- Data Communications for the Air Transport Industry
- CNS Ground Station
- R&D Projects
- NASA TAP/LVLASO (Phase 1 and Phase 2)
- FAA Airport Surface Traffic Automation (ASTA)
- Naval Air Warfare Center FASSTER
- Other Industries
- Summary
Data Communications for the Air Transport Industry:
Applications
- Preflight
- Pilot Information Gathering and Planning: The entire flight plan can be delivered to the Flight Management System (FMS).
- Dispatch release and load information.
- ATC Departure Clearances
- Relieves Voice Frequency Congestion.
- Out/Off/On/In (OOOI) events
- Used to determine crew duty cycle times, maintenance intervals, and crew pay.
- Real-time reporting of engine data
- Along with a reactive maintenance program, allows airlines to obtain extended warranties, resulting in major cost savings.
- Gate Information
- Arrival gate information
- Connecting gate information
- Flight Following
- ETA report results in effective control of flight operations.
- Automatic Dependent Surveillance (ADS) automatically generates position reports at predetermined time intervals directly from the navigation system.
- Enhanced dispatch monitoring of operations ensures system/hub operations integrity.
- More Efficient Scheduling of Ground Services and Gates
- Eventually, ATC will use ADS to enhance air traffic management.
- Automatic Terminal Information Service (ATIS)
- Monitoring ATIS voice broadcasts during periods of high cockpit workload is a time-consuming distraction.
- The aircraft does not need to be in VHF voice range of the airport, and the pilot can view the information at his or her discretion.
- Weather Information
- Weather advisories, Notices to Airmen (NOTAMs) changes, and hazard reports, such as wind shear/microburst alerts.
Today’s ACARS Applications
Data Communications for the Air Transport Industry:
VHF Data Link Technologies
| Type | Modulation | Channel Access | Application Notes |
|---|---|---|---|
| Mode 1 (ACARS) | AM/MSK @ 2400 bps | CSMA | Suffers from low data rate and “hidden transmitter” problems. |
| Mode 2 | D8PSK@ 31,500 bps | CSMA | Optimized for aperiodic air-ground communications as a replacement for ACARSWill have “hidden transmitter” problem unless ground stations are synchronized (Slotted Aloha) |
| Mode 3 | D8PSK@ 31,500 bps | TDMA30 ms/slot4 slots/frame | Supports both voice and data.4 “channels” |
| Mode 4 | FM/GMSK@ 19,200 bps | STDMA6.67 ms/slot9000 slots/frame | dynamic allocation of slot assignments to support periodic and aperiodic dataair-to-air communicationsaircraft as relay/router |
| DO-217 | D8PSK@ 31,500 bps | TDM62.5 ms/slot, 8 slots/frame | Ground to Air broadcast (DGPS, navigation information)8 “channels” |
Other Data Link Technologies
- Mode-S Data Link
- 1Mbps, 1030 MHz up, 4Mbps 1090 MHz down, talk when ready (ALOHA)
- 14NMi range air-to-air, up to 150Nmi air-to-ground
- TCAS uses 56-bit burst squitter
- ADS-B adds two additional 112-bit squitter messages