Fair Analysis: Making Apples-to-Apples Microwave Radio Comparisons February 24, Languages: English Within any industry, there exists a group that strongly believes electronic products are simply commodities. These customers want the best product for the best price that, in turn, delivers a highly reliable network. System gain of a radio TX power — Rx Threshold defines the radios performance expectations. It is important to obtain these from the MW vendors radio files and then to validate via product bench testing or if publically available, the regulators licensing database. When different users do analysis, one radio can show a better link availability than the other.
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This empirical model introduces a more precise model than the traditional models. For example, the combined e? Table I shows the average values, standard deviations and the r. This method assumes that an equivalent rain cell of uniform rainfall rate and length d 0 can model nonuniform itk-r rate along the propagation path. S, Da Silva Mello L.
This concept of an effective path length, to take into account the non-uniform profile of rain intensity along a given path in the prediction of the rain attenuation cumulative distribution on radio links, is presently used in attenuation prediction methods such as that p.
Recently, there has been extensive work being carried out in time series synthesizers to provide synthesized rain attenuation time series . A new rain attenuation conversion technique for tropical regions.
In the slant path prediction method, given in Rec. Recommend this journal email your librarian or administrator to recommend adding this journal to your organisations collection. As a starting point, the dependence of the reduction factor on link parameters was investigated, using experimental data from concurrent long-term measurements of point rainfall rate and rain attenuation in terrestrial links available in the ITU-R databanks .
Transmission analysis of a single hop for microwave link. The recommendation deals only with effects related to the wanted signal. Irjetempirical field strength model for terrestrial. Only data from beacon measurements not data from radiometer measurements with concurrent measurements of rainfall rate were considered.
Also, the slant path and terrestrial prediction methods are not consistent, as different expressions for the horizontal path reduction factor are used in each case.
This section also provides comparison between some experimental measurements and the predicted values. For the slant path case, the data used to test the prediction methods includes concurrent measurements of rainfall rate and rain attenuation in received satellite beacon signals, also available in the ITU-R databank , comprising a total of year-stations from 68 sites in 24 countries.
The dependence of the effective rainfall rate with the point rainfall rate, the slant path length the elevation angle and the rain height found in the experimental data is shown in Figs. Tests with terrestrial links The test results indicate that, for the terrestrial case, the proposed method provides a large improvement over the method currently recommended by the ITU-R.
From 12 to 13, there is a radical change in the expression of the geoclimatic K factor and the worst month probability of unavailability. It was found that rp decreases with the path length and the point rainfall rate, as depicted in Figs. Unified method for the prediction of rain attenuation in satellite and terrestrial links The method uses the same simplified model of equivalent rain cell that is the basis for the ITU-R rain attenuation prediction methods but, additionally, the concept of an effective rain rate is introduced.
Rain attenuation prediction model over terrestrial links in equatorial and tropical climates has been reported by several authors. For example a high roughness can reduce the K factor and consequently the outage probability. If the rainfall rate variation along a given path is known, the attenuation due to rainfall along the path may be calculated by integrating the specific attenuation over the path length. Based on these observations, and after a series of trials with different functions, the following expression was chosen to fit R eff.
Pathloss version 5 the program is intended for experienced telecommunications network designers and a knowledge of radio wave propagation is a prerequisite to using this program. Although the K-factor decreases signi? Pdf the effect of terrain roughness in the microwave.
The behavior of d eff with R, for different values of d, is shown in Fig. All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License. Trace of the wimax signal as a function of the frequency.
This result is consistent with the results published by  which are based on link statistics used in the de? Link Calculation To better understand the impact of these modi? Another important limitation is that, when tested against the experimental data now available, the terrestrial prediction method shows significant underestimation of the measured attenuations. The validation of each new revision is confronted to measurements data collected over the world and available in SG3 database.
Losses due to gases are accounted for as per the itu recommendation i. Related Posts
Pathloss version 5
Pathloss 5 - Link Design Display Antenna heights The antenna heights display now shows the Fresnel zones and earth radius factor as separate curves resulting in a more intuitive operation. The diffraction loss at the minimum expected value of K and a second user specified value of K can be displayed as the antenna heights are varied. Any combination of antenna heights can be analysed using either the main or diversity clearance criteria. A minimum clearance can now be specified as part of the clearance criteria.
ITU-R P.530-13 PDF
This empirical model introduces a more precise model than the traditional models. For example, the combined e? Table I shows the average values, standard deviations and the r. This method assumes that an equivalent rain cell of uniform rainfall rate and length d 0 can model nonuniform itk-r rate along the propagation path.
Tinyu PDF Me
Moogurisar The field of rainfall rate is inhomogeneous in space and time . Propagation data and prediction methods p. The concept of an effective rainfall rate was introduced, in order to ith-r path correction factors larger than the unity. A correction factor r p was calculated not only for 0. The empirical expression obtained for this effective rainfall rate in given by 5. Transmission analysis of a single hop for microwave link.