Signal and noise variability in high frequency skywave radio-service planning

Procedures existing under the auspices of the International Telecommunication Union for allocating frequency blocks to radio services and for the assignment of specific frequencies to individual radio operators are explained. The compatibility analysis undertaken by the International Frequency Registration Board at high frequencies to test for harmful interference is described and the technical standards used in this analysis are discussed. Work in progress within the International Radio Consultative Committee in preparation for a forthcoming World Administrative Radio Conference on High Frequency Broadcasting concerned with improved standards for field strength estimation, fading, protection ratio and minimum usable field strength is reviewed.