ITU-R QUESTION 93-25-1993 Automation of MF HF and VHF maritime mobile communications《中频 超短波和甚高频海上移动通信自动化》.pdf

1、QUESTION ITU-R 93-2/5*,*Automation of MF, HF and VHF maritime mobile communications(1988-1992-1993)The ITU Radiocommunication Assembly,consideringa) that there is a need for automatic facilities for handling radiotelephone calls in the maritimemobile service, particularly from ship-to-shore;b) that

2、automatic operation would also be desirable in the shore-to-ship direction;c) that there is a need to ensure compatibility of automatic ship equipment with the differentcoast stations which the ship station is likely to contact;d) that an automatic VHF/UHF radiotelephone system for the maritime mobi

3、le service hasbeen defined in Recommendation ITU-R M.586 but is not foreseen to come into service in theimmediate future;e) that Articles 52 and 57 of the Radio Regulations do not permit coast stations to emitidle-channel signals on radiotelephone working channels;f) that the digital selective-calli

4、ng (DSC) system described in RecommendationsITU-R M.493 and ITU-R M.541 could be used for signalling over the radio path for such anautomatic system using common DSC channels;g) that the existing MF, HF and VHF working channels should be used in such an automaticsystem, if possible without impairing

5、 their use for manual operations from the same ship or coaststation;h) that such a system would not hamper the subsequent development of a fully automaticdigital system;j) that a VHF radiotelephone system with automatic facilities based on RecommendationITU-R M.689 has been established;k) that autom

6、ation of other maritime mobile communications services would also be desirable,decides that the following Questions should be studied1 What are the preferred technical and operating characteristics for ship and coast stationequipments providing automatic connection of calls in the ship-to-shore dire

7、ction in the maritimemobile service MF, HF and VHF bands to the public switched networks?2 What conditions must be met for extending this automatic service to calls in theshore-to-ship direction?3 What conditions should be observed to ensure that the system can use the existing MF, HFand VHF working

8、 channels without in any way impairing current manual operations?4 What are the conditions for ensuring the international operation of the system?NOTE 1 Aspects of 1, 2 and 4 are also included in ITU-T Question 6/2._* This Question should be brought to the attention of the International Maritime Organization (IMO).* Former Question ITU-R 93-2/8.