General Principles of Narrow Band Direct Printing (NBDP) and Telex Over Radio (TOR) systems. Ability to Use Maritime NBDP and TOR Equipment in Practice
Note: Narrow Band Direct Printing (NBDP) telegraphy is a means of communication whereby a printed or hard' copy is available at each communications terminal. NBDP is also known as radiotelex, and is used for NAVTEX broadcasts.
Ships at sea may communicate with shore-based telex machines by calling coast radio stations on frequencies specifically allocated for NBDP use. NAVTEX is a system utilising NBDP in the shore-ship direction only, for the broadcast of, for example, MSI.
Whenever possible automatic procedures should be used ...