Page 14 - 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

transmission that may meet GADSS flight data recovery objectives. The purpose of this Report, "real-time data"
is defined as data with adequate update rate and latency to meet the operational requirement.

8.2 Background

Data communication capabilities provide for the integration of capabilities to exchange information between
ground-based operations and aircraft. To establish more context, the following describes some of the primary
parameters which are considered:

i) Communication transaction time – The maximum time for the completion of the operational
communication transaction after which the initiator should revert to an alternative procedure.
ii) Continuity – The probability that an operational communication transaction can be completed within
the communication transaction time.
iii) Availability – The probability that an operational communication transaction can be initiated when needed.

iv) Integrity – The probability that communication transactions are completed within the communication
transaction time with undetected error.

v) Further definitions with regard to current communication standards are:
1. RCP 240 would be used for controller intervention capability supporting separation assurance in a
30/30 separation environment.
2. RCP 400 would be used for controller intervention capability supporting separation assurance in current
environments where separations are greater than 30/30 and alternative technologies are planned

8.3 Data streaming

Data streaming can and will be used for a variety of purposes. Its application may range from search and rescue,
accident investigation to aircraft and engine maintenance management. The performance requirements
will vary depending on the application. Further definitional work will be required to set out what will be the
required performance for real-time data streaming based on the expected application. It is anticipated that
real-time data streaming performance values or standards are likely to be selected based on the anticipated
ICAO SARPs for GADSS.

8.4 Bandwidth needs analysis for real-time flight data transmission and data link systems
performance summary

A study of the bandwidth needs for real-time flight data streaming and resulting data volumes generated as
well as a survey of various terrestrial and satellite data link systems in use on aircraft today are provided in
Appendices 4 and 3, respectively, and are summarized below.

8.4.1 Bandwidth needs analysis for real-time flight data transmission

There are two possible modes of real-time flight data transmission that may be considered:

• The first mode is continuous real-time flight data streaming at all times even during normal operations;
• The second mode is for triggered transmission of flight data which involves manual or automated
activation of flight data streaming when a distress situation is encountered.
Performing routine and continuous real-time flight data streaming on aircraft generates a relatively low
bandwidth requirement per aircraft but generates the largest global requirement.
Relevant studies, including the report published by BEA after the 2009 Air France Flight 447 accident and
the National Transportation Safety Board (NTSB) Recommendation letter published on 22 January 2015,

4