ITU-T R 91-1988 GENERAL MAINTENANCE ASPECTS FOR THE MARITIME SATELLITE TELEX SERVICE《海上卫星用户电报业务的一般维护要求》.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 2 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%2!0(94%,%2!0(G0G042!.3-)33)/.%.%2!,G0G0-!).4%.!.#%G0G0!30%#43G0G0(b) that it is advantageous that the maintenance procedures used in the maritime satellite telex service aresimilar to those used in the in

2、ternational telex service;(c) that, from a maintenance and transmission point of view, the maritime satellite system may be regarded asanalogous to a national network and the ship earth stations as somewhat analogous to subscriber terminals within thatnetwork;(d) that the ship earth stations are con

3、nected to a coast earth station on a demand assignment basis and,therefore, the coast earth station may not have the direct responsibility for the maintenance of a particular ship earthstation all the time;(e) that the required staff and facilities may not be available at a ship earth station for ma

4、intenance purposes,unanimously recommendsthat the maintenance of telex circuits in the maritime satellite service should be based on the followingprinciples:1 The principles and methods for the maintenance of telegraph circuits contained in the Series R,Recommendations should be followed.2 The coast

5、 earth stations or the associated telex switching centre should act as a control station for the maritimesatellite telex circuits as defined in Recommendation R.71.3 Similar principles as those defined in Recommendation M.1110 for the cooperation between maintenanceelements of the INMARSAT system an

6、d the international telephone network should also apply to the INMARSATsystem and the international telex network. The overall maintenance organization of the INMARSAT system isdescribed in Recommendation M.1110.4 The coast earth stations or the associated telex switching centres should act as STCs

7、switching and testingcentres) as defined in Recommendation R.90 for access by ship earth stations for the purpose of fault reporting andtesting.4.1 The ship earth stations would access the STC at a coast earth station or its associated telex switching centre byusing the telex access code 33 (techni

8、cal assistance) as defined in Recommendation F.121.4.2 Automatic test equipment at the STC is to be accessed by the telex access code 91 (automatic test line) asdefined in Recommendation F.121.Note In the first generation INMARSAT system the test access will be to a termination which returns the“QUI

9、CK BROWN FOX . . . ” sequence.5 In order to facilitate end-to-end testing of telex connections without involving a ship earth station, the maritimetest terminal required by INMARSAT to be associated with each coast earth station should be used.The description of the maritime test terminal and its capabilities is given in Recommendation M.1100.