performs better with a RMSE of 5.1dB. The modified COST 231 Hata Model is therefore, recommended for path loss prediction across the region in question. References Casaravilla J., Dutra G., Pignataro N. & Acuna J. “Propagation Model for Small Macro cells in Urban Areas” Path Loss Models n Path Loss Models are commonly used to estimate link budgets, cell sizes and shapes, capacity, handoff criteria etc. n “Macroscopic” or “large scale” variation of RSS n Path loss = loss in signal strength as a function of distance n Terrain dependent (urban, rural, mountainous), ground reflection, diffraction, etc. The coefficient will vary according to the type of terrain either water, wet ground, desert etc. For this the path loss equation is given by, Lpe = 40log10 (d) - 20log10 (h1) - 20log10 (h2 ) (7) Here „ d‟ is the path length in meter h1 and h2 are the antenna heights at the base station and the mobile,respectively.