The Automatic Transmitter Identification System (ATIS) is a

marine VHF radio Marine VHF radio is a worldwide system of two way radio transceivers on ships and watercraft used for bidirectional voice communication from ship-to-ship, ship-to-shore (for example with harbormasters), and in certain circumstances ship-to-a ...

system used and mandated on navigable inland

waterway A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary b ...

s in Europe for identifying the ship or vessel that made a radio transmission. The identity of the vessel is sent digitally immediately after the ship's radio operator has finished talking and releases their transceiver's

push-to-talk Push-to-talk (PTT), also known as press-to-transmit, is a method of having conversations or talking on half-duplex communication lines, including two-way radio, using a momentary button to switch from voice reception mode to transmit mode. H ...

button. This contrasts to the Automatic identification system(AIS) used globally on ships that transmit continuously. A short post-transmission message is sent by the radio with the vessel identity and is in the form of an encoded

call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally assign ...

Maritime Mobile Service Identity A Maritime Mobile Service Identity (MMSI) is effectively a maritime object's international ''maritime telephone number'', a temporarily assigned UID, issued by that object's current flag state, (unlike an IMO, which is a global forever UID). ...

, starting with number "9" and the three country-specific

maritime identification digits Maritime identification digits are used by radio communication facilities to identify their home country or base area in Digital Selective Calling (DSC), Automatic Transmitter Identification System (ATIS), and Automatic Identification System (AIS) ...

. ATIS use on the Trans-European Inland Waterway network and connecting waterways is mandated by the Regional Arrangement Concerning the Radiotelephone Service on Inland Waterways (RAINWAT) agreements, which also prohibit the use of

Digital Selective Calling Digital selective calling or DSC is a standard for transmitting predefined digital messages via the medium-frequency (MF), high-frequency (HF) and very-high-frequency (VHF) maritime radio systems. It is a core part of the Global Maritime Distres ...

(DSC) where ATIS is required, except in some near-coastal areas, or in sea-like areas of The Netherlands. The database of ATIS vessel identities is maintained by the Belgian Institute for Postal Services and Telecommunications (fr) (nl). The ATIS signalling protocol is based on that used for

(DSC); with the ATIS transmissions having the format specifier field set to a value of 121. While DSC transmissions take place exclusively on Channel 70, the ATIS digital signal is transmitted on the same VHF channel as the voice transmission: it lasts for 285 milliseconds after the PTT button has been released, using

frequency modulation Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing. In analog fre ...

frequency-shift keying (FSK) between the frequencies of 1,300 Hz and 2,100 Hz at 1,200 baud. The core part of the message is transmitted using 10-bit codes; each code being formed of a 7-bit symbol followed by a 3-bit count of the number of zeros in that symbol.

References

Water transport in Europe Maritime communication {{europe-transport-stub