© 2014 Rockwell Collins. All rights reserved.
© 2014 Rockwell Collins. All rights reserved.
Fundamentals of HF Data Link
© 2014 Rockwell Collins. All rights reserved.
Framework for Discussion
• General Overview – Propagation
• The Ground Component – Architecture – HFDL Ground Station
• The Airborne Component – Architecture – HF Data Radio
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© 2014 Rockwell Collins. All rights reserved.
Framework for Discussion
• ARINC Report – Provides guidelines or general info found by the airlines to be good
practices, often related to maintenance and support. • ARINC Report 634: HF Data Link System Design Guidance Material.
• ARINC Specification – Principally used to define either the physical packaging or mounting
of the avionics equipment, data communications standards or high-level computer language.
• ARINC Specification 635-4: HF Data Link Protocols.
• ARINC Characteristics – Define the form, fit, function and interfaces of avionics equipment
• ARINC Characteristic 719-5: Airborne HF / SSB System. • ARINC Characteristic 753-2: HF Data Link System.
ALL SPECS ARE AVAILABLE FROM ARINC.COM 3
© 2014 Rockwell Collins. All rights reserved.
© 2014 Rockwell Collins. All rights reserved.
General Overview
© 2014 Rockwell Collins. All rights reserved.
General Overview
• ARINC launched the world’s only High Frequency Data Link (HFDL) system in 1998.
• 85 worldwide customers. • Over 2600+ equipped aircraft with 4.8 million transmissions per
month.
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© 2014 Rockwell Collins. All rights reserved.
HFDL 101 … The Basics
• Long-range, beyond the line-of-sight communications take place in the HF radio spectrum from 2-30 MHz. – Over 167 frequencies used by the HFDL system worldwide. – Over 32 different frequencies operating at any one time.
– Air-ground message transmission speed varies depending on radio wave propagation conditions.
• 300, 600, 1200, 1800 bps.
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EHF Extremely high frequency 30-300 GHz SHF Superhigh frequency 3-30 GHz UHF Ultrahigh frequency 300-3,000 MHz VHF Very high frequency 30-300 MHz HF High frequency 2-30 MHz MF Medium frequency 300-3,000 kHz LF Low frequency 30-300 kHz
VLF Very low frequency 3-30 kHz Abbreviation Designation Frequency
HFDL
VHF SAT
SAT
© 2014 Rockwell Collins. All rights reserved.
HFDL 101 … Propagation
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One hop
Multi hop
Refraction of signal
Ionosphere
The ionosphere is a region of electrically charged particles or gases in the earth’s atmosphere, extending approx. 30-375
miles above the earth’s surface.
© 2014 Rockwell Collins. All rights reserved.
HFDL 101 … Propagation
• HFDL propagation is dependent on the ionosphere. – The ionosphere’s shape and
density change throughout the day and night.
– In order to compensate, the HFDL system must also change the HF frequencies used.
• The nature of HF propagation allows for signals to travel great distances through multi-hop propagation. – 15 ground stations provide
overlapping global coverage.
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© 2014 Rockwell Collins. All rights reserved.
© 2014 Rockwell Collins. All rights reserved.
The Ground Component
© 2014 Rockwell Collins. All rights reserved.
Architecture
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ARINC’s Central Processing System
(CPS)
HFDL Ground Station (HGS)
Ch1 Ch3 Ch2
ARINC Global Network Receive
Antenna
Transmit Antenna
Ground End Systems • Airline host processing • DSP services • CAA systems • Tower systems
VHF (POA) VDL
SATCOM
© 2014 Rockwell Collins. All rights reserved.
Worldwide Coverage
Areas of Primary coverage
Areas of Secondary coverage
Legend HFDL ground station
HF Ground Stations Alaska Bahrain Bolivia
California Canary Islands
Guam Hawaii Iceland Ireland
New York New Zealand
Panama Russia
South Africa Thailand
© 2014 Rockwell Collins. All rights reserved.
© 2014 Rockwell Collins. All rights reserved.
The Airborne Component
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Airborne Architecture
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Multi-Functional Cockpit Display Unit
Flight Management System
ACARS MU/CMU/ATSU
HF Data Radio (x2)
HF Coupler (x2)
HF Antenna
© 2014 Rockwell Collins. All rights reserved.
Equipage
• HFDL is certified as forward-fit on most large commercial transport aircraft. – Boeing
• B737-700 / 800 / 900 • B747-400 / 400F • B757-200 / 300 • B767-200 / 300 / 400 • B777-200 / 300 • B787 (future delivery)
– Airbus • A319 / 320 / 321 • A330 / 340 • A380 (HFDL is standard equipment)
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© 2014 Rockwell Collins. All rights reserved.
Equipage … cont.
• Supplemental Type Certificate (STC) available on many aircraft types. – A320 family – B737-800 – B747-200 / 300 / 400 – B757-200 / 300 – B767-200 / 300 / 400 – B777-200 – MD-11
– Rockwell Collins owns many of these
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© 2014 Rockwell Collins. All rights reserved.
Let’s Wrap This Up …
• HFDL ground and airborne components work together to make HFDL a highly reliable data link service.
• HFDL is a cost-effective alternative to satellite, but used in conjunction with satellite provides the most reliable long-range data link combination.
• Significant operational benefits to be gained from implementing HFDL.
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