ETSI EN 302 842-3 applies to the following radio equipment types:

• Very High Frequency (VHF) Digital Link (VDL) Mode 4 aeronautical mobile (airborne) radio transmitters, transceivers and receivers for air-ground and air-air communications operating in the VHF band, using Gaussian Filtered Frequency Shift Keying (GFSK) modulation with 25 kHz channel spacing and capable of tuning to any of the 25 kHz channels from 112,000 MHz to 136,975 MHz as defined in ICAO VDL SARPs [i.2].

The present document provides part 3 of the technical specifications.

The present document is designed to ensure that equipment certified to it will be compatible with the relevant ICAO VDL SARPs [i.2] and ICAO VDL4 Technical Manual [i.1].

Manufacturers should note that in future the tuning range for the transmitter and the receiver may also cover any 25 kHz channel from 108,000 MHz to 111,975 MHz.

The present document applies to "aeronautical mobile (airborne and in some cases ground vehicles)" equipment which will hereinafter be referred to as "mobile" equipment.

The scope of the present document is limited to mobile stations. The equivalent specification for ground stations is ETSI EN 301 842 [i.7].

A description of the scope of the VDL Mode 4 system is provided in part 2 of these technical specifications (see ETSI EN 302 842-2 [2], clause 1).