Originally Posted by jaysona

Here's some more information re: ACARS for you, should give you a couple of nights worth of (hopefully) good reading.

Typically ACARS messages fall into three general message types:
1. Air traffic control (ATC)

2. Aeronautical Operational Control (AOC)

3. Airline Administrative Control (AAC)

ACARS messages are typically sent using one of the following:

ARINC standards related to ACARS:

ARINC - 618 Air to ground protocol.
ARINC - 620 Ground to ground protocol.
ARINC - 623 Defines ATC related messages that can be received or sent via the ACARS (Excluding FMS generated).
ARINC - 633 Defines AOC air-ground and ground-ground messages that can be received or sent via the ACARS.
ARINC - 823 Part 1 Defines secure authentication for message exchange between aircraft & ground systems.

The ARINC standards and documents can be purchased by anyone from the ARINC store.

High level ICAO introductory document to ACARS.

Good introduction to ACARS by Universal Radio - used to sell PC based ACARS decoders.
http://www.universal-radio.com/catal...s/acarsweb.pdf
http://www.universal-radio.com/catal...ders/acars.pdf

SITA ACARS over IP position paper.

The ARINC AEEC is in the process of updating some of the ARINC standards and papers mentioned above.

Happy reading! ^