1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMM U N KATION STANDARDIZATION SECTOR OF ITU INTERWORKING WITH SATELLITE MOBILE SYSTEMS Q.1151 (03/93) INTERFACES FOR INTERWORKING BETWEEN THE INMARSAT AERONAUTICAL THE INTERNATIONAL PUBLIC SWITCHED TELEPHONE NETWORWISDN MOBILE-SATELLITE SYSTEM AND IT
2、U-T Recommendation Q.1151 (Previously “CCITT Recommendation”) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECNN*Q=LLSL 93 m 4862591 058423b 37T m FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent
3、 organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTS
4、C), which meets every four years, established the topics for study by the IT-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T Recommendation Q.1151 was revised by the ITU-T Study Group XI (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES
5、1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the
6、IFRB have been replaced by the Radiocommunication Sector. In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCIT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions
7、of this Recommendation will contain the proper terminology related to the new ITU structure. 2 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1994 All rights reserved. No par
8、t of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Service
9、sCONTENTS General . Service capabilities . 2.1 Channel capabilities 2.2 Bearer capabilities . 2.3 Teleservices Interworking scenarios . Connection interface requirements . 4.1 General 4.2 MSSC-network interface 4.3 AES-MSSC interface 4.4 Calling procedures air-to-ground 4.5 Calling procedures. groun
10、d-to-air . Routing requirements . 5.1 Ground originated calls . 5.2 Aircraft originated calls Appendix I . INMARSAT aeronautical mobile-satellite system description 1.1 Introduction 1.2 System evolution 1.3 Channel configuration 1.4 Link layer formats and protocols 1.5 Aircraft earth station managem
11、ent 1.6 Telephone services Page 1 1 1 2 2 2 4 4 4 4 4 5 5 5 5 5 5 7 9 10 11 11 Recommendation Q.1151 (03/93) 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECUN*QmLL5L 93 W 4862591 058Li238 142 Recommendation Q.1151 INTERFACES
12、 FOR INTERWORKING BETWEEN THE INTERNATIONAL PUBLIC SWITCHED TELEPHONE NETWORMSDN THE INMARSAT AERONAUTICAL MOBILE-SATELLITE SYSTEM AND (Melbourne 1988, modijed at Helsinki, 1993) 1 General 1.1 This Recommendation provides information on the services offered in the INMARSAT aeronautical mobile- satel
13、lite system and describes the requirements for connection to and interworking with the public networks. Special terminology for this Recommendation is defined in Recommendation Q. 1 100. Detailed interworking procedures are set out in Recommendation Q.1152. 1.2 As well as connection to public networ
14、ks, the aeronautical system is required to be able to interwork with existing specialized private networks. In implementing all interworking cases, regard should be paid to the open systems interconnection referenced model (X.200-Series Recommendations) and to ISDN services and signalling methods (I
15、-Series Recommendations), with a view to achieving uniformity in user procedures and formats and to achieving generally applicable facilities. 1.3 Within the constraint of the need to operate as economically as possible, the preferred interworking cases are with the ISDN and with those parts of the
16、international telephone network employing common channel signalling. If one of these is not available or accessible at the ISC to which an aeronautical ground earth station (GES) is connected then another signalling system from the Q-Series Recommendations should be used. 1.4 The use of the ISDN wil
17、l offer both improvement in quality and more flexibility in service. It will be possible to supply either voice or data over the same network with the ability to change from one to the other under control of the aircraft earth station (AES) terminal. 2 Service capabilities A general description of t
18、he INMARSAT aeronautical system is contained in Appendix I. 2.1 Channel capabilities 2.1.1 rates, including at least the following: The system provides circuit-mode single channel per carrier (SCPC) channels at a range of information bit 9600 bis; 4800 bis; 2400 bis Channels for other information bi
19、t rates, such as 64 O00 bids, may be defined in the future. 2.1.2 The system provides demand assigned forward (ground to air) TDM channels and return (air to ground) random access and (reservation) TDMA channels, at a range of bit rates. Although the following bit rates include housekeeping overhead
