3. INTRODUCTION
• ACARS: Aircraft Communications Addressing and Reporting System
• Full-duplex datalink
• Effort to improve data integrity and reduce crew workload
• Introduced in 1978
• 2400 baud rate
4.
5. WORKING
• An on board person or system can create a message and send it via ACARS to a system or
user on the ground, and vice versa.
• Remote Ground Stations
• VHF Subnetwork: Line-of-sight propagation
• HF Subnetwork: Continental Coverage
• Satellite Communication: World-wide coverage
6. USES
• OOOI Events: Out of the gate, Off the ground, On the ground, and Into the gate
• ADS : Automatic Dependent Surveillance – Position reporting of a/c
• Flight management system interface: Flight plans and weather conditions etc.,
• Maintenance data download: Operational performance
• Interactive crew interface: Crew communication
• Online black-box
7. EXAMPLE MESSAGE
A typical ACARS VHF transmission.
Mode
A
Aircraft
B-18722
Ack
NAK
Block id
2
Flight
CI5118
Label
B9
Msg No.
L05A
Message
/KLAX.TI2/024KLAXA91A1
8. WHAT ARE WE USING TODAY?
• Aircraft Communication Addressing and Reporting System (ACARS)
• Character based transmissions
• 2400 bps transmission speeds
• In use since 1978
• Current statistics (ARINC)
• Service provided through 196 stations
• System is reaching it’s capacity in U.S./Europe
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9. PROBLEM
•
Growing number of ACARS aircraft
•
Potential new demand from new participants
•
•
Military: Non-Tactical Aircraft, Air National Guard
•
•
Civil: Large Scheduled (Regional), Cargo, and Business
Estimated potential at larger scale
Increasing number of data link applications
•
•
Crew Management
•
•
Aircraft Performance
In-flight Operations
Many areas are already experiencing congestion on en route frequencies
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10. SOLUTION
• Managing spectrum congestion and availability will be a growing and
continuing concern for the airline industry.
• Over the next 20 years, ACARS will be superseded by the Aeronautical
Telecommunications Network (ATN) protocol for Air Traffic Control
communications and by the Internet Protocol for airline communications.