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The previous point of view of worst case leads to an elevation angle of −1.87-degree and an attenuation of 170.77 dB. With this kind of attenuation, every system would be unusable! It was found also for this case that with the nominal elevation angle, the distance of the tangent point to ground is 5.84 km; that of the worst case is 2.69 km.
In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. [1] Path loss is a major component in the analysis and design of the link budget of a telecommunication system. This term is commonly used in wireless communications and signal propagation.
It is possible to extrapolate the cumulative attenuation distribution at a given location by using the CCIR interpolation formula: [12] A p = A 001 0.12 p −(0.546 − 0.0043 log 10 p). where A p is the attenuation in dB exceeded for a p percentage of the time and A 001 is the attenuation exceeded for 0.01% of the time.
Introduction to RF Propagation, John S. Seybold, 2005, John Wiley and Sons. Radio Propagation in Cellular Networks, N. Blaunstein, 2000, Artech House; The Mobile Radio Propagation Channel, J. D. Parsons, 2000, Wiley; Mark A. Weissberger (1982). "An initial critical summary of models for predicting the attenuation of radio waves by trees".
Attenuation decreases the intensity of electromagnetic radiation due to absorption or scattering of photons. Attenuation does not include the decrease in intensity due to inverse-square law geometric spreading. Therefore, calculation of the total change in intensity involves both the inverse-square law and an estimation of attenuation over the ...
Friis' original idea behind his transmission formula was to dispense with the usage of directivity or gain when describing antenna performance. In their place is the descriptor of antenna capture area as one of two important parts of the transmission formula that characterizes the behavior of a free-space radio circuit.
The statistical estimates or attenuation variables of this prediction model are: I) Situation variability (Ys); II) Time variability (Yt); II) Location variability (YL). The reference attenuation (W) is determined as a function of the distance, attenuation variables and an urban factor for an area or point-to-point.