Commandant (G-TTM) U.S. Coast Guard 5 May 1995 Washington DC 20593 MARITIME DISTRESS & SAFETY TELECOMMUNICATION DATA ELEMENTS The following data elements are used in the transmission of maritime distress and safety information between the Coast Guard and ships at sea. These elements are defined by international conventions or standards organizations, such as the International Telecommunications Union (ITU) Radio Regulations or ITU Sector for Radiocommunications. Each data element listed is necessary to either contact a ship at sea, or identify the sender of a distress alert. Since data described in these elements may provide the only means for Coast Guard Operations Centers to identify and contact vessels in distress, a means to accurately identify and relate these elements to several kinds of search and rescue and telecommunications-related data bases is essential to safety of life. The data elements specified are currently in use for maritime distress, safety and routine telecommunication purposes, and are defined by international organizations outside the Coast Guard. Name of the new system or application: GLOBAL MARITIME DISTRESS & SAFETY SYSTEM DATA ELEMENT NAMES AND DEFINITIONS CALL SIGN Definition: A unique identifier of a radio station. Named by ITU. (see Article 25 of the ITU Radio Regulations) Used for: manual identification of Morse and radiotelephone ship and coast stations, 406 MHZ EPIRBs, other radio transmissions. Data element data type: Character string Data element maximum length: 7 characters Data element domain: alphanumeric Alias name: Radio Call Sign MARITIME MOBILE SERVICE IDENTITY Definition: "Maritime mobile service identities are formed of a series of nine digits which are transmitted over the radio path in order to uniquely identify ship stations, ship earth stations, coast stations, coast earth stations and group calls." Named by ITU. (from AP43 1.1 of the ITU Radio Regulations) Used for: DSC identifier, 406 MHZ EPIRB identifier, SITOR (narrow-band direct printing) identifier. Data element data type: character string Data element maximum length: 9 digits Data element domain: numeric Alias NAME: MMSI (abbreviation approved by ITU), or Digital Selective Calling (DSC) number. Note: This data element will be essential in establishing contact with vessels after 1 Feb 1999. Note: The first three digits of the MMSI are Maritime Identification Digits defined by Appendix 43 of the ITU Radio Regulations, identifying the country to which the vessel belongs. "366" is one of the MID assigned to the United States. This number is also used by several foreign countries for 406 MHZ EPIRBs. SELECTIVE CALL NUMBER Definition: A unique numeric identifier of a ship or coast station in the maritime mobile service for simplex teletype over radio (SITOR). Named by ITU. (see Article 25 of the ITU Radio Regulations) Used for: SITOR identifier (being replaced by MMSI) Data element data type: character string Data element maximum length: 5 (ship stations) or 4 (coast stations) digits Data element domain: numeric only Alias name: SITOR number MOBILE EARTH STATION IDENTIFICATION NUMBER (MESIN) Definition: A unique numeric identifier of an INMARSAT-C, INMARSAT-M, INMARSAT-B and all new INMARSAT ship earth station. Named by the INMARSAT Organization. Used for: Calls to INMARSAT (except INMARSAT-A) satellite terminals on ships. INMARSAT-C (as of summer 92, the only non-A operational system) is restricted to data or telex only. Data element data type: character string Data element maximum length: 9 digits Data element domain: numeric only Its format is "TMIDXXXZZ" where T = type of terminal ("4" for INMARSAT-C) MID is Maritime Identification Digits (see MMSI) XXX is digits 4-6 of the MMSI, provided the MMSI ends in three zeros. ZZ is the ship's extension number (the primary extension is always "10) Note: The nine digit Inmarsat number is related to the MMSI as follows: TMIDNNN10 ==> MIDNNN000 where T =: 0 - Inmarsat A group call 1 - Inmarsat A (7 digits only) 2 - (reserved) 3 - Inmarsat B 4 - Inmarsat C (49 - land mobile Inmarsat C) 5 - Aeronautical 6 - Inmarsat M 7 - (reserved) 8 - Inmarsat A special use (81 = fax, 82 = X.25) 9 - (future use) For example, a US vessel having an Inmarsat C identity of 436612310 should have a DSC number (MMSI identity) of 366123000. You can always tell the type of terminal used by the first digit; for example, if you need to contact a vessel having an Inmarsat identity beginning with "4", you can only call by telex. Alias name: INMARSAT MOBILE NUMBER or INMARSAT-C number SHIP EARTH STATION IDENTITY NUMBER Definition: A unique numeric identifier of an INMARSAT-A ship earth station. Named by the INMARSAT Organization. Used for: Calls to INMARSAT-A satellite terminals on ships. Same number is used for both telephone and telex. Data element data type: character string Data element maximum length: 7 digits Data element domain: numeric only Alias name: SES ID or Primary ID (Named by the INMARSAT Organization) SHIP STATION IDENTITY Definition: A unique numeric identifier of an INMARSAT-E EPIRB. Used for: Identification of INMARSAT-E EPIRBs Data element data type: Character string Data element maximum length: 9 digits Data element domain: Numeric only Alias name: INMARSAT-E EPIRB serial number, or L-band EPIRB serial number. Note: This number is maintained in a registration database by Inmarsat. It has no relationship with the MMSI or other identity. 406 MHZ EPIRB UNIQUE IDENTIFIER NUMBER Definition: A unique alphanumeric identifier of a 406 MHZ satellite EPIRB. Used for: Identification of 406 MHZ EPIRBs Data element data type: character string Data element maximum length: 15 characters Data element domain: hex number Alias name: Unique Identifier Number, or 406 MHZ EPIRB HEX number. Note: This number is maintained in a registration database by NOAA/NESDIS (U.S.) and by similar organizations in each country using this method of identity. CANDIDATE PRIME WORDS. STATION. STATION refers to ship or coast radio station, EPIRB, or other device transmitting a radio signal.