Rain Attenuation Estimation and Modeling for Terrestrial Microwave and Millimetric Band in Ethiopia
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Date
2022-01
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Addis Ababa University
Abstract
Researchers and network designers had been encouraged to have a look at communication structures that
perform at microwave and millimeter-wave bands for high speed, and dependable wi-fi communication
structures. Typically since of blockage within the lower frequency range and expanding demand for
huge transmission capacity and excessive channel capability. but, the reliability of radio communication
frameworks at the better operation frequency variety may be encouraged by means of different climatic
components. precipitation is the major cause of impairment at higher frequency band. Rain attenuation
is the prevailing figure within the way loss variety over 7 GHz and 10 GHz in tropical climates causes
weakening within the transmitted signal and decrease of the link accessibility. In microwave design rain
attenuation parameter using local data in Ethiopian context stays unstudied. Be that as it may, due to
the stochastic nature of the rain , it is require for exact propagation estimation due to the reality that
over-prediction comes about in expensive over-design, while, under-prediction can result within the lack
of quality of the frameworks.
In this paper, long-term rainfall measurements spanning a maximum of 10 years data collected from
Ethiopia National Meteorology Agency (ENMA) are obtained for 60 locations and received signal level
measurement from Ethio Telecom, to develop rain rate for radio link availabilities between 99% and
99.999% and rain attenuation maps for wireless radio links using Matlab and ArcGIS® software tools
and Excel and matlab. The research work has presented a model of 1-minute integration time rain fall
rate statistics of different locations in Ethiopia based on as much information as it was possible to gather
locally. The shortcoming of some widely used rain rate prediction approaches in relation to Ethiopia’s
climate has been shown. Hence, a new improved rain rate integration time conversion method, based on
1-minute rain rate data from a specific location, Jimma, has been used with good results. New R0.01
value for Jimma, Bahirdar, Dubti and others rest country in Ethiopia were calculated.
In addition, particular attenuation (dB/km) for both horizontal and vertical polarization is decided
as proposed by Worldwide Telecommunication Union (ITU) proposals at chosen frequencies for the
arranging of remote systems.Comes about gotten from this approach consolidating both precipitation
rate zones and particular attenuation over Ethiopia are displayed as spatial contour maps representations
for different ranges of link accessibility. It’s conceived that these maps will work as a valuable asset for
speedy reference for future link plan estimates, for terrestrial and satellite systems over Ethiopia, East
Africa. A comparison look at is finished on those to be had rain attenuation models; The ITU-R model,
Crane international model, and also Moupfouma model at unique frequencies and propagation path
lengths upheld the exact 1-minute integration time rain rate surpassed at 0.01% of the time-averaged
over a length of 10 a long time for each geological area. As a result, the attenuation predicted by new
conversion model with ITU-R method has better attenuation estimation than other existing models. It
is possible see the clear difference from this result for this specific location.
Description
Keywords
Rain rate distribution, conversion factor, contour map, Prediction models, Rain attenuation