1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 1 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU).4%27/2+).G0G07)4(G0G03!4%,)4%-/“),%G0G03934%-3).4%27/2+).G0G0“%47%.3).!,).G0G03934%-G0G0.O G0 G0G0!.$).-!23!4G0G034!.$!2$G0G0!G0G03934%-)45G134G0G0RecommendationG0G01 (Extract from the “LUEG0“OOK)NOTES1 ITU
2、-T Recommendation Q.1103 was published in Fascicle VI.14 of the Blue Book. This file is an extract fromthe Blue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, thecontents of the file are identical to the Blue Book version and copyright con
3、ditions remain unchanged (see below).2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both atelecommunication administration and a recognized operating agency. ITU 1988, 1993All rights reserved. No part of this publication may be reproduced or utilized in
4、 any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the ITU.Fascicle VI.14 - Rec. Q.1103 1Recommendation Q.1103Fascicle VI.14 - Rec. Q.1103INTERWORKING BETWEEN SIGNALLING SYSTEM No. 5AND INMARSAT STANDARD A SYSTEM1 Introduction
5、It is necessary to specify the interworking of Signalling System No. 5 and the signalling system used in theINMARSAT Standard A system. This is because:a) it may be desirable that a Maritime Satellite Switching Centre (MSSC)1)be connected to an internationalswitching centre (ISC) by employing System
6、 No. 5 on circuits between the MSSC and the ISC;b) the signalling systems used in the Maritime Mobile-Satellite Service will be different from System No. 5.Therefore it would be necessary to establish rules by which signalling events in one system may berelated to corresponding events in the other s
7、ystem.It is desirable that the interworking be such that the full capability of both System No. 5 and the maritimesatellite signalling system can be utilized.This Recommendation considers only automatic interworking between the MSSC and an ISC utilizingSystem No. 5.For description of the INMARSAT St
8、andard A signalling system, see Annex A to Recommendation Q.1101.2 Calls from Signalling System No. 5 to the maritime system (see figure 1 /Q.1103)2.1 The ISC sends the seizing signal followed by either of the following sequences of address signals:2.1.1 Signal KP1 followed by the discriminating (or
9、 language) digit and the number of the wanted ship earthstation when the country code 87S is not required for routing in the MSSC.2.1.2 Signal KP2 followed by 87S, discriminating (or language) digit and the number of the wanted ship earthstation when the country code is required for routing in the M
10、SSC.2.2 The MSSC register should ignore further digits when either:a) the ST signal has been received by the MSSC, orb) the busy-flash signal has been sent by the MSSC.2.3 The answer signal should be sent in the backward direction as soon as the answer signal over the satellite linkhas been detected
11、._1)For definition, see Recommendation Q.1101.2 Fascicle VI.14 - Rec. Q.11032.4 The busy-flash signal should be sent if the call cannot be completed for any of the following reasons:a) congestion at the MSSC or in the maritime satellite system;b) the satellite channel has not been assigned within 20
12、 seconds of the receipt of the ST signal;c) the NCS/MSSC is out of service.2.5 If the called ship earth station is busy, then the MSSC may either return the busy tone or the busy-flashsignal.2.6 The special information tone should be sent if the call cannot be completed for any of the following reas
13、ons:a) the ship earth station does not respond to the call;b) the called ship earth station is excluded from participating in the service;c) the received number does not belong to any ship earth station;d) the received number is an unauthorized group call;e) the called ship earth station is faulty;f
14、) continuity of the satellite link is not established.2.7 When a clear-back signal is detected on the satellite link, this signal shall result in sending of the clear-backsignal on the terrestrial connection. The satellite link should be released so that the provisions ofRecommendation Q.118 do not
15、apply for this part of the connection.2.8 When the MSSC detects the clear-forward from the terrestrial network, the terrestrial and satellite links willclear down according to their respective specification. If, however, switching at the MSSC is achieved by directfrequency selection, then it will be
16、 necessary to delay the release guard on the terrestrial link until the satellite link isidle.2.9 For the SDL description of incoming System No. 5, see Recommendation Q.612 1.2.10 The SDL description of interworking between incoming System No. 5 and outgoing INMARSAT signallingsystem is given in ann
17、ex A.2.11 For the SDL description of outgoing INMARSAT signalling system, see Annex C toRecommendation Q.1101.3 Calls from the maritime satellite system to Signalling System No. 5 (see figure 2/Q.1103)3.1 The terrestrial circuit should not be seized before a satellite channel has been allocated, the
18、 continuity of thechannel has been verified, and all digits have been received.3.2 The KP signal should be used subject to the following conditions:a) KP1 if the call is terminated in the MSSC country (in this case the country code is suppressed) or inanother country having direct connection to the
19、MSSC;b) KP2 if the call is transit connected to another country.3.3 The discriminating digit should be inserted according to 2.3.4 The ST signal should be sent according to 3.3.5 The congestion tone should be sent to the ship earth station when the busy-flash signal is received.Fascicle VI.14 - Rec.
20、 Q.1103 33.6 Time-out supervision of the answer signal at the MSSC should comply with the provisions ofRecommendation Q.118, 4.3.1.3.7 If the MSSC receives a clear-back signal from the terrestrial network, the time-out ofRecommendation Q.118, 4.3.2 shall be started. The satellite and terrestrial lin
21、ks will be cleared either by the shipearth station or by expiry of the 1-2 minutes time-out.3.8 When the MSSC detects a release condition on the satellite link, the terrestrial connection should be clearedforward as soon as possible.3.9 For the SDL description of outgoing System No. 5, see Recommend
22、ation Q.622 4.3.10 The SDL description of interworking between incoming INMARSAT Standard A signalling system andoutgoing System No. 5 is given in Annex B.3.11 For the SDL description of incoming INMARSAT signalling system, see Annex B toRecommendation Q.1101.ANNEX A(to Recommendation Q.1103)Logic p
23、rocedures for interworking of Signalling System No. 5to the INMARSAT Standard A signalling system4 Fascicle VI.14 - Rec. Q.1103 Fascicle VI.14 - Rec. Q.1103 5ANNEX B(to Recommendation Q.1103)Logic procedures for interworking of the INMARSAT Standard Asignalling system to the Signalling System No. 5S
24、upervisory timers for interworking of the INMARSAT Standard A signalling system to Signalling System No. 5t1= 2-4 minutes Recommendation Q.118, 4.3.1t2= 1-2 minutes Recommendation Q.118, 4.3.2t3= 20 secondsFigure B-2/Q.1103Notes to interworking of the INMARSAT Standard Asignalling system to Signalli
25、ng System No. 56 Fascicle VI.14 - Rec. Q.1103 Fascicle VI.14 - Rec. Q.1103 7 8 Fascicle VI.14 - Rec. Q.1103References1 CCITT Recommendation Logic procedures for incoming Signalling System No. 5, Vol. VI. Rec. Q.612.2 CCITT Recommendation Analysis of digital information for routing, Vol. VI, Rec. Q.155, 3.4.5.3 CCITT Recommendation End-of-pulsing conditions - Register arrangements concerning ST (end-of-pulsing)signal, Vol. VI, Rec. Q.152, 3.2.1, b), (2).4 CCITT Recommendation Logic procedure for outgoing Signalling System No. 5, Vol. VI, Rec. Q.622.