20、s, they are indicative of the information bit rates provided: 300 bit/s; 600 bit/s; 1200 bids; 2400 bids; 5250 bids. Channels for other bit rates may be defined in the future. Recommendation Q. 1151 (03/93) 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Informat
21、ion Handling ServicesITU-T RECMN*Q.LL53 93 4862593 0584239 089 AES 2.2 Bearer capabilities I I . GES MSSC 2.2.1 in Recommendation 1.21 1, may be supported: The following bearer services on SCPC channels, with the following information transfer attributes as defined a) speech (initially at 9.6 kbit/s
22、); transcoding to 64 kbit/s PCM should take place at the GES; b) circuit mode audio service (initially at 9.6 kbit/s), suitable for voice and other signals occupying the same bandwidth; transcoding to 64 kbit/s PCM should take place at the GES; c) virtual call bearer service at any of the bit rates
23、defined in 2.1.1, with rate adaptation in the GES to 64 kbit/s using, for example, flow control and flag stuffing; d) digital data, circuit mode interworking with the ISDN should take place as defined in Recommen- dation X.30 for data terminals designed to Recommendation X.21, and Recommendation X.3
24、2 for data terminals designed to Recommendation X.25. 2.2.2 The following bearer services on TDM, TDMA and RA channels may be supported: a) virtual call bearer service - interworking with the ISDN should take place as defined for interworking between PSPDNs and the ISDN. 2.3 Teleservices Teleservice
25、s, when supported, should be in accordance with Recommendation 1.212. It is to be observed that not all teleservices of ISDN may be supported with bearer services that can be provided on SCPC or TDM/TDMA channels operating at the available information bit rates. 3 Interworking scenarios Three interw
26、orking scenarios can be envisaged for the interface between the MSSC and the fixed networks. 3.1 services, and some voice services, handled via private networks. The first scenario is shown in Figure 1. The MSSC public network interface is to the PSTN only, with all data Private T1155860-9WdOl FIGUR
27、E l/Q.1151 Interworking scenario with PSTN interface 3.2 Figure 2 shows the situation where an ISDN exists and the MSSC has an interface to it. Interworking with the PSTN is acheived via the ISDN. Interworking with PDNs may be by direct interface with the PDN or via the ISDN, as in the case of the P
28、STN. 2 Recommendation Q.1151 (03/93) I COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN+Q-LLSL 93 = 486259L 0584240 8TO AES I GES MSSC I FIGURE 2/Q. 1 15 1 Interim interworking scenario with interfaces to ISDN and other fmed
29、networks AES GES MSSC. In this scenario interworking with the ISDN supports speech, 3.1 kHz audio and data services as indicated in 2.2.1. Other bearer services as indicated in 2.2.2 may require interworking with PDNs. 3.3 well as voice, although some voice and data services may still use private ne
30、tworks. The third scenario is shown in Figure 3. The MSSC interfaces to the ISDN, which provide data services as FIGURE 3/Q. 1 15 1 Interworking scenario with ISDN interface oniy Recommendation Q.1151 (03/93) 3 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Inform
31、ation Handling ServicesITU-T RECMN*Q.1151 93 m 48b2591 0584241 737 m 4 Connection interface requirements 4.1 General This subclause identifies the information that must be available at the interfaces between the AES and the MSSC and between the MSSC and the fixed network, principally for the connect
32、ion of services identified in 3. 4.2 MSSC-network interface For ISDN connections ISUP should be used for message transfer. For non-ISDN or where ISUP is not available, TUP would be preferred. If information transport between MSSCs over the fixed network is required, it is suggested that the procedur
33、es of the SCCP is used. Detailed interworking procedures are defined in Recommendation Q. 1152. 4.3 AES-MSSC interface Prior to and during call initiation the signalling channel functions may be provided by one or more common control channels. A signalling capability should always be available durin
34、g conversation in case it is needed for call clearing, call control, or for call management purposes. During a call the signalling channel may be multiplexed with the traffic channel at a lower bit rate so as to conserve radio channel capacity. The multiplexed signalling channel or TDM/TDMA/RA chann
35、els may be used for bearer services such as connectionless data services, or connection oriented data services not requiring the establishment of a traffic channel. The traffic channel should be used for bearer services such as: - speech; - circuit mode data services; - packet mode data services; -
36、voice band data services. 4.4 Calling procedures air-to-ground 4.4.1 Passenger telephony operation a) The equipment for passenger telephony may consist of the following: - theAES; - cabin telephone equipment consisting of a fixed piece of equipment and a handset, which may be “cordless”. The fixed c
37、abin telephone equipment should be provided with a credit card reader. When a passenger wants to make a call, the typical sequence of events would be as follows: i) key-in seat number; ii) when this is accepted, insert credit card; and iii) when this is accepted, remove handset and return to seat. A
38、t the cabin telephone location, if a credit card which corresponds to the recognized card format is inserted into the equipment, the handset shall be released after validation of the check bits and expiry date. In the event that either of these checks fail, the card shall be returned and the handset
39、 not released. Upon obtaining the handset the customer returns to his seat and can commence making one or more telephone calls. Where telephones and associated credit card readers are located at the passengers seats, a somewhat different procedure may apply. However, the procedure will still involve
40、 reading the credit card, validating the check bits and checking expiry date, before making calls. b) c) d) 4 Recommendation Q.1151 (03/93) I COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECHN*Q.LLSL 93 4862591 0584242 673 W 4.
41、4.2 Crew telephony operation For this case, credit card validation procedures are not required. Crew will have access to special telephone services and networks, according to requirements and procedures developed by the industry. The capabilities will include at least the following: a) access to the
42、 full public telephone network as for passengers, but without the need for a credit card (billing would be direct to the aircraft operator); access to specialized voice services via private networks, with or without address digits; ability to preempt an existing (passenger) call if necessary to make
43、 AES voice circuit equipment, a satellite channel or GES voice circuit equipment available; b) c) d) ability to seize the next available AES voice circuit equipment, but without clearing any calls in progress. 4.5 Calling procedures, ground-to-air 4.5.1 address digits. Operator connected access may
44、also be available. Selected fixed network users should be able to access aircraft automatically by using the aircraft ID in the 4.5.2 The numbering plan to enable a PSTN subscriber to call the AES is defined in Recommendation E.215. 5 Routing requirements 5.1 Ground originated calls The country code
45、 87s should be analysed at all transit centres where the call may either be routed on a circuit containing a satellite link or on a circuit not containing a satellite link. The latter circuit should always be chosen (see Recommendation Q. 14). 5.2 Aircraft originated calls If the signalling system p
46、rovided between the MSSC and the terrestrial network contains signals which may be used to indicate that one satellite link is included, such signals should be used. If the signalling system does not contain such signals, the outgoing ISC should avoid forwarding the call on an outgoing circuit which
47、 includes a satellite link. If, however, the signalling system employed between the outgoing ISC and the next ISC in the connection contains such signals, the outgoing ISC should insert the required information. The outgoing ISC could base its procedure upon incoming route identification. Appendix I
48、 INMARSAT aeronautical mobile-satellite system description (This appendix does not form an integral part of this Recommendation) 1.1 Introduction The aeronautical satellite system is a mobile communications system intended for use by aircraft in flight. It can provide voice communication services an
49、d a range of data communications services. 5 Recommendation Q.1151 (03/93) 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*Q.1151 93 4862591 0584243 50T 1.1.1 also Figure 1.1): The major elements of the aeronautical satellite system as described in this appendix are as follows (see space segment, in particular the satellite communication transponders and associated frequency bands assigned for use by the aeronautical satellite system; aircraft earth stations (AES) which are in accordance with the relevant
