1、QUESTION ITU-R 109-1/4*, *Global Maritime Distress and Safety System requirements for mobile-satellite systems operating in the bands 1 530-1 544 MHz and 1 626.5-1 645.5 MHz (1992-2007) The ITU Radiocommunication Assembly, considering a) that the requirements for the Global Maritime Distress and Saf
2、ety System (GMDSS) entered into force on 1 February 1992 in accordance with the 1988 Amendments to the 1974 International Convention for the Safety of Life at Sea (SOLAS) concerning radiocommunications for the GMDSS; b) that multiple mobile-satellite systems designed for operation in the 1 530-1 544
3、 MHz and 1 626.5-1 645.5 MHz bands are currently being developed and introduced; c) that the 1 530-1 544 MHz and 1 626.5-1 645.5 MHz bands, used for GMDSS distress and safety communications (see Table 15-2 of Appendix 15 to the Radio Regulations), are also available for other services; d) that curre
4、ntly the International Maritime Organization (IMO) has recognized only one provider of mobile-satellite communications (Inmarsat) for the GMDSS in these bands; e) that if multiple mobile-satellite systems operate in these bands, not all may elect to participate in the GMDSS; f) that, as a major elem
5、ent of the GMDSS, the satellite system provides for priority processing of distress alerts from ship earth stations to the coast earth stations; g) that coast earth stations provide for expeditious handling and delivery of distress messages to their associated rescue coordination centres; h) that, i
6、n these frequency bands, distress and safety receives the highest order of priority of communications in the maritime mobile-satellite service; j) that, in these frequency bands, any emission causing harmful interference to maritime mobile-satellite distress and safety communications is prohibited;
7、k) that satellite systems participating in the GMDSS may provide a number of telecommunication services not associated with the GMDSS; l) that use of these bands for distress and safety purposes in the maritime mobile-satellite service is an important part of the GMDSS; m) that implementation of the
8、se telecommunication services under the GMDSS has been ongoing for some time, _ * This Question should be brought to the attention of the International Maritime Organization (IMO), the International Civil Aviation Organization (ICAO) and the Telecommunication Standardization Bureau. *Former Question
9、 ITU-R 109-1/8. - 2 - decides that the following Question should be studied 1 What percentages of the total number of ship earth stations may be expected to be simultaneously conducting distress and safety communications in the GMDSS in the various oceanic areas and what traffic studies should be un
10、dertaken to assure the required grade of safety service? 2 What should the technical and operational characteristics be for mobile-satellite systems operating in the 1 530-1 544 MHz and 1 626.5-1 645.5 MHz bands in relation to distress and safety communications in the GMDSS? 3 What techniques includ
11、ing real-time pre-emption or the use of dedicated channels can be used to provide the necessary protection and priority access for maritime mobile service distress and safety communications in these bands? 4 What inter-system and intra-system protection criteria should be established for mobile satellite systems operating in these bands? further decides 1 that the results of the above studies should be included in (a) Recommendation(s); 2 that the above studies should be completed before 2007. Category: S1
