ARINC SPECIFICATION 631-7-2017 PDF

Full title and description

ARINC Specification 631-7:2017 — VHF Digital Link (VDL) Mode 2 Implementation Provisions. This edition (631-7, published 2017) documents the implementation provisions and design guidance for airborne and ground components implementing VDLM2 (VHF Data Link Mode 2) to support bit-oriented air–ground messaging in an OSI/ATN environment.

Abstract

This specification defines the functions, services and protocol mappings required to exchange bit-oriented data across VHF Data Link Mode 2 (VDLM2). It covers the subnetwork/link/physical layer aspects relevant to airborne and ground equipment, interfaces to the ATN Mobile Subnetwork Dependent Convergence Function (MSNDCF), and provisions to support Aeronautical Telecommunication Network (ATN) applications such as CPDLC and ATC/AOC messaging. The document is intended as implementation guidance to ensure interoperability between aircraft avionics and ground VDL infrastructure.

General information

• Status: Historical / superseded (replaced by ARINC 631-8:2020).
• Publication date: July 10, 2017 (edition 631-7).
• Publisher: ARINC Industry Activities (AEEC/ARINC).
• ICS / categories: 49.090 — On-board equipment and instruments.
• Edition / version: 631-7 (2017 revision / historical version).
• Number of pages: 245 pages (631-7:2017 historical edition).

Scope

Defines implementation provisions for VHF Digital Link Mode 2 (VDLM2) air–ground subnetworks and specifies how VDLM2 services map to OSI layer concepts and to the ICAO ATN forwarding/convergence interfaces. The scope includes airborne and ground-side behavior, message transfer procedures, link management (including multi‑frequency management and auto‑tune considerations), and test/interop considerations to enable CPDLC, ATS and AOC message delivery over VDLM2.

Key topics and requirements

• VDLM2 protocol description: subnetwork, link and physical layer functions for VHF Mode 2.
• Interfaces and mapping to ATN/MSNDCF to support ATN/CPDLC applications.
• Airborne and ground component responsibilities for message transfer, addressing and error handling.
• Frequency management and multi-frequency auto-tune provisions to support operational VDL networks.
• Interoperability and conformance guidance, including test cases and procedures for verifying avionics/ground compatibility.
• Backward/forward compatibility notes relative to ACARS and other legacy data-link services.

Typical use and users

Used by avionics engineers, system integrators, aircraft manufacturers, ground network operators (VDL service providers), test laboratories and certification authorities. Typical tasks include designing VDLM2-capable radios and avionics interfaces, implementing ATN/CPDLC connectivity, validating interoperability with ground stations, and preparing certification evidence for airborne equipment and ground infrastructure.

Related standards

Closely related to ICAO VDLM2 SARPs and ICAO Doc 9776 (Manual on VDL Mode 2), ARINC specifications for related avionics interfaces, and ATN/OSI specifications used for CPDLC and ATS messaging. Later ARINC 631-8:2020 is the subsequent (current) edition that supersedes 631-7.

Keywords

VDL, VDLM2, VHF Data Link, ARINC 631, ATN, MSNDCF, CPDLC, ACARS, air–ground messaging, avionics, VHF radio, interoperability.

FAQ

Q: What is this standard?

A: ARINC 631-7:2017 is the ARINC implementation provisions document for VHF Digital Link (VDL) Mode 2, providing engineering and interoperability guidance for airborne and ground VDLM2 implementations.

Q: What does it cover?

A: It covers the VDLM2 subnetwork, link and physical layer behaviors, interfaces to ATN/MSNDCF, message transfer procedures, frequency management, and interoperability/testing guidance for CPDLC, ATS and AOC type services over VHF.

Q: Who typically uses it?

A: Avionics manufacturers, aircraft integrators, ground network operators, avionics test houses and certification bodies use the standard to design, validate and certify VDLM2-capable equipment and networks.

Q: Is it current or superseded?

A: ARINC 631-7:2017 is a historical edition. It was superseded by ARINC 631-8 (published July 2020); users implementing new systems should refer to the 631-8:2020 edition for the most recent provisions.

Q: Is it part of a series?

A: Yes — ARINC 631 is a multi‑revision specification (history of supplements and numbered revisions). The 631 series documents VDLM2 implementation provisions and has been updated via multiple editions and supplements; 631-7 is one historical revision in that series.

Q: What are the key keywords?

A: VDL, VDLM2, VHF Data Link, CPDLC, ATN, MSNDCF, ACARS, air–ground communications, interoperability, avionics.