CONTENTS

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