7.3 Registered information providers shall take into account the need for contingency planning. 7.4 Scheduled transmissions are made at specified as allocated by the IMO International Satellite EGC Coordinating Panel. These schedules are published in national nautical publications and the IMO Master Plan of Shore-Based facilities for the GMDSS, as amended. 7.5 MSI providers shall adhere to their published scheduled broadcast times to facilitate reception of messages. 8 Message formatting and C codes 8.1 EGC messages include instructions to the LES for processing MSI in the form of a special address header that consists of five (or six) C codes as described below. In order for a message to be correctly processed, it shall always consist of data conforming to C codes "1" to "5". Additionally, C code "0" shall be used when required by the service provider. C0 Region code – 1 digit (when required) 0 – Atlantic Ocean Region – West 1 – Atlantic Ocean Region – East 2 – Pacific Ocean Region 3 – Indian Ocean Region 9 – all regions served by the addressed LES (Note: availability of C0 = 9 should be checked with the LES operator or service provider) C1 priority code – 1 code C2 service code – 2 digit code C3 address code – 2, 4, 10 or 12 alphanumeric code C4 repetition code – 2 digit code C5 presentation code – 1 or 2 digit code C Codes C0 Ocean Region code (when required) C1 Priority code C2 Service code C3 Address code C4 Repetition code (see 4, part E) C5 Presentation Code 1 digit code 1 digit code 2 digit code 2, 4, 10 or 12 alphanumeric code 2 code 1 or 2 digit code 0 – 1 – 2 - POR 3 – IOR 1 – Safety 2 – Urgency 3 00 – All ships (general call) 2 digit – 00 (All ships) 04 – Navigational, meteorological or piracy warning or meteorological forecast to a rectangular area 12 alphanumeric rectangular area address D1D2N(S)D3D4D5E(W)D6D7D8D9D10 13 – Navigational, meteorological, coastal or piracy warning or meteorological 4 alphanumeric coastal warning area address X1X2B1B2 E W
Annex 3 The Iridium Global Mobile-Satellite System 1 Introduction 1.1 Iridium Satellite LLC owns and operates a Global Mobile Personal Communications by Satellite (GMPCS) system providing fully global digital communications. The major components of the Iridium mobile-satellite system are: 1.1.1 The space segment, consisting of 66 operational satellites and additional in-orbit spare satellites; 1.1.2 The ground segment, consisting of satellite teleports (“teleports”) for the transfer of voice and data communications between the gateways and the satellite constellation, and gateways which provide connection to terrestrial voice and data networks; and 1.1.3 Mobile earth stations, which consist of a satellite modem, which is incorporated into a commercial product, and an externally installed antenna. 1.2 The satellite constellation provides the communication between the user terminals and the teleport(s), which are interconnected to the gateways. The gateways serve as the switching center, routing all communications into and from terrestrial networks, such as the PSTN. The gateway also locates, identifies and tracks subscribers for mobility management, and records user activity for billing purposes. 1.3 These components are illustrated in Figure 7 below:
C2 = 24 – Navigational warning to a circular area C2 = 31 – NAVAREA warning to a NAVAREA Meteorological services C1 = 1 (Safety) – always for forecasts and warnings C1 = 2 (Urgency) – always for urgent tropical cyclone warnings only C2 = 04 – Meteorological warning or forecast to a rectangular area C2 = 13 – Meteorological warning or forecast to a coastal warning area C2 = 24 – Meteorological warning or forecast to a circular area C2 = 31 – METAREA warning or meteorological forecast to a METAREA SAR services: Shore-to-ship distress alert C1 = 3 (Distress) – always C2 = 14 – distress alert to a circular area SAR coordination traffic C1 = 1 (Safety) – determined by the of emergency C1 = 2 (Urgency) – determined by the phase of emergency C1 = 3 (Distress) – determined by the phase of emergency C2 = 34 – SAR coordination to a rectangular area C2 = 44 – SAR coordination to a circular area Shore-to-ship urgency and safety traffic C1 = 1 (Safety) C1 = 2 (Urgency) C2 = 31 – Urgency and safety traffic General (all ships call within the Inmarsat ocean region) C1 = 2 (Urgency) C1 = 3 (Distress) C2 = 00 Piracy countermeasures broadcast messages C1 = 1 (Safety) C1 = 2 (Urgency) – for piracy attack warnings C2 = 04 – Piracy warning to a rectangular area C2 = 13 – Piracy warning to a coastal warning area C2 = 24 – Piracy warning to a circular area C2 = 31 – Piracy warning to a NAVAREA
7.1 C1 – Message priority C1 = 2 (urgency) 7.2 C2 – Service code C2 = 13 Coastal warning C2 = 31 NAVAREA warning 7.3 C3 – Address code C3 = two digits X1X2 When C2 = 31 then: X1X2 are the two digits of the NAVAREA number (with a leading zero where necessary in the range 01 to 21) C3 = four alphanumeric characters X1X2B1B2 When C2 = 13 for coastal warnings then: X1X2 are the two digits of the NAVAREA number (with a leading zero necessary in the range 01 to 21) B1 is the coastal warning area A to Z B2 is the subject indicator and must always be A or L, where: A = Navigational warnings L = navigational warnings 7.4 C4 – Repetition code C4 = 16 Broadcast every 12hours with no echo until cancelled 7.5 C5 – Presentation code C5 = 00 The code 00 for International Alphabet Number 5 is normally used 8 Date/time should always be quoted in the form: DDHHMM UTC MoMoMo YY as in the example: 251256 UTC JUN 17 Note: UTC (Coordinated Universal Time) is the same time-zone as GMT (Z). 9 Geographical positions should be quoted in the standard format: D1D2M1M2LaD3D4D5M3M4Lo where: D1D2 = degrees latitude (with leading zero if required) M1M2 = minutes latitude La = hemisphere (N or S)