3.3 Priority access
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Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.1001(25) – Criteria for the Provision of Mobile Satellite Communication Systems in the Global Maritime Distress and Safety System (GMDSS) – (Adopted on 29 November 2007) - Annex – Criteria for the Provision of Mobile Satellite Communication Systems in the Global Maritime Distress and Safety System (GMDSS) - 3 Criteria and Requirements for the Recognized Mobile Satellite Communication System - 3.3 Priority access

3.3 Priority access

  3.3.1 Satellite systems in the GMDSS should be capable of processing maritime distress, urgency, safety and routine communications in accordance with the message priority as defined by the ITU Radio Regulations. The order of processing these communications should be:

  • .1 distress;

  • .2 urgency;

  • .3 safety; and

  • .4 routine (general communications).

  3.3.2 In implementing these four levels of priority:

  • .1 Distress alerts and distress calls (level 1) should be given priority treatment by providing immediate access to satellite channels. For store and forward systems, distress alerts and calls should be placed ahead of all other traffic.

  • .2 Satellite systems used for providing other mobile satellite communications in addition to maritime communications should be capable of automatically recognizing requests for maritime communications from:

    • maritime mobile terminals; and
    • recognized entities of critical importance for safety at sea, such as MRCCs, hydrographic and meteorological offices, medical centres, etc., registered with the earth station.

    The system should process such maritime communications in the ship-to-shore and shore-to-ship directions for levels 1 to 3 with priority over other communications.

  • .3 In processing maritime distress, urgency, safety and routine communications, the satellite system and the earth station should be capable of:

    • .1 automatically recognizing the message or access priority for ship-to-shore communications;

    • .2 automatically recognizing the message or access priority for shore-to-ship communications, if any are provided, from, as a minimum, recognized entities of importance for safety at sea, registered by the earth station;

    • .3 preserving and transferring the priority;

    • .4 giving distress alerts and distress calls immediate access, if necessary by pre-empting ongoing communications of routine priority;

    • .5 automatically recognizing maritime distress communications and automatically routeing maritime distress alerts and distress calls directly to an associated MRCC, or responsible RCC if this capability exists; and

    • .6 processing maritime urgency and safety communications in the ship-to-shore and shore-to-ship directions with the required priority, for example by allocating the first vacant channel, if no channel is immediately available.

  • .4 Selection and use of message or access priority for urgency and safety transmissions by maritime mobile terminals should preferably be automatic and should be restricted to calls to special, recognized entities such as medical centres, maritime assistance, hydrographic and meteorological offices, etc., registered with the earth station. The earth station should automatically route such calls directly to the relevant entity.

Parent topic: 3 Criteria and Requirements for the Recognized Mobile Satellite Communication System
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