ITU-R REPORT M.1161 PDF

Introduction and background

The facility for inserting the public switched network number in a Digital Selective Calling (DSC) call (see Recommendation 493, Annex I § 8.2.3) has enabled an automatic (direct-dial) telephone system to be introduced in the VHF band, using the existing Appendix 18 working channels, based on the operational procedures which are described in draft Recommendation 689.

This report examines the MF/HF situation and proposes that such an automatic system (with some modifications compared to the VHF system) may indeed be introduced on MF/HF frequencies.