CONTENTS

Propagation data and prediction methods required for the design of terrestrial line-of-sight systems     3
Policy on Intellectual Property Right (IPR)     ii
RECOMMENDATION  ITU-R  P.530-13     1
Propagation data and prediction methods required for the design of terrestrial line-of-sight systems     1
Scope     1
Annex  1     1
1 Introduction  1
2 Propagation loss  2
        2.1     Attenuation due to atmospheric gases  3
        2.2 Diffraction fading  3
                  2.2.1     Diffraction loss dependence on path clearance  3
                  2.2.2 Planning criteria for path clearance  4
        2.3     Fading and enhancement due to multipath and related mechanisms  6
                  2.3.1 Method for small percentages of time  7
                  2.3.2 Method for all percentages of time  8
                  2.3.3 Prediction method for enhancement 10
                  2.3.4     Conversion from average worst month to average annual distributions  12
                  2.3.5 Conversion from average worst month to shorter worst periods of time  12
                  2.3.6     Prediction of non-selective outage (see Note 1) 13
                  2.3.7 Occurrence of simultaneous fading on multi-hop links  13
        2.4     Attenuation due to hydrometeors  13
                  2.4.1     Long-term statistics of rain attenuation  13
                  2.4.2 Combined method for rain and wet snow   14
                  2.4.3 Frequency scaling of long-term statistics of rain attenuation  17
                  2.4.4 Polarization scaling of long-term statistics of rain attenuation  17
                  2.4.5 Statistics of event duration and number of events  17
                  2.4.6 Rain attenuation in multiple hop networks  18
                  2.4.7 Prediction of outage due to precipitation  22
3 Variation in angle-of-arrival/launch  22
4 Reduction of cross-polar discrimination (XPD) 23
        4.1 Prediction of XPD outage due to clear-air effects  23
        4.2 Prediction of XPD outage due to precipitation effects  24
                  4.2.1 XPD statistics during precipitation conditions  24
                  4.2.2 Step-by-step procedure for predicting outage due to precipitation effects  25
5 Distortion due to propagation effects  25
        5.1 Prediction of outage in unprotected digital systems  26
6 Techniques for alleviating the effects of multipath propagation  27
        6.1 Techniques without diversity  27
                  6.1.1 Increase of path inclination  27
                  6.1.2 Reduction of effect of surface reflections  27
                  6.1.3 Reduction of path clearance  38
        6.2 Diversity techniques  38
                  6.2.1 Antenna spacing in space diversity systems  39
                  6.2.2 Angular spacing in angle-diversity and combined space/angle-diversity systems     41
                  6.2.3 Frequency separation in frequency diversity systems  41
                  6.2.4 Space-diversity improvement in narrow-band systems  43
                  6.2.5 Diversity techniques in digital systems  43
7 Prediction of total outage  47
8 Propagation aspects of bringing-into-service  47
Appendix  1 to  Annex  1  Method for determining the geoclimatic factor, K, from measured overland fading data     48