Data Communications for the Air Transport Industry

Data Communications for the Air Transport Industry
- Applications
- Technologies
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:

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.

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 ACARS Will have "hidden transmitter" problem unless ground stations are synchronized (Slotted Aloha)
Mode 3	D8PSK @ 31,500 bps	TDMA 30 ms/slot 4 slots/frame	Supports both voice and data. 4 "channels"
Mode 4	FM/GMSK @ 19,200 bps	STDMA 6.67 ms/slot 9000 slots/frame	dynamic allocation of slot assignments to support periodic and aperiodic data air-to-air communications aircraft as relay/router
DO-217	D8PSK @ 31,500 bps	TDM 62.5 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