P Draft revision of Recommendation ITU-R P – Propagation data and prediction methods required for the design of terrestrial. ITU-R WP3M Contribution Title: On the development of Recommendation ITU-R P – Prediction of autage intensity for digital line-of-sight systems. ITU-R P 4. 1. 0. – B. D. Ad. – 1. 0. 1. – – GHz 2. % ke.. (dB) h/F1. B.: D.: GHz 6,5. 4/3 = ke. Ad.: (2) h.
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International Journal of Satellite Communications, Int. 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.350-13 Recommendation ITU-R 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.
For space Pw frequency and space diversity 2 receivers vs. 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 .
Theoretical Prediction curve is an upper bound which is validated during the link measurement duration 2 years. 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.
In this time percentage range, the China’s method provides slightly better results than the other methods. 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.
Sincethirteen revisions were proposed. 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? Peiro, “Simple rain attenuation prediction technique for terrestrial radio links”, Elect. 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?
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.