Data Communications for the Air Transport Industry

Prepared by Richard M. Hambly

CNS Systems, Inc.

363 Hawick Court, Severna Park, Maryland 21146-1409

(410) 987-7835

CNS Systems, Inc. is dedicated to providing communication, navigation and surveillance solutions for the commercial and military transportation industries.

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:

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 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"