Page 19 - ITU-T Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring - Key findings, recommendations for next steps and future work

ITU-T Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring
Key findings, recommendations for next steps and future work

end of the flight. However, with a low number of distress situations, the global bandwidth needs will be a
fraction of that from continuous routine real-time data streaming.

An analysis illustrating the data transmission bandwidth performance needs for both continuous routine black
box streaming and TTFD modes of flight data transmission is provided in Appendix 4 of Deliverable 4. The
appendix has two sets of tables. The first set of tables describes the global bandwidth need and the global
data volumes generated if up to 20,000 aircraft were to be simultaneously streaming flight data. Three sets of
values are provided illustrating the data volumes and bandwidth needs associated with three example flight
data black box recording rates:
• Aircraft position data recording only;

• 64 words per second standard flight data recording (circa 1995 common standard);
• 1024 words per second (wps) standard flight data recording (circa 2015 common standard).
Flight data recorder (FDR) Aircraft position only 64 wps FDR 1024 wps FDR
standard
Bandwidth needed for routine 72 bps per (1) aircraft 768 bps per (1) aircraft 12.3 kbps per (1) aircraft
continuous FDR streaming

Global bandwidth needed 690 kbps for 10,000 aircraft 7.32 Mbps for 10,000 117 Mbps for 10,000 aircraft
aircraft

Global FDR 130 GB 1.4 TB 22 TB
data volume per month for 10,000 aircraft per month for 10,000 per month for 10,000 aircraft
aircraft

The 1024 wps FDR bandwidth analysis is really a worst case analysis and the overall global bandwidth needs
are likely to be significantly less than illustrated. This is because the analysis assumes no data compression
is achieved and the FDR standards and actual data volumes are expected to be much less on most aircraft in
service. While many newer aircraft record flight data at the 1024 wps standard, the most common standards
in use are 256 wps or less for narrow body aircraft and 512 wps or less for wide body aircraft.

Deliverable 4 Appendix 4 provides various TTFD analysis illustrating how many hours of flight data could be
transmitted through 432 kbps bandwidth based on a triggering event occurring at various times from 1 to 15
minutes prior to the end of the flight. Calculations are provided for 1024 wps, 512 wps, 256 wps and 64 wps
FDR standards and some extracted results of how much accumulated data could be streamed are shown below.
FDR standard Time of triggering event
2 minutes 5 minutes 10 minutes
before end of flight before end of flight before end of flight
1024 wps 1 flight hour of 2 hours of 5 hours of
data sent data sent data sent
512 wps 2 hours of 5 hours of 11 hours of
data sent data sent data sent
256 wps 4 hours of 11 hours of 23 hours of
data sent data sent data sent

64 wps 18 hours of 45 hours of 99 hours of
data sent data sent data sent

b) Data link systems performance

Information relating to the capabilities and bandwidth of various terrestrial and satellite data link technologies
are defined in Deliverable 4 Appendix 3. Appendix 3 includes two tables: one with terrestrial data link
characteristics for VHF digital link (VDL) Mode 0/A, VDL Mode 2, high frequency (HF) data link (DL), VDL

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