Page 28 - 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

iii) GoGo's ATG-4 can provide 3.6 Mbps off the aircraft and 9.8 Mbps to the aircraft;

iv) Ku-band offers 1 Mbps off the aircraft and 50 Mbps or more to the aircraft;
v) Ka-band offers 5 Mbps off the aircraft and 50 Mbps or more to the aircraft.
All of these systems provide relatively fast data rates off the aircraft compared to ACARS data links, i.e. between
432 kbps and 5 Mbps which is many times more than what would be needed to support black box flight data
streaming. These cabin links are also much less expensive per MB to use and are also well suited to transfer
non-safety service, non-ATC ACARS traffic.

Iridium has been installed by some airlines supporting cabin operations but due to the narrow bandwidth
(2.4 kbps) the applications are relatively limited, for example, to live credit card validation or telemedicine.

11.1.5 Conclusion – On-board data link infrastructure (Current)

• Flight deck ACARS data link systems are already used to perform flight tracking. Together with FMS, ACARS
enables ADS-C. Since FMS, ACMS and AOC capabilities are all integrated with ACARS, these may be used
to expand flight tracking without installing additional equipment on the aircraft. With ACMS and AOC
being user modifiable software (UMS), they are particularly well suited to hosting trigger algorithms that
could be used to implement abnormal and autonomous distress tracking. With the fullest access to flight
data parameters, ACMS is most likely the best suited and could be used for abnormal and autonomous
distress tracking. The probable downside of using ACARS data links is their high transmission cost, but
depending on the type of transmission/streaming/function, this should be expected to be low; this may
not be a major concern.
• Current flight deck data link systems are not suited to full flight data streaming due to the narrow bandwidth
and high transmission costs of these data links, and due to the fact that flight deck communications are
not IP-based today but are really designed around messaging using special ARINC protocols.
• Cabin data link systems such as Ku-band, Ka-band and L-band Inmarsat SwiftBroadband where approved
do provide very high bandwidth and low cost data transfer that supports routine tracking, distress tracking
and even full flight black box streaming. ATG links, since they operate only overland, are not suited for
trans-oceanic operations. Cabin broadband SatCom data link systems, although they do not have the
same current equipage rates as flight deck data link systems, are increasingly being installed to provide
passenger Internet access and this is forecasted to continue at a high installation growth rate.

• An apparent limitation of cabin data links is that they do not have native access to flight data system
sources on board. There are network enabled IP data routing systems that have access to flight data that
could be connected with the cabin broadband data link systems, and with time most of the Ku-band and
Ka-band services will cover more and more of flight routes. Cabin data links also have an issue of being
within the PIES domain on the aircraft, which means there are additional security measures that may
be needed to protect AIS domain systems from potential attacks from the cabin. However, the industry
is already working on security solutions to enable AIS and PIES domains to be connected.
• The diagram below illustrates how on-board information systems as described in section 10.1 may be
connected with broadband data link systems to enable real-time data transmission.

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