DOCUMENT SCOPE

VDL Mode 4 equipment provides:

• broadcast services including Automatic Dependent Surveillance - Broadcast (ADS-B), Traffic Information Service – Broadcast (TIS-B) and Flight Information Service – Broadcast (FIS-B) capabilities.

• A/G and A/A point-to-point communications services.

It is envisaged that manufacturers may provide equipment supporting:

• broadcast services only;

• point-to-point services only;

• both broadcast and point-to-point services.

This document defines the core functional requirements for the VDL Mode 4 Aircraft Transceiver necessary to support all types of equipment. This includes a simple position broadcast functionality.

This document does not address requirements for the full ADS-B message set, or for other broadcast applications that may be supported by the equipment. These are covered by ED-108A VDL Mode 4 MOPS Part 2: Additional Broadcast Requirements.

This document does not specify requirements which are exclusively required to support point-to-point communications including the interface to the Aeronautical Telecommunication Network (ATN) as defined in ATN SARPs [10].

Furthermore, the document does not address requirements related to any display of ADS-B information which may form part of the ADS-B equipment.

As the measured values of equipment performance may be a function of the method of measurement, standard test conditions and methods of test are recommended in this document.

This document uses the following mandating and recommendation phrases:

a. "Shall"

The use of the word "Shall" indicates a mandated criterion; i.e. compliance with the particular procedure or specification is mandatory and no alternative may be applied.

b. "Should"

The use of the word "Should" (and phrases such as "It is recommended that...", etc.) indicate that though the procedure or criterion is regarded as the preferred option, alternative procedures, specifications or criteria may be applied, provided that the manufacturer, installer or tester can provide information or data to adequately support and justify the alternative.