ARINC 741P2-11

Overview

The Aviation Satellite Communication System (satcom) is aworldwide mobile communications system providing voice and datacommunications services between aircraft subnetworks and groundsubnetworks.

The satellite network, in conjunction with avionics implementedin accordance with this document, provides air-groundpacket-switched data services and voice communications usingconventions and capabilities which are standardized worldwide. Theuse of circuit-switched channels for data and facsimile services isalso possible.

The goal of satcom is to provide the civil aviation communitywith worldwide, highquality safety and non-safety communicationsservices. It is intended to accommodate Air Traffic Services (ATS),Airline Operational Control (AOC), Airline AdministrativeCommunications (AAC), and Airline Passenger Communications (APC).These four categories are recognized by the International CivilAviation Organization (ICAO) and the InternationalTelecommunications Union (ITU) which have assigned them prioritiesfor communications purposes (Radio Regulation Article S44 and ICAOAnnex 10, Volume II, 5.1.8). The system is to be designed to ensurethat aeronautical communications for safety and regularity offlight are not delayed by the transmission and reception of othertypes of messages.

The satcom architecture defines system characteristics to assurea worldwide level of communications interoperability. Satcom is tobe compatible and interoperable with external systems. Thispresumes the implementation of well-defined gateways andpeer-to-peer protocols. Routing and addressing schemes used are tobe compatible worldwide. The ICAO 24-bit aircraft address is to beused throughout satcom to ensure compatibility betweenorganizations and systems.

For packet-mode data services, two modes of operation arepermitted. These modes are referred to as Data-2 and Data-3 to beconsistent with industry standards. Data-2 operation does notinclude subnetwork layer protocol functions. User data packets aretransparently enveloped with a two-octet header and use the RLSlink layer services directly. Data-3 operation supports a SwitchedVirtual Circuit (SVC) subnetwork layer service which operates overthe RLS link layer service.

Interoperability has been accomplished by applying theInternational Standards Organization’s (ISO) Open SystemsInterconnection (OSI) Basic Reference Model (ISO 7498). Satcom dataservices are expected to conform, in the future, with guidelinesfor the Aeronautical Telecommunications Network (ATN) currentlybeing developed.

For circuit-mode services, interoperability has beenaccomplished through the use of layered design techniques inaccordance with International Telecommunication UnionTelecommunication Standardization Sector (ITU-T) designprinciples.

Edition:

12

Published:

06/27/2012

Number of Pages:

289

File Size:

1 file , 2.2 MB