CONTENTS

Policy on Intellectual Property Right (IPR)
Annex 1  Table of Contents
1 Introduction
PART 1  Frequency availability
2 Location of control points
3 Basic and operational maximum usable frequencies
        3.1 Basic maximum usable frequencies
        3.2 E-layer critical frequency (foE)
        3.3 E-layer basic MUF
        3.4 F2-layer characteristics
        3.5 F2-layer basic MUF
                  3.5.1 Lowest-order mode
                  3.5.2 Higher-order modes (paths up to 9 000 km)
        3.6 Within the month probability of ionospheric propagation support
        3.7 The path operational MUF
4 E-layer maximum screening frequency (f_s)
PART 2  Median sky-wave field strength
5 Median sky-wave field strength
        5.1 Elevation angle
        5.2 Paths up to 9 000 km
                  5.2.1 Modes considered
                  5.2.2 Field strength determination
        5.3     Paths longer than 7 000 km
                  5.3.1 Determination of the f_M
                  5.3.2     Determination of the f_L
                  5.3.3 Estimation of the field strength E_tl
        5.4 Paths between 7 000 and 9 000 km
6 Median available receiver power
PART 3  The prediction of system performance
7 Monthly median signal-to-noise ratio
8 Sky-wave field strength, available receiver signal power and signal-to‑noise ratios for other percentages of time
9 Lowest usable frequency (LUF)
10 Basic circuit reliability (BCR)
       10.1 The reliability of analogue modulated systems
       10.2 The reliability of digitally modulated systems, taking account of the time and frequency spreading of the received signal
                  10.2.1 System parameters
                  10.2.2 Time delay
                  10.2.3 Reliability prediction procedure
For path lengths up to 9 000 km:
For path lengths beyond 9 000 km:
       10.3 Equatorial scattering
Attachment 1  to Annex 1  A model for equatorial scattering of HF signals