SECTION 1
                                          
                                          
                                          
                    INTERWORKING WITH STANDARD A INMARSAT SYSTEM





Recommendation Q.1100



                      STRUCTURE OF THE RECOMMENDATIONS ON THE
                         INMARSAT MOBILE SATELLITE SYSTEMS



1     General


      This Recommendation gives an overview of those in the Q.1100-Series for interworking between 
the international public switched telephone  network/ISDN  and  the  INMARSAT  mobile
satellite systems.  It also contains definitions of the  terminology  used  in  these
Recommendations.



2     Terminology



2.1   aeronautical (ground) earth station (GES)

      An earth station in the fixed satellite service or, in some cases, in the aeronautical mobile- 
satellite service, located at a specified fixed point on land  to  provide  a  feeder
link for the aeronautical mobile-satellite service (see Radio Regulations Article 1).

2.2   aircraft earth station (AES)

      A mobile earth station in the aeronautical mobile-satellite service located on board an 
aircraft (see Radio Regulations Article 1).

2.3   mobile satellite switching centre (MSSC)

      Indicates the signalling interworking point between the fixed networks and the mobile satellite 
system which works to a single ocean area. The MSSC may be  located  at  the  antenna
site of the aeronautical ground earth station or coast earth station, in which case it 
may operate as an independent international switching centre (ISC) connected to one or 
more ISCs, on national switching centres. It may also be located  remotely  from  the
antenna site, as a supplement to, or a part of an ISC. The term MSSC may also indicate aw 
maritimew satellite switching centre, with an identical functional definition to  the
above.
2.4   international switching centre (ISC)

      The exchange (at the end of an international circuit) which switches calls destined to or 
originating from another country.

2.5   ship earth station (SES)

       A station in the maritime mobile satellite service intended to be used while in motion or 
during halts at unspecified points and which is located on board a  ship  (see  Radio



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Regulations Article 1).

2.6   integrated services digital network (ISDN)

      An integrated digital network in which the same digital switches and digital paths are used to 
establish connections for different services, such as telephony, data, and so on (see 
CCITT I-Series Recommendations).

2.7   telephone user part (TUP)

      This defines the necessary telephone signalling functions for use of Signalling System No. 7 
(SS No. 7) for international call control signalling. It is specified with the aim of 
providing the  same  feature  for  telephone  signalling  as  other  CCITT  telephone
signalling systems (see CCITT Recommendation Q.721).

2.8   ISDN user part (ISUP)

      This encompasses the signalling functions in SS No. 7 required to provide switched services and 
user facilities for voice and non-voice applications in an ISDN  (see  Recommendation
Q.761).

2.9   signalling connection control part (SCCP)

      This provides in SS No. 7 additional functions to the message transfer part to cater for both 
connectionless as well as connection oriented network services, to  transfer  circuit
related, non- circuit related signalling information, and other types of  information
between exchanges and specialised centres in telecommunication  networks  (see  CCITT
Recommendation Q.711).

2.10  coast earth station (CES)

      An earth station operating in the fixed satellite service frequency bands or, in some cases, in 
the maritime mobile-satellite service frequency bands located at  a  specified  fixed
point on land to provide a feeder link for the maritime mobile-satellite service (see 
Radio Regulations, Article 1).


3     Overview of Recommendations


3.1  Recommendation Q.1101

      Sets out the general requirements for interworking between the first generation (Standard A) 
INMARSAT system and the international public telephone network. A  brief  description
of the INMARSAT Standard A system is also included.

3.2  Recommendation Q.1102

      Specifies the interworking between the INMARSAT Standard A system and Signalling System R2.

3.3  Recommendation Q.1103

      Specifies the interworking between the INMARSAT Standard A system and Signalling System No. 5.

3.4  Recommendation Q.1111

      Provides information on services offered in the INMARSAT Standard B system, and describes the 
requirements for connection and internetworking with the  public  networks.  A  brief
description of the Standard-B system is appended.







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3.5  Recommendation Q.1112

      Presents the procedures for interworking between the INMARSAT  Standard B system and the 
signalling systems of the international public network.

3.6  Recommendation Q.1151

      Provides information on the services offered in the INMARSAT aeronautical system and describes 
the requirements for connection and interworking with the public  networks.  A  brief
description of the aeronautical system is appended.

3.7  Recommendation Q.1152

      Presents the procedures for interworking between the INMARSAT aeronautical system and the 
signalling systems of the international public network.





















































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