Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from where the Guidelines for Implementation of the Common Patent Policy for ITUT/ITUR/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at ) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication , 2013 ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU.
3 Antenna heights, h1 and h2 If the value of h1 or h2 coincides with one of the heights for which curves are provided, the required transmission loss values may be obtained directly from the plotted curves or the associated tabulations. Otherwise the required transmission loss should be interpolated from transmission losses obtained from two curves using: dB (5) where: h1, h2 : the antenna heights above mean sea level for which the prediction is required (m) hinf : the nearest nominal effective height below h1 or 2 hsup : the nearest nominal effective height above h1 or 2 Linf : transmission loss value for hinf at the required distance Lsup : transmission loss value for hsup at the required distance. 4 Interpolation of transmission loss as a function of distance Unless d coincides with one of the distances given in the tabulated values, the transmission loss, should be linearly interpolated for the logarithm of the distance using: dB (6) where: d : distance for which the prediction is required (km) dinf : nearest tabulation distance less than d dsup : nearest tabulation distance greater than d Linf : transmission loss value for dinf Lsup : transmission loss value for dsup. 5 Interpolation of transmission loss as a function of frequency If the frequency for the prediction is not one of the frequencies represented in the figures of this Recommendation or in the tabulated data, the required transmission loss should be calculated using: dB (7) where: f : frequency for which the prediction is required (MHz) finf : lower nominal frequency fsup : higher nominal frequency Linf : transmission loss value for finf Lsup : transmission loss value for fsup. 6 Interpolation of transmission loss as a function of percentage time Transmission loss values for a given percentage of time should be calculated by interpolation using:
dB (8) where: t : percentage time for which the prediction is required tinf : lower nominal percentage time tsup : upper nominal percentage time Qt = Qi (t/100) Qinf = Qi (tinf /100) Qsup = Qi (tsup /100) Linf : transmission loss value for time percentage tinf Lsup : transmission loss value for time percentage tsup where Qi (x) is the inverse complementary cumulative normal distribution function described in § 7. 7 An approximation to the inverse complementary cumulative normal distribution function The following approximation to the inverse complementary cumulative normal distribution function, Qi (x), is for 0.01 ≤ x ≤ 0.99: if x ≤ 0.5 (9a) if x > 0.5 (9b) where: (9c) (9d) C0 = 2.515517 C1 = 0.802853 C2 = 0.010328 D1 = 1.432788 D2 = 0.189269 D3 = 0.001308 Values by the above equations are given in Table 1. TABLE 1 Approximate inverse complementary cumulative normal distribution values q% Qi (q/100) q% Qi (q/100) q% Qi (q/100) q% Qi (q/100) 1 2.327 26 0.643 51 –0.025 76 –0.706 2 2.054 27 0.612 52 –0.050 77 –0.739 3 1.881 28 0.582 53 –0.075 78 –0.772