Page 25 - ITU-T Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring - Avionics and Aviation Communications Systems

ITU-T Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring
Avionics and Aviation Communications Systems

the utilization of existing certified aircraft tracking. ADS-C is an important building block as it currently
fully supports the conclusions of the Aircraft Tracking Task Force (ATTF) that a near-term goal of global
tracking of airline flights should be pursued as a matter of priority. It is also consistent with the findings
from the draft ICAO global aeronautical distress and safety system (GADSS) concept of operation.

11. On-board data link infrastructure

11.1 Current

11.1.1 Introduction

This section describes existing data link avionics system infrastructure available on aircraft today. Appendix 3
provides more details. On-board data link systems are typically divided according to the following categories.
Systems that are a part of and support:
i) The flight deck – The aircraft control domain (ACD);

ii) The aircraft information services (AIS) data domain.
iii) Data link systems that are a part of and support the cabin or the passenger information and entertainment
services (PIES) data domain.
iv) Data link systems that are limited to ground use only. Also known as airport surface data communications
systems that include Wi-Fi (GateLink) and cellular technologies; these systems are not considered further
in this Report since they are never used inflight and therefore cannot support flight tracking or real-time
in-flight data streaming.
Data link systems that are required for critical required data communications between air crew and air traffic
control and airline operations control are described as supporting safety services. For example, aircraft
separation through the use of ADS-C is described as a data link safety service.

For a data link system to be accepted and qualified as suitable for safety services, the communications avionics
and the associated data link services must meet stringent performance requirements. These avionics systems
typically take years to specify, develop and then qualify before they undergo months of flight trials in order
to demonstrate the required level of dependability needed for safety services. Aeronautical mobile-satellite
(route) service (AMS(R)S) is designated by ICAO and ITU for a two-way communication via satellite(s) pertaining
to the safety and regularity of the flight along national or international civil air routes. To date, Inmarsat I-3
(Classic Aero) and 1-4 Classic Aero service are approved for safety services. Iridium is now being used for safety
services and Inmarsat I-4 (SwiftBroadband) is also now undergoing FANS over SwiftBroadband evaluation for
safety services.

Aeronautical mobile (route) service (AM(R)S) is designated by ITU for a two-way communication pertaining to
the safety and regularity of the flight. To date, VHF data link including VDL Mode 2 is the only terrestrial data
link approved and used for safety services.
Air-to-ground (ATG) cellular, Ku-band and Ka-band data link systems are not approved for safety services.

11.1.2 On-board data link systems infrastructure – AIS domain/flight deck systems

Most data link systems for flight deck and avionics use are associated with the ACARS system which is available
and used on-board most aircraft today, especially for long haul trans-oceanic aircraft. There is some use of other
airborne data links for flight deck use but this is rather limited compared to the use of data links associated
with ACARS. ACARS systems and associated data links shall be considered first followed by a discussion on
other data links utilized for the flight deck.

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