RECOMMENDATION ITU-R P.533-7 - HF propagation prediction method* ANNEX 1 - CONTENTS 1 Introduction 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 3.6 The path operational MUF 4 E-layer maximum screening frequency ( fs) 5 Median sky-wave field strength 5.1 Paths up to 7 000 km 5.2 Paths longer than 9 000 km 5.3 Paths between 7 000 and 9 000 km 6 Median available receiver power 7 Monthly median signal-to-noise ratio 8 Sky-wave field strength, available receiver signal power and signal-to-noise ratios for other percentages ... 9 Lowest usable frequency (LUF) 10 Basic circuit reliability (BCR)